Add HasStatus instance for Headers (that defers StatusOf to underlying value) (#1649)

* Add HasStatus instance for Headers (that defers StatusOf to underlying value)

* changelog.d/1649

.github/workflows/master.yml

@@ -20,6 +20,7 @@ jobs:
           - "8.10.7"
           - "9.0.2"
           - "9.2.2"
+          - "9.4.2"
 
     steps:
     - uses: actions/checkout@v2
@@ -59,9 +60,6 @@ jobs:
         cabal test all
 
     - name: Run doctests
-      # doctests are broken on GHC 9 due to compiler bug:
-      # https://gitlab.haskell.org/ghc/ghc/-/issues/19460
-      continue-on-error: ${{ matrix.ghc == '9.0.1' }}
       run: |
         # Necessary for doctest to be found in $PATH
         export PATH="$HOME/.cabal/bin:$PATH"
@@ -78,40 +76,40 @@ jobs:
         (cd servant-conduit && eval $DOCTEST)
         (cd servant-pipes && eval $DOCTEST)
 
-  stack:
-    name: stack / ghc ${{ matrix.ghc }}
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        stack: ["2.7.3"]
-        ghc: ["8.10.7"]
+  # stack:
+  #   name: stack / ghc ${{ matrix.ghc }}
+  #   runs-on: ubuntu-latest
+  #   strategy:
+  #     matrix:
+  #       stack: ["2.7.5"]
+  #       ghc: ["8.10.7"]
 
-    steps:
-    - uses: actions/checkout@v2
+  #   steps:
+  #   - uses: actions/checkout@v2
 
-    - uses: haskell/actions/setup@v1
-      name: Setup Haskell Stack
-      with:
-        ghc-version: ${{ matrix.ghc }}
-        stack-version: ${{ matrix.stack }}
+  #   - uses: haskell/actions/setup@v1
+  #     name: Setup Haskell Stack
+  #     with:
+  #       ghc-version: ${{ matrix.ghc }}
+  #       stack-version: ${{ matrix.stack }}
 
-    - uses: actions/cache@v2.1.3
-      name: Cache ~/.stack
-      with:
-        path: ~/.stack
-        key: ${{ runner.os }}-${{ matrix.ghc }}-stack
+  #   - uses: actions/cache@v2.1.3
+  #     name: Cache ~/.stack
+  #     with:
+  #       path: ~/.stack
+  #       key: ${{ runner.os }}-${{ matrix.ghc }}-stack
 
-    - name: Install dependencies
-      run: |
-        stack build --system-ghc --test --bench --no-run-tests --no-run-benchmarks --only-dependencies
+  #   - name: Install dependencies
+  #     run: |
+  #       stack build --system-ghc --test --bench --no-run-tests --no-run-benchmarks --only-dependencies
 
-    - name: Build
-      run: |
-        stack build --system-ghc --test --bench --no-run-tests --no-run-benchmarks
+  #   - name: Build
+  #     run: |
+  #       stack build --system-ghc --test --bench --no-run-tests --no-run-benchmarks
 
-    - name: Test
-      run: |
-        stack test --system-ghc
+  #   - name: Test
+  #     run: |
+  #       stack test --system-ghc
 
   ghcjs:
     name: ubuntu-latest / ghcjs 8.6

cabal.project

@@ -47,6 +47,7 @@ packages:
   doc/cookbook/using-custom-monad
   doc/cookbook/using-free-client
   -- doc/cookbook/open-id-connect
+  doc/cookbook/managed-resource
 
 tests: True
 optimization: False

changelog.d/1556

@@ -0,0 +1,81 @@
+synopsis: Display capture hints in router layout
+prs: #1556
+
+description: {
+
+This PR enhances the `Servant.Server.layout` function, which produces a textual description of the routing layout of an API. More precisely, it changes `<capture>` blocks, so that they display the name and type of the variable being captured instead.
+
+Example:
+
+For the following API
+```haskell
+type API =
+       "a" :> "d" :> Get '[JSON] NoContent
+  :<|> "b" :> Capture "x" Int :> Get '[JSON] Bool
+  :<|> "a" :> "e" :> Get '[JSON] Int
+```
+
+we previously got the following output:
+
+```
+/
+├─ a/
+│  ├─ d/
+│  │  └─•
+│  └─ e/
+│     └─•
+└─ b/
+   └─ <capture>/
+      ├─•
+      ┆
+      └─•
+```
+
+now we get:
+
+```
+/
+├─ a/
+│  ├─ d/
+│  │  └─•
+│  └─ e/
+│     └─•
+└─ b/
+   └─ <x::Int>/
+      ├─•
+      ┆
+      └─•
+```
+
+This change is achieved by the introduction of a CaptureHint type, which is passed as an extra argument to the CaptureRouter and CaptureAllRouter constructors for the Router' type.
+CaptureHint values are then used in routerLayout, to display the name and type of captured values, instead of just `<capture>` previously.
+
+N.B.:
+Because the choice smart constructor for routers can aggregate Capture combinators with different capture hints, the Capture*Router constructors actually take a list of CaptureHint, instead of a single one.
+
+This PR also introduces Spec tests for the routerLayout function.
+
+Warning:
+This change is potentially breaking, because it adds the constraint `Typeable a` to all types that are to be captured. Because all types are typeable since GHC 7.10, this is not as bad as it sounds ; it only break expressions where `a` is quantified in an expression with `Capture a`.
+In those cases, the fix is easy: it suffices to add `Typeable a` to the left-hand side of the quantification constraint.
+
+For instance, the following code will no longer compile:
+```haskell
+type MyAPI a = Capture "foo" a :> Get '[JSON] ()
+
+myServer :: forall a. Server (MyAPI a)
+myServer = const $ return ()
+
+myApi :: forall a. Proxy (MyAPI a)
+myApi = Proxy
+
+app :: forall a. (FromHttpApiData a) => Application
+app = serve (myApi @a) (myServer @a)
+```
+
+Indeed, `app` should be replaced with:
+```haskell
+app :: forall a. (FromHttpApiData a, Typeable a) => Application
+app = serve (myApi @a) (myServer @a)
+```
+}

changelog.d/1569

@@ -0,0 +1,13 @@
+synopsis: Encode captures using toEncodedUrlPiece
+prs: #1569
+issues: #1511
+
+description: {
+The `servant-client` library now makes direct use of `toEncodedUrlPiece` from `ToHttpApiData`
+to encode captured values when building the request path. It gives user freedom to implement
+URL-encoding however they need.
+
+Previous behavior was to use `toUrlPiece` and URL-encode its output using `toEncodedUrlPiece`
+from the `Text` instance of `ToHttpApiData`. The issue with this approach is that
+`ToHttpApiData Text` is overly zealous and also encodes characters, such as `*`, which are perfectly valid in a URL.
+}

changelog.d/1573

@@ -0,0 +1,2 @@
+synopsis: Add API docs for ServerT
+prs: #1573

changelog.d/1580

@@ -0,0 +1,12 @@
+synopsis: Allow IO in validationKeys
+prs: #1580
+issues: #1579
+
+description: {
+
+Currently validationKeys are a fixed JWKSet. This does not work with OIDC
+providers such as AWS Cognito or Okta, which regularly fetching jwks_uri to
+discover new and expired keys.
+
+This change alters the type of validationKeys from JWKSet to IO JWKSet.
+}

changelog.d/1589

@@ -0,0 +1,2 @@
+synopsis: Only include question mark for nonempty query strings
+prs: 1589

changelog.d/1595

@@ -0,0 +1,2 @@
+synopsis: Run ClientEnv's makeClientRequest in IO.
+prs: #1595

changelog.d/1606

@@ -0,0 +1,10 @@
+synopsis: Handle Cookies correctly for RunStreamingClient
+prs: #1606
+issues: #1605
+
+description: {
+
+Makes performWithStreamingRequest take into consideration the
+CookieJar, which it previously didn't.
+
+}

changelog.d/1638

@@ -0,0 +1,2 @@
+synopsis: Add Functor instance to AuthHandler.
+prs: #1638

changelog.d/1649

@@ -0,0 +1,8 @@
+synopsis: Add HasStatus instance for Headers (that defers StatusOf to underlying value)
+prs: #1649
+
+description: {
+
+Adds a new HasStatus (Headers hs a) instance (StatusOf (Headers hs a) = StatusOf a)
+
+}

doc/cookbook/index.rst

@@ -37,3 +37,4 @@ you name it!
   sentry/Sentry.lhs
   testing/Testing.lhs
   open-id-connect/OpenIdConnect.lhs
+  managed-resource/ManagedResource.lhs

doc/cookbook/managed-resource/ManagedResource.lhs

@@ -0,0 +1,114 @@
+# Request-lifetime Managed Resources
+
+Let's see how we can write a handle that uses a resource managed by Servant. The resource is created automatically by Servant when the server recieves a request, and the resource is automatically destroyed when the server is finished handling a request.
+
+As usual, we start with a little bit of throat clearing.
+
+
+``` haskell
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE TypeOperators #-}
+import Control.Concurrent
+import Control.Exception (bracket, throwIO)
+import Control.Monad.IO.Class
+import Control.Monad.Trans.Resource
+import Data.Acquire
+import Network.HTTP.Client (newManager, defaultManagerSettings)
+import Network.Wai.Handler.Warp
+import Servant
+import Servant.Client
+import System.IO
+```
+
+Here we define an API type that uses the `WithResource` combinator. The server handler for an endpoint with a `WithResource res` component will receive a value of that type as an argument.
+
+``` haskell
+type API = WithResource Handle :> ReqBody '[PlainText] String :> Post '[JSON] NoContent
+
+api :: Proxy API
+api = Proxy
+```
+
+But this resource value has to come from somewhere. Servant obtains the value using an Acquire provided in the context. The Acquire knows how to both create and destroy resources of a particular type.
+
+``` haskell
+appContext :: Context '[Acquire Handle]
+appContext = acquireHandle :. EmptyContext
+
+acquireHandle :: Acquire Handle
+acquireHandle = mkAcquire newHandle closeHandle
+
+newHandle :: IO Handle
+newHandle = do
+  putStrLn "opening file"
+  h <- openFile "test.txt" AppendMode
+  putStrLn "opened file"
+  return h
+
+closeHandle :: Handle -> IO ()
+closeHandle h = do
+  putStrLn "closing file"
+  hClose h
+  putStrLn "closed file"
+```
+
+Now we create the handler which will use this resource. This handler will write the request message to the System.IO.Handle which was provided to us. In some situations the handler will succeed, but in some in will fail. In either case, Servant will clean up the resource for us.
+
+``` haskell
+server :: Server API
+server = writeToFile
+
+  where writeToFile :: (ReleaseKey, Handle) -> String -> Handler NoContent
+        writeToFile (_, h) msg = case msg of
+          "illegal" -> error "wait, that's illegal!"
+          legalMsg -> liftIO $ do
+            putStrLn "writing file"
+            hPutStrLn h legalMsg
+            putStrLn "wrote file"
+            return NoContent
+```
+
+Finally we run the server in the background while we post messages to it.
+
+``` haskell
+runApp :: IO ()
+runApp = run 8080 (serveWithContext api appContext $ server)
+
+postMsg :: String -> ClientM NoContent
+postMsg = client api
+
+main :: IO ()
+main = do
+  mgr <- newManager defaultManagerSettings
+  bracket (forkIO $ runApp) killThread $ \_ -> do
+    ms <- flip runClientM (mkClientEnv mgr (BaseUrl Http "localhost" 8080 "")) $ do
+      liftIO $ putStrLn "sending hello message"
+      _ <- postMsg "hello"
+      liftIO $ putStrLn "sending illegal message"
+      _ <- postMsg "illegal"
+      liftIO $ putStrLn "done"
+    print ms
+```
+
+This program prints
+
+```
+sending hello message
+opening file
+opened file
+writing file
+wrote file
+closing file
+closed file
+sending illegal message
+opening file
+opened file
+closing file
+closed file
+wait, that's illegal!
+CallStack (from HasCallStack):
+  error, called at ManagedResource.lhs:63:24 in main:Main
+Left (FailureResponse (Request {requestPath = (BaseUrl {baseUrlScheme = Http, baseUrlHost = "localhost", baseUrlPort = 8080, baseUrlPath = ""},""), requestQueryString = fromList [], requestBody = Just ((),text/plain;charset=utf-8), requestAccept = fromList [], requestHeaders = fromList [], requestHttpVersion = HTTP/1.1, requestMethod = "POST"}) (Response {responseStatusCode = Status {statusCode = 500, statusMessage = "Internal Server Error"}, responseHeaders = fromList [("Transfer-Encoding","chunked"),("Date","Thu, 24 Nov 2022 21:04:47 GMT"),("Server","Warp/3.3.23"),("Content-Type","text/plain; charset=utf-8")], responseHttpVersion = HTTP/1.1, responseBody = "Something went wrong"}))
+```
+
+and appends to a file called `test.txt`. We can see from the output that when a legal message is sent, the file is opened, written to, and closed. We can also see that when an illegal message is sent, the file is opened but not written to. Crucially, it is still closed even though the handler threw an exception.

doc/cookbook/managed-resource/managed-resource.cabal

@@ -0,0 +1,30 @@
+cabal-version:       2.2
+name:                cookbook-managed-resource
+version:             0.1
+synopsis:            Simple managed resource cookbook example
+homepage:            http://docs.servant.dev/
+license:             BSD-3-Clause
+license-file:        ../../../servant/LICENSE
+author:              Servant Contributors
+maintainer:          haskell-servant-maintainers@googlegroups.com
+build-type:          Simple
+tested-with:         GHC==9.4.2
+
+executable cookbook-managed-resource
+  main-is:             ManagedResource.lhs
+  build-depends:       base == 4.*
+                     , text >= 1.2
+                     , aeson >= 1.2
+                     , servant
+                     , servant-client
+                     , servant-server
+                     , warp >= 3.2
+                     , wai >= 3.2
+                     , http-types >= 0.12
+                     , markdown-unlit >= 0.4
+                     , http-client >= 0.5
+                     , transformers
+                     , resourcet
+  default-language:    Haskell2010
+  ghc-options:         -Wall -pgmL markdown-unlit
+  build-tool-depends: markdown-unlit:markdown-unlit

doc/cookbook/open-id-connect/OpenIdConnect.lhs

@@ -330,7 +330,7 @@ data Customer = Customer {
 ```
 
 Here is the code that displays the homepage.
-It should contain a link to the the `/login` URL.
+It should contain a link to the `/login` URL.
 When the user clicks on this link it will be redirected to Google login page
 with some generated information.
 

doc/cookbook/using-free-client/UsingFreeClient.lhs

@@ -119,7 +119,7 @@ Now we can use `servant-client`'s internals to convert servant's `Request`
 to http-client's `Request`, and we can inspect it:
 
 ```haskell
-        let req' = I.defaultMakeClientRequest burl req
+        req' <- I.defaultMakeClientRequest burl req
         putStrLn $ "Making request: " ++ show req'
 ```
 

doc/cookbook/uverb/UVerb.lhs

@@ -199,7 +199,7 @@ parsers in the hope that the ones that should will always error out so
 you can try until the right one returns a value.)
 
 [servant-exceptions](https://github.com/ch1bo/servant-exceptions) is
-another shot at at the problem.  It is inspired by
+another shot at the problem.  It is inspired by
 servant-checked-exceptions, so it may be worth taking a closer look.
 The README claims that
 [cardano-sl](https://github.com/input-output-hk/cardano-sl) also has

doc/requirements.txt

@@ -1,3 +1,4 @@
 recommonmark==0.5.0
 Sphinx==1.8.4
 sphinx_rtd_theme>=0.4.2
+jinja2<3.1.0

servant-auth/servant-auth-client/servant-auth-client.cabal

@@ -31,7 +31,7 @@ library
   default-extensions: ConstraintKinds DataKinds DefaultSignatures DeriveFoldable DeriveFunctor DeriveGeneric DeriveTraversable FlexibleContexts FlexibleInstances FunctionalDependencies GADTs KindSignatures MultiParamTypeClasses OverloadedStrings RankNTypes ScopedTypeVariables TypeFamilies TypeOperators
   ghc-options: -Wall
   build-depends:
-      base                >= 4.10     && < 4.17
+      base                >= 4.10     && < 4.18
     , bytestring          >= 0.10.6.0 && < 0.12
     , containers          >= 0.5.6.2  && < 0.7
     , servant-auth        == 0.4.*
@@ -50,7 +50,7 @@ test-suite spec
       test
   default-extensions: ConstraintKinds DataKinds DefaultSignatures DeriveFoldable DeriveFunctor DeriveGeneric DeriveTraversable FlexibleContexts FlexibleInstances FunctionalDependencies GADTs KindSignatures MultiParamTypeClasses OverloadedStrings RankNTypes ScopedTypeVariables TypeFamilies TypeOperators
   ghc-options: -Wall
-  build-tool-depends: hspec-discover:hspec-discover >=2.5.5 && <2.9
+  build-tool-depends: hspec-discover:hspec-discover >=2.5.5 && <2.10
 
   -- dependencies with bounds inherited from the library stanza
   build-depends:
@@ -62,7 +62,7 @@ test-suite spec
  
   -- test dependencies
   build-depends:
-      hspec                >= 2.5.5    && < 2.9
+      hspec                >= 2.5.5    && < 2.10
     , QuickCheck           >= 2.11.3   && < 2.15
     , aeson                >= 1.3.1.1  && < 3
     , bytestring           >= 0.10.6.0 && < 0.12
@@ -74,7 +74,7 @@ test-suite spec
     , transformers         >= 0.4.2.0  && < 0.6
     , wai                  >= 3.2.1.2  && < 3.3
     , warp                 >= 3.2.25   && < 3.4
-    , jose                 >= 0.7.0.0  && < 0.10
+    , jose                 >= 0.10     && < 0.11
   other-modules:
       Servant.Auth.ClientSpec
   default-language: Haskell2010

servant-auth/servant-auth-docs/servant-auth-docs.cabal

@@ -35,11 +35,11 @@ library
   default-extensions: ConstraintKinds DataKinds DefaultSignatures DeriveFoldable DeriveFunctor DeriveGeneric DeriveTraversable FlexibleContexts FlexibleInstances FunctionalDependencies GADTs KindSignatures MultiParamTypeClasses OverloadedStrings RankNTypes ScopedTypeVariables TypeFamilies TypeOperators
   ghc-options: -Wall
   build-depends:
-      base         >= 4.10    && < 4.17
+      base         >= 4.10    && < 4.18
     , servant-docs >= 0.11.2  && < 0.13
     , servant      >= 0.13    && < 0.20
     , servant-auth == 0.4.*
-    , lens         >= 4.16.1  && <5.2
+    , lens         >= 4.16.1  && <5.3
   exposed-modules:
       Servant.Auth.Docs
   default-language: Haskell2010
@@ -50,7 +50,7 @@ test-suite doctests
   build-depends:
     base,
     servant-auth-docs,
-    doctest             >= 0.16   && < 0.19,
+    doctest             >= 0.16   && < 0.21,
     QuickCheck          >= 2.11.3 && < 2.15,
     template-haskell
   ghc-options:         -Wall -threaded
@@ -64,7 +64,7 @@ test-suite spec
       test
   default-extensions: ConstraintKinds DataKinds DefaultSignatures DeriveFoldable DeriveFunctor DeriveGeneric DeriveTraversable FlexibleContexts FlexibleInstances FunctionalDependencies GADTs KindSignatures MultiParamTypeClasses OverloadedStrings RankNTypes ScopedTypeVariables TypeFamilies TypeOperators
   ghc-options: -Wall
-  build-tool-depends: hspec-discover:hspec-discover >=2.5.5 && <2.9
+  build-tool-depends: hspec-discover:hspec-discover >=2.5.5 && <2.10
 
   -- dependencies with bounds inherited from the library stanza
   build-depends:
@@ -78,7 +78,7 @@ test-suite spec
   -- test dependencies
   build-depends:
       servant-auth-docs
-    , hspec             >= 2.5.5  && < 2.9
+    , hspec             >= 2.5.5  && < 2.10
     , QuickCheck        >= 2.11.3 && < 2.15
 
   default-language: Haskell2010

servant-auth/servant-auth-server/servant-auth-server.cabal

@@ -31,7 +31,7 @@ library
   default-extensions: ConstraintKinds DataKinds DefaultSignatures DeriveFoldable DeriveFunctor DeriveGeneric DeriveTraversable FlexibleContexts FlexibleInstances FunctionalDependencies GADTs KindSignatures MultiParamTypeClasses OverloadedStrings RankNTypes ScopedTypeVariables TypeFamilies TypeOperators
   ghc-options: -Wall
   build-depends:
-      base                    >= 4.10     && < 4.17
+      base                    >= 4.10     && < 4.18
     , aeson                   >= 1.0.0.1  && < 3
     , base64-bytestring       >= 1.0.0.1  && < 2
     , blaze-builder           >= 0.4.1.0  && < 0.5
@@ -41,17 +41,17 @@ library
     , data-default-class      >= 0.1.2.0  && < 0.2
     , entropy                 >= 0.4.1.3  && < 0.5
     , http-types              >= 0.12.2   && < 0.13
-    , jose                    >= 0.7.0.0  && < 0.10
-    , lens                    >= 4.16.1   && < 5.2
-    , memory                  >= 0.14.16  && < 0.18
+    , jose                    >= 0.10     && < 0.11
+    , lens                    >= 4.16.1   && < 5.3
+    , memory                  >= 0.14.16  && < 0.19
     , monad-time              >= 0.3.1.0  && < 0.4
-    , mtl                     >= 2.2.2    && < 2.3
+    , mtl                     ^>= 2.2.2   || ^>= 2.3.1
     , servant                 >= 0.13     && < 0.20
     , servant-auth            == 0.4.*
     , servant-server          >= 0.13     && < 0.20
     , tagged                  >= 0.8.4    && < 0.9
     , text                    >= 1.2.3.0  && < 2.1
-    , time                    >= 1.5.0.1  && < 1.12
+    , time                    >= 1.5.0.1  && < 1.13
     , unordered-containers    >= 0.2.9.0  && < 0.3
     , wai                     >= 3.2.1.2  && < 3.3
 
@@ -102,7 +102,7 @@ test-suite spec
       test
   default-extensions: ConstraintKinds DataKinds DefaultSignatures DeriveFoldable DeriveFunctor DeriveGeneric DeriveTraversable FlexibleContexts FlexibleInstances FunctionalDependencies GADTs KindSignatures MultiParamTypeClasses OverloadedStrings RankNTypes ScopedTypeVariables TypeFamilies TypeOperators
   ghc-options: -Wall
-  build-tool-depends: hspec-discover:hspec-discover >=2.5.5 && <2.8
+  build-tool-depends: hspec-discover:hspec-discover >=2.5.5 && <2.10
 
   -- dependencies with bounds inherited from the library stanza
   build-depends:
@@ -123,10 +123,10 @@ test-suite spec
   -- test dependencies
   build-depends:
       servant-auth-server
-    , hspec       >= 2.5.5     && < 2.8
+    , hspec       >= 2.5.5     && < 2.10
     , QuickCheck  >= 2.11.3    && < 2.15
     , http-client >= 0.5.13.1  && < 0.8
-    , lens-aeson  >= 1.0.2     && < 1.2
+    , lens-aeson  >= 1.0.2     && < 1.3
     , warp        >= 3.2.25    && < 3.4
     , wreq        >= 0.5.2.1   && < 0.6
   other-modules:

servant-auth/servant-auth-server/src/Servant/Auth/Server/Internal/ConfigTypes.hs

@@ -33,7 +33,7 @@ data JWTSettings = JWTSettings
   -- | Algorithm used to sign JWT.
   , jwtAlg          :: Maybe Jose.Alg
   -- | Keys used to validate JWT.
-  , validationKeys  :: Jose.JWKSet
+  , validationKeys  :: IO Jose.JWKSet
   -- | An @aud@ predicate. The @aud@ is a string or URI that identifies the
   -- intended recipient of the JWT.
   , audienceMatches :: Jose.StringOrURI -> IsMatch
@@ -44,7 +44,7 @@ defaultJWTSettings :: Jose.JWK -> JWTSettings
 defaultJWTSettings k = JWTSettings
    { signingKey = k
    , jwtAlg = Nothing
-   , validationKeys = Jose.JWKSet [k]
+   , validationKeys = pure $ Jose.JWKSet [k]
    , audienceMatches = const Matches }
 
 -- | The policies to use when generating cookies.

servant-auth/servant-auth-server/src/Servant/Auth/Server/Internal/Cookie.hs

@@ -2,6 +2,7 @@
 module Servant.Auth.Server.Internal.Cookie where
 
 import           Blaze.ByteString.Builder (toByteString)
+import           Control.Monad (MonadPlus(..), guard)
 import           Control.Monad.Except
 import           Control.Monad.Reader
 import qualified Crypto.JOSE              as Jose

servant-auth/servant-auth-server/src/Servant/Auth/Server/Internal/JWT.hs

@@ -1,18 +1,14 @@
 module Servant.Auth.Server.Internal.JWT where
 
 import           Control.Lens
-import           Control.Monad.Except
+import           Control.Monad (MonadPlus(..), guard)
 import           Control.Monad.Reader
 import qualified Crypto.JOSE          as Jose
 import qualified Crypto.JWT           as Jose
-import           Data.Aeson           (FromJSON, Result (..), ToJSON, fromJSON,
-                                       toJSON)
 import           Data.ByteArray       (constEq)
 import qualified Data.ByteString      as BS
 import qualified Data.ByteString.Lazy as BSL
-import qualified Data.HashMap.Strict  as HM
 import           Data.Maybe           (fromMaybe)
-import qualified Data.Text            as T
 import           Data.Time            (UTCTime)
 import           Network.Wai          (requestHeaders)
 
@@ -42,7 +38,7 @@ jwtAuthCheck jwtSettings = do
 -- token expires.
 makeJWT :: ToJWT a
   => a -> JWTSettings -> Maybe UTCTime -> IO (Either Jose.Error BSL.ByteString)
-makeJWT v cfg expiry = runExceptT $ do
+makeJWT v cfg expiry = Jose.runJOSE $ do
   bestAlg <- Jose.bestJWSAlg $ signingKey cfg
   let alg = fromMaybe bestAlg $ jwtAlg cfg
   ejwt <- Jose.signClaims (signingKey cfg)
@@ -58,14 +54,15 @@ makeJWT v cfg expiry = runExceptT $ do
 
 verifyJWT :: FromJWT a => JWTSettings -> BS.ByteString -> IO (Maybe a)
 verifyJWT jwtCfg input = do
-  verifiedJWT <- liftIO $ runExceptT $ do
+  keys <- validationKeys jwtCfg
+  verifiedJWT <- Jose.runJOSE $ do
     unverifiedJWT <- Jose.decodeCompact (BSL.fromStrict input)
     Jose.verifyClaims
       (jwtSettingsToJwtValidationSettings jwtCfg)
-      (validationKeys jwtCfg)
+      keys
       unverifiedJWT
   return $ case verifiedJWT of
     Left (_ :: Jose.JWTError) -> Nothing
     Right v -> case decodeJWT v of
       Left _ -> Nothing
-      Right v' -> Just v'
+      Right v' -> Just v'

servant-auth/servant-auth-server/src/Servant/Auth/Server/Internal/Types.hs

@@ -2,6 +2,7 @@
 module Servant.Auth.Server.Internal.Types where
 
 import Control.Applicative
+import Control.Monad        (MonadPlus(..), ap)
 import Control.Monad.Reader
 import Control.Monad.Time
 import Data.Monoid          (Monoid (..))

servant-auth/servant-auth-server/test/Servant/Auth/ServerSpec.hs

@@ -6,13 +6,12 @@ module Servant.Auth.ServerSpec (spec) where
 #endif
 
 import           Control.Lens
-import           Control.Monad.Except                (runExceptT)
 import           Control.Monad.IO.Class              (liftIO)
 import           Crypto.JOSE                         (Alg (HS256, None), Error,
                                                       JWK, JWSHeader,
                                                       KeyMaterialGenParam (OctGenParam),
                                                       ToCompact, encodeCompact,
-                                                      genJWK, newJWSHeader)
+                                                      genJWK, newJWSHeader, runJOSE)
 import           Crypto.JWT                          (Audience (..), ClaimsSet,
                                                       NumericDate (NumericDate),
                                                       SignedJWT,
@@ -540,7 +539,7 @@ addJwtToHeader jwt = case jwt of
     $ defaults & header "Authorization" .~ ["Bearer " <> BSL.toStrict v]
 
 createJWT :: JWK -> JWSHeader () -> ClaimsSet -> IO (Either Error Crypto.JWT.SignedJWT)
-createJWT k a b = runExceptT $ signClaims k a b
+createJWT k a b = runJOSE $ signClaims k a b
 
 addJwtToCookie :: ToCompact a => CookieSettings -> Either Error a -> IO Options
 addJwtToCookie ccfg jwt = case jwt >>= (return . encodeCompact) of

servant-auth/servant-auth-swagger/servant-auth-swagger.cabal

@@ -31,15 +31,13 @@ library
   default-extensions: ConstraintKinds DataKinds DefaultSignatures DeriveFoldable DeriveFunctor DeriveGeneric DeriveTraversable FlexibleContexts FlexibleInstances FunctionalDependencies GADTs KindSignatures MultiParamTypeClasses OverloadedStrings RankNTypes ScopedTypeVariables TypeFamilies TypeOperators
   ghc-options: -Wall
   build-depends:
-      base            >= 4.10    && < 4.16
+      base            >= 4.10    && < 4.18
     , text            >= 1.2.3.0 && < 2.1
     , servant-swagger >= 1.1.5   && < 2
     , swagger2        >= 2.2.2   && < 3
     , servant         >= 0.13    && < 0.20
     , servant-auth    == 0.4.*
-    , lens            >= 4.16.1  && < 5.2
-  if impl(ghc >= 9)
-    buildable: False
+    , lens            >= 4.16.1  && < 5.3
   exposed-modules:
       Servant.Auth.Swagger
   default-language: Haskell2010
@@ -51,7 +49,7 @@ test-suite spec
       test
   default-extensions: ConstraintKinds DataKinds DefaultSignatures DeriveFoldable DeriveFunctor DeriveGeneric DeriveTraversable FlexibleContexts FlexibleInstances FunctionalDependencies GADTs KindSignatures MultiParamTypeClasses OverloadedStrings RankNTypes ScopedTypeVariables TypeFamilies TypeOperators
   ghc-options: -Wall
-  build-tool-depends: hspec-discover:hspec-discover >= 2.5.5 && <2.9
+  build-tool-depends: hspec-discover:hspec-discover >= 2.5.5 && <2.10
   -- dependencies with bounds inherited from the library stanza
   build-depends:
       base
@@ -61,13 +59,11 @@ test-suite spec
     , servant
     , servant-auth
     , lens
-  if impl(ghc >= 9)
-    buildable: False
 
   -- test dependencies
   build-depends:
       servant-auth-swagger
-    , hspec      >= 2.5.5  && < 2.9
+    , hspec      >= 2.5.5  && < 2.10
     , QuickCheck >= 2.11.3 && < 2.15
   other-modules:
       Servant.Auth.SwaggerSpec

servant-auth/servant-auth/servant-auth.cabal

@@ -33,11 +33,11 @@ library
   default-extensions: ConstraintKinds DataKinds DefaultSignatures DeriveFoldable DeriveFunctor DeriveGeneric DeriveTraversable FlexibleContexts FlexibleInstances FunctionalDependencies GADTs KindSignatures MultiParamTypeClasses OverloadedStrings RankNTypes ScopedTypeVariables TypeFamilies TypeOperators
   ghc-options: -Wall
   build-depends:
-      base                    >= 4.10     && < 4.17
+      base                    >= 4.10     && < 4.18
     , containers              >= 0.6      && < 0.7
     , aeson                   >= 1.3.1.1  && < 3
-    , jose                    >= 0.7.0.0  && < 0.10
-    , lens                    >= 4.16.1   && < 5.2
+    , jose                    >= 0.10     && < 0.11
+    , lens                    >= 4.16.1   && < 5.3
     , servant                 >= 0.15     && < 0.20
     , text                    >= 1.2.3.0  && < 2.1
     , unordered-containers    >= 0.2.9.0  && < 0.3

servant-auth/servant-auth/src/Servant/Auth.hs

@@ -27,7 +27,7 @@ instance HasLink sub => HasLink (Auth (tag :: [*]) value :> sub) where
 
 -- ** Combinators
 
--- | A JSON Web Token (JWT) in the the Authorization header:
+-- | A JSON Web Token (JWT) in the Authorization header:
 --
 --    @Authorization: Bearer \<token\>@
 --

servant-client-core/servant-client-core.cabal

@@ -50,14 +50,14 @@ library
   --
   -- note: mtl lower bound is so low because of GHC-7.8
   build-depends:
-      base                  >= 4.9      && < 4.17
+      base                  >= 4.9      && < 4.18
     , bytestring            >= 0.10.8.1 && < 0.12
     , constraints           >= 0.2      && < 0.14
     , containers            >= 0.5.7.1  && < 0.7
     , deepseq               >= 1.4.2.0  && < 1.5
     , text                  >= 1.2.3.0  && < 2.1
-    , transformers          >= 0.5.2.0  && < 0.6
-    , template-haskell      >= 2.11.1.0 && < 2.19
+    , transformers          >= 0.5.2.0  && < 0.7
+    , template-haskell      >= 2.11.1.0 && < 2.20
 
   if !impl(ghc >= 8.2)
     build-depends:
@@ -104,8 +104,8 @@ test-suite spec
   -- Additional dependencies
   build-depends:
       deepseq    >= 1.4.2.0  && < 1.5
-    , hspec      >= 2.6.0    && < 2.9
+    , hspec      >= 2.6.0    && < 2.10
     , QuickCheck >= 2.12.6.1 && < 2.15
 
   build-tool-depends:
-    hspec-discover:hspec-discover >= 2.6.0 && <2.9
+    hspec-discover:hspec-discover >= 2.6.0 && <2.10

servant-client-core/src/Servant/Client/Core/HasClient.hs

@@ -77,7 +77,7 @@ import           Servant.API
                  NoContentVerb, QueryFlag, QueryParam', QueryParams, Raw,
                  ReflectMethod (..), RemoteHost, ReqBody', SBoolI, Stream,
                  StreamBody', Summary, ToHttpApiData, ToSourceIO (..), Vault,
-                 Verb, WithNamedContext, WithStatus (..), contentType, getHeadersHList,
+                 Verb, WithNamedContext, WithResource, WithStatus (..), contentType, getHeadersHList,
                  getResponse, toEncodedUrlPiece, toUrlPiece, NamedRoutes)
 import           Servant.API.Generic
                  (GenericMode(..), ToServant, ToServantApi
@@ -208,7 +208,7 @@ instance (KnownSymbol capture, ToHttpApiData a, HasClient m api)
     clientWithRoute pm (Proxy :: Proxy api)
                     (appendToPath p req)
 
-    where p = (toUrlPiece val)
+    where p = toEncodedUrlPiece val
 
   hoistClientMonad pm _ f cl = \a ->
     hoistClientMonad pm (Proxy :: Proxy api) f (cl a)
@@ -243,7 +243,7 @@ instance (KnownSymbol capture, ToHttpApiData a, HasClient m sublayout)
     clientWithRoute pm (Proxy :: Proxy sublayout)
                     (foldl' (flip appendToPath) req ps)
 
-    where ps = map (toUrlPiece) vals
+    where ps = map toEncodedUrlPiece vals
 
   hoistClientMonad pm _ f cl = \as ->
     hoistClientMonad pm (Proxy :: Proxy sublayout) f (cl as)
@@ -740,7 +740,7 @@ instance (KnownSymbol path, HasClient m api) => HasClient m (path :> api) where
      clientWithRoute pm (Proxy :: Proxy api)
                      (appendToPath p req)
 
-    where p = pack $ symbolVal (Proxy :: Proxy path)
+    where p = toEncodedUrlPiece $ pack $ symbolVal (Proxy :: Proxy path)
 
   hoistClientMonad pm _ f cl = hoistClientMonad pm (Proxy :: Proxy api) f cl
 
@@ -776,6 +776,14 @@ instance HasClient m subapi =>
 
   hoistClientMonad pm _ f cl = hoistClientMonad pm (Proxy :: Proxy subapi) f cl
 
+instance HasClient m subapi =>
+  HasClient m (WithResource res :> subapi) where
+
+  type Client m (WithResource res :> subapi) = Client m subapi
+  clientWithRoute pm Proxy = clientWithRoute pm (Proxy :: Proxy subapi)
+
+  hoistClientMonad pm _ f cl = hoistClientMonad pm (Proxy :: Proxy subapi) f cl
+
 instance ( HasClient m api
          ) => HasClient m (AuthProtect tag :> api) where
   type Client m (AuthProtect tag :> api)
@@ -894,7 +902,7 @@ infixl 2 /:
 -- rootClient = client api
 --
 -- endpointClient :: ClientM Person
--- endpointClient = client // subApi // endpoint
+-- endpointClient = client \/\/ subApi \/\/ endpoint
 -- @
 (//) :: a -> (a -> b) -> b
 x // f = f x
@@ -927,10 +935,10 @@ x // f = f x
 -- rootClient = client api
 --
 -- hello :: String -> ClientM String
--- hello name = rootClient // hello /: name
+-- hello name = rootClient \/\/ hello \/: name
 --
 -- endpointClient :: ClientM Person
--- endpointClient = client // subApi /: "foobar123" // endpoint
+-- endpointClient = client \/\/ subApi \/: "foobar123" \/\/ endpoint
 -- @
 (/:) :: (a -> b -> c) -> b -> a -> c
 (/:) = flip

servant-client-core/src/Servant/Client/Core/Request.hs

@@ -34,6 +34,8 @@ import           Data.Bifunctor
 import           Data.Bitraversable
                  (Bitraversable (..), bifoldMapDefault, bimapDefault)
 import qualified Data.ByteString                      as BS
+import           Data.ByteString.Builder
+                 (Builder)
 import qualified Data.ByteString.Builder              as Builder
 import qualified Data.ByteString.Lazy                 as LBS
 import qualified Data.Sequence                        as Seq
@@ -112,7 +114,7 @@ instance (NFData path, NFData body) => NFData (RequestF body path) where
         rnfB Nothing        = ()
         rnfB (Just (b, mt)) = rnf b `seq` mediaTypeRnf mt
 
-type Request = RequestF RequestBody Builder.Builder
+type Request = RequestF RequestBody Builder
 
 -- | The request body. R replica of the @http-client@ @RequestBody@.
 data RequestBody
@@ -145,9 +147,10 @@ defaultRequest = Request
 
 -- | Append extra path to the request being constructed.
 --
-appendToPath :: Text -> Request -> Request
+-- Warning: This function assumes that the path fragment is already URL-encoded.
+appendToPath :: Builder -> Request -> Request
 appendToPath p req
-  = req { requestPath = requestPath req <> "/" <> toEncodedUrlPiece p }
+  = req { requestPath = requestPath req <> "/" <> p }
 
 -- | Append a query parameter to the request being constructed.
 --

servant-client-ghcjs/servant-client-ghcjs.cabal

@@ -48,7 +48,7 @@ library
     , http-media          >=0.6.2   && <0.9
     , http-types          >=0.12    && <0.13
     , monad-control       >=1.0.0.4 && <1.1
-    , mtl                 >=2.2.2   && <2.3
+    , mtl                 ^>=2.2.2  || ^>=2.3.1
     , semigroupoids       >=5.3     && <5.4
     , string-conversions  >=0.3     && <0.5
     , transformers        >=0.3     && <0.6

servant-client/servant-client.cabal

@@ -41,15 +41,15 @@ library
   -- Bundled with GHC: Lower bound to not force re-installs
   -- text and mtl are bundled starting with GHC-8.4
   build-depends:
-      base                  >= 4.9      && < 4.17
+      base                  >= 4.9      && < 4.18
     , bytestring            >= 0.10.8.1 && < 0.12
     , containers            >= 0.5.7.1  && < 0.7
     , deepseq               >= 1.4.2.0  && < 1.5
-    , mtl                   >= 2.2.2    && < 2.3
+    , mtl                   ^>= 2.2.2   || ^>= 2.3.1
     , stm                   >= 2.4.5.1  && < 2.6
     , text                  >= 1.2.3.0  && < 2.1
-    , time                  >= 1.6.0.1  && < 1.12
-    , transformers          >= 0.5.2.0  && < 0.6
+    , time                  >= 1.6.0.1  && < 1.13
+    , transformers          >= 0.5.2.0  && < 0.7
 
   if !impl(ghc >= 8.2)
     build-depends:
@@ -124,7 +124,7 @@ test-suite spec
   -- Additional dependencies
   build-depends:
       entropy           >= 0.4.1.3  && < 0.5
-    , hspec             >= 2.6.0    && < 2.9
+    , hspec             >= 2.6.0    && < 2.10
     , HUnit             >= 1.6.0.0  && < 1.7
     , network           >= 2.8.0.0  && < 3.2
     , QuickCheck        >= 2.12.6.1 && < 2.15
@@ -133,7 +133,7 @@ test-suite spec
     , tdigest           >= 0.2     && < 0.3
 
   build-tool-depends:
-    hspec-discover:hspec-discover >= 2.6.0 && < 2.9
+    hspec-discover:hspec-discover >= 2.6.0 && < 2.10
 
 test-suite readme
   type:           exitcode-stdio-1.0

servant-client/src/Servant/Client/Internal/HttpClient.hs

@@ -24,7 +24,7 @@ import           Control.Monad
 import           Control.Monad.Base
                  (MonadBase (..))
 import           Control.Monad.Catch
-                 (MonadCatch, MonadThrow)
+                 (MonadCatch, MonadThrow, MonadMask)
 import           Control.Monad.Error.Class
                  (MonadError (..))
 import           Control.Monad.IO.Class
@@ -80,7 +80,7 @@ data ClientEnv
   { manager :: Client.Manager
   , baseUrl :: BaseUrl
   , cookieJar :: Maybe (TVar Client.CookieJar)
-  , makeClientRequest :: BaseUrl -> Request -> Client.Request
+  , makeClientRequest :: BaseUrl -> Request -> IO Client.Request
   -- ^ this function can be used to customize the creation of @http-client@ requests from @servant@ requests. Default value: 'defaultMakeClientRequest'
   --   Note that:
   --      1. 'makeClientRequest' exists to allow overriding operational semantics e.g. 'responseTimeout' per request,
@@ -136,7 +136,7 @@ newtype ClientM a = ClientM
   { unClientM :: ReaderT ClientEnv (ExceptT ClientError IO) a }
   deriving ( Functor, Applicative, Monad, MonadIO, Generic
            , MonadReader ClientEnv, MonadError ClientError, MonadThrow
-           , MonadCatch)
+           , MonadCatch, MonadMask)
 
 instance MonadBase IO ClientM where
   liftBase = ClientM . liftBase
@@ -162,7 +162,7 @@ runClientM cm env = runExceptT $ flip runReaderT env $ unClientM cm
 performRequest :: Maybe [Status] -> Request -> ClientM Response
 performRequest acceptStatus req = do
   ClientEnv m burl cookieJar' createClientRequest <- ask
-  let clientRequest = createClientRequest burl req
+  clientRequest <- liftIO $ createClientRequest burl req
   request <- case cookieJar' of
     Nothing -> pure clientRequest
     Just cj -> liftIO $ do
@@ -229,8 +229,8 @@ clientResponseToResponse f r = Response
 -- | Create a @http-client@ 'Client.Request' from a @servant@ 'Request'
 --    The 'Client.host', 'Client.path' and 'Client.port' fields are extracted from the 'BaseUrl'
 --    otherwise the body, headers and query string are derived from the @servant@ 'Request'
-defaultMakeClientRequest :: BaseUrl -> Request -> Client.Request
-defaultMakeClientRequest burl r = Client.defaultRequest
+defaultMakeClientRequest :: BaseUrl -> Request -> IO Client.Request
+defaultMakeClientRequest burl r = return Client.defaultRequest
     { Client.method = requestMethod r
     , Client.host = fromString $ baseUrlHost burl
     , Client.port = baseUrlPort burl
@@ -289,7 +289,8 @@ defaultMakeClientRequest burl r = Client.defaultRequest
         Https -> True
 
     -- Query string builder which does not do any encoding
-    buildQueryString = ("?" <>) . foldl' addQueryParam mempty
+    buildQueryString [] = mempty
+    buildQueryString qps = "?" <> foldl' addQueryParam mempty qps
 
     addQueryParam qs (k, v) =
           qs <> (if BS.null qs then mempty else "&") <> urlEncode True k <> foldMap ("=" <>) v

servant-client/src/Servant/Client/Internal/HttpClient/Streaming.hs

@@ -24,7 +24,8 @@ import           Control.DeepSeq
                  (NFData, force)
 import           Control.Exception
                  (evaluate, throwIO)
-import           Control.Monad ()
+import           Control.Monad
+                 (unless)
 import           Control.Monad.Base
                  (MonadBase (..))
 import           Control.Monad.Codensity
@@ -140,7 +141,7 @@ performRequest :: Maybe [Status] -> Request -> ClientM Response
 performRequest acceptStatus req = do
     -- TODO: should use Client.withResponse here too
   ClientEnv m burl cookieJar' createClientRequest <- ask
-  let clientRequest = createClientRequest burl req
+  clientRequest <- liftIO $ createClientRequest burl req
   request <- case cookieJar' of
     Nothing -> pure clientRequest
     Just cj -> liftIO $ do
@@ -174,10 +175,21 @@ performRequest acceptStatus req = do
 -- | TODO: support UVerb ('acceptStatus' argument, like in 'performRequest' above).
 performWithStreamingRequest :: Request -> (StreamingResponse -> IO a) -> ClientM a
 performWithStreamingRequest req k = do
-  m <- asks manager
-  burl <- asks baseUrl
-  createClientRequest <- asks makeClientRequest
-  let request = createClientRequest burl req
+  ClientEnv m burl cookieJar' createClientRequest <- ask
+  clientRequest <- liftIO $ createClientRequest burl req
+  request <- case cookieJar' of
+    Nothing -> pure clientRequest
+    Just cj -> liftIO $ do
+      now <- getCurrentTime
+      atomically $ do
+        oldCookieJar <- readTVar cj
+        let (newRequest, newCookieJar) =
+              Client.insertCookiesIntoRequest
+                clientRequest
+                oldCookieJar
+                now
+        writeTVar cj newCookieJar
+        pure newRequest
   ClientM $ lift $ lift $ Codensity $ \k1 ->
       Client.withResponse request m $ \res -> do
           let status = Client.responseStatus res

servant-client/test/Servant/ClientTestUtils.hs

@@ -160,6 +160,7 @@ type Api =
                                       WithStatus 301 Text]
   :<|> "uverb-get-created" :> UVerb 'GET '[PlainText] '[WithStatus 201 Person]
   :<|> NamedRoutes RecordRoutes
+  :<|> "captureVerbatim" :> Capture "someString" Verbatim :> Get '[PlainText] Text
 
 api :: Proxy Api
 api = Proxy
@@ -214,7 +215,8 @@ getRoot
   :<|> EmptyClient
   :<|> uverbGetSuccessOrRedirect
   :<|> uverbGetCreated
-  :<|> recordRoutes = client api
+  :<|> recordRoutes
+  :<|> captureVerbatim = client api
 
 server :: Application
 server = serve api (
@@ -259,6 +261,7 @@ server = serve api (
              { something = pure ["foo", "bar", "pweet"]
              }
          }
+  :<|> pure . decodeUtf8 . unVerbatim
   )
 
 -- * api for testing failures
@@ -370,3 +373,12 @@ instance ToHttpApiData UrlEncodedByteString where
 
 instance FromHttpApiData UrlEncodedByteString where
     parseUrlPiece = pure . UrlEncodedByteString . HTTP.urlDecode True . encodeUtf8
+
+newtype Verbatim = Verbatim { unVerbatim :: ByteString }
+
+instance ToHttpApiData Verbatim where
+    toEncodedUrlPiece = byteString . unVerbatim
+    toUrlPiece = decodeUtf8 . unVerbatim
+
+instance FromHttpApiData Verbatim where
+    parseUrlPiece = pure . Verbatim . encodeUtf8

servant-client/test/Servant/SuccessSpec.hs

@@ -36,6 +36,8 @@ import           Data.Maybe
 import           Data.Monoid ()
 import           Data.Text
                  (Text)
+import           Data.Text.Encoding
+                 (encodeUtf8)
 import qualified Network.HTTP.Client                as C
 import qualified Network.HTTP.Types                 as HTTP
 import           Test.Hspec
@@ -160,7 +162,8 @@ successSpec = beforeAll (startWaiApp server) $ afterAll endWaiApp $ do
       mgr <- C.newManager C.defaultManagerSettings
       -- In proper situation, extra headers should probably be visible in API type.
       -- However, testing for response timeout is difficult, so we test with something which is easy to observe
-      let createClientRequest url r = (defaultMakeClientRequest url r) { C.requestHeaders = [("X-Added-Header", "XXX")] }
+      let createClientRequest url r = fmap (\req -> req { C.requestHeaders = [("X-Added-Header", "XXX")] })
+                                           (defaultMakeClientRequest url r)
           clientEnv = (mkClientEnv mgr baseUrl) { makeClientRequest = createClientRequest }
       res <- runClientM (getRawSuccessPassHeaders HTTP.methodGet) clientEnv
       case res of
@@ -196,3 +199,10 @@ successSpec = beforeAll (startWaiApp server) $ afterAll endWaiApp $ do
         case eitherResponse of
           Left clientError -> fail $ show clientError
           Right response -> matchUnion response `shouldBe` Just (WithStatus @201 carol)
+
+    it "encodes URL pieces following ToHttpApiData instance" $ \(_, baseUrl) -> do
+      let textOrig = "*"
+      eitherResponse <- runClient (captureVerbatim $ Verbatim $ encodeUtf8 textOrig) baseUrl
+      case eitherResponse of
+        Left clientError -> fail $ show clientError
+        Right textBack -> textBack `shouldBe` textOrig

servant-conduit/servant-conduit.cabal

@@ -31,8 +31,8 @@ library
       base          >=4.9      && <5
     , bytestring    >=0.10.8.1 && <0.12
     , conduit       >=1.3.1    && <1.4
-    , mtl           >=2.2.2    && <2.3
-    , resourcet     >=1.2.2    && <1.3
+    , mtl           ^>=2.2.2   || ^>=2.3.1
+    , resourcet     >=1.2.2    && <1.4
     , servant       >=0.15     && <0.20
     , unliftio-core >=0.1.2.0  && <0.3
   hs-source-dirs:      src

servant-docs/golden/comprehensive.md

@@ -530,6 +530,24 @@
 
 ```
 
+## GET /resource
+
+### Response:
+
+- Status code 200
+- Headers: []
+
+- Supported content types are:
+
+    - `application/json;charset=utf-8`
+    - `application/json`
+
+- Example (`application/json;charset=utf-8`, `application/json`):
+
+```javascript
+
+```
+
 ## GET /streaming
 
 ### Request:

servant-docs/servant-docs.cabal

@@ -41,7 +41,7 @@ library
   --
   -- note: mtl lower bound is so low because of GHC-7.8
   build-depends:
-      base       >= 4.9      && < 4.17
+      base       >= 4.9      && < 4.18
     , bytestring >= 0.10.8.1 && < 0.12
     , text       >= 1.2.3.0  && < 2.1
 
@@ -59,7 +59,7 @@ library
     , hashable             >= 1.2.7.0  && < 1.5
     , http-media           >= 0.7.1.3  && < 0.9
     , http-types           >= 0.12.2   && < 0.13
-    , lens                 >= 4.17     && < 5.2
+    , lens                 >= 4.17     && < 5.3
     , string-conversions   >= 0.4.0.1  && < 0.5
     , universe-base        >= 1.1.1    && < 1.2
     , unordered-containers >= 0.2.9.0  && < 0.3

servant-docs/src/Servant/Docs/Internal.hs

@@ -62,6 +62,7 @@ import           GHC.TypeLits
 import           Servant.API
 import           Servant.API.ContentTypes
 import           Servant.API.TypeLevel
+import           Servant.API.Generic
 
 import qualified Data.Universe.Helpers      as U
 
@@ -446,7 +447,7 @@ docsWith opts intros (ExtraInfo endpoints) p =
       & apiEndpoints %~ HM.unionWith (flip combineAction) endpoints
 
 
--- | Generate the docs for a given API that implements 'HasDocs' with with any
+-- | Generate the docs for a given API that implements 'HasDocs' with any
 -- number of introduction(s)
 docsWithIntros :: HasDocs api => [DocIntro] -> Proxy api -> API
 docsWithIntros intros = docsWith defaultDocOptions intros mempty
@@ -1143,6 +1144,9 @@ instance HasDocs api => HasDocs (Vault :> api) where
 instance HasDocs api => HasDocs (WithNamedContext name context api) where
   docsFor Proxy = docsFor (Proxy :: Proxy api)
 
+instance HasDocs api => HasDocs (WithResource res :> api) where
+  docsFor Proxy = docsFor (Proxy :: Proxy api)
+
 instance (ToAuthInfo (BasicAuth realm usr), HasDocs api) => HasDocs (BasicAuth realm usr :> api) where
   docsFor Proxy (endpoint, action) =
     docsFor (Proxy :: Proxy api) (endpoint, action')
@@ -1150,6 +1154,9 @@ instance (ToAuthInfo (BasicAuth realm usr), HasDocs api) => HasDocs (BasicAuth r
         authProxy = Proxy :: Proxy (BasicAuth realm usr)
         action' = over authInfo (|> toAuthInfo authProxy) action
 
+instance HasDocs (ToServantApi api) => HasDocs (NamedRoutes api) where
+  docsFor Proxy = docsFor (Proxy :: Proxy (ToServantApi api))
+
 -- ToSample instances for simple types
 instance ToSample NoContent
 instance ToSample Bool

servant-foreign/servant-foreign.cabal

@@ -41,7 +41,7 @@ library
   --
   -- note: mtl lower bound is so low because of GHC-7.8
   build-depends:
-      base        >= 4.9     && < 4.17
+      base        >= 4.9     && < 4.18
     , text        >= 1.2.3.0 && < 2.1
 
   -- Servant dependencies
@@ -52,7 +52,7 @@ library
   -- Here can be exceptions if we really need features from the newer versions.
   build-depends:
       base-compat >= 0.10.5  && < 0.13
-    , lens        >= 4.17    && < 5.2
+    , lens        >= 4.17    && < 5.3
     , http-types  >= 0.12.2  && < 0.13
 
   hs-source-dirs:      src
@@ -74,7 +74,7 @@ test-suite spec
 
   -- Additional dependencies
   build-depends:
-    hspec >= 2.6.0 && <2.9
+    hspec >= 2.6.0 && <2.10
   build-tool-depends:
-    hspec-discover:hspec-discover >=2.6.0 && <2.9
+    hspec-discover:hspec-discover >=2.6.0 && <2.10
   default-language:  Haskell2010

servant-foreign/src/Servant/Foreign/Internal.hs

@@ -487,6 +487,13 @@ instance HasForeign lang ftype api =>
 
   foreignFor lang ftype Proxy = foreignFor lang ftype (Proxy :: Proxy api)
 
+instance HasForeign lang ftype api =>
+  HasForeign lang ftype (WithResource res :> api) where
+
+  type Foreign ftype (WithResource res :> api) = Foreign ftype api
+
+  foreignFor lang ftype Proxy = foreignFor lang ftype (Proxy :: Proxy api)
+
 instance HasForeign lang ftype api
   => HasForeign lang ftype (HttpVersion :> api) where
   type Foreign ftype (HttpVersion :> api) = Foreign ftype api

servant-http-streams/servant-http-streams.cabal

@@ -38,14 +38,14 @@ library
   -- Bundled with GHC: Lower bound to not force re-installs
   -- text and mtl are bundled starting with GHC-8.4
   build-depends:
-      base                  >= 4.9      && < 4.17
+      base                  >= 4.9      && < 4.18
     , bytestring            >= 0.10.8.1 && < 0.12
     , containers            >= 0.5.7.1  && < 0.7
     , deepseq               >= 1.4.2.0  && < 1.5
-    , mtl                   >= 2.2.2    && < 2.3
+    , mtl                   ^>= 2.2.2   || ^>= 2.3.1
     , text                  >= 1.2.3.0  && < 2.1
-    , time                  >= 1.6.0.1  && < 1.12
-    , transformers          >= 0.5.2.0  && < 0.6
+    , time                  >= 1.6.0.1  && < 1.13
+    , transformers          >= 0.5.2.0  && < 0.7
 
   if !impl(ghc >= 8.2)
     build-depends:
@@ -112,7 +112,7 @@ test-suite spec
   -- Additional dependencies
   build-depends:
       entropy           >= 0.4.1.3  && < 0.5
-    , hspec             >= 2.6.0    && < 2.9
+    , hspec             >= 2.6.0    && < 2.10
     , HUnit             >= 1.6.0.0  && < 1.7
     , network           >= 2.8.0.0  && < 3.2
     , QuickCheck        >= 2.12.6.1 && < 2.15
@@ -121,7 +121,7 @@ test-suite spec
     , tdigest           >= 0.2     && < 0.3
 
   build-tool-depends:
-    hspec-discover:hspec-discover >= 2.6.0 && < 2.9
+    hspec-discover:hspec-discover >= 2.6.0 && < 2.10
 
 test-suite readme
   type:           exitcode-stdio-1.0

servant-machines/servant-machines.cabal

@@ -31,7 +31,7 @@ library
       base          >=4.9      && <5
     , bytestring    >=0.10.8.1 && <0.12
     , machines      >=0.6.4    && <0.8
-    , mtl           >=2.2.2    && <2.3
+    , mtl           ^>=2.2.2   || ^>=2.3.1
     , servant       >=0.15     && <0.20
   hs-source-dirs:      src
   default-language:    Haskell2010

servant-pipes/servant-pipes.cabal

@@ -32,7 +32,7 @@ library
     , bytestring    >=0.10.8.1 && <0.12
     , pipes         >=4.3.9    && <4.4
     , pipes-safe    >=2.3.1    && <2.4
-    , mtl           >=2.2.2    && <2.3
+    , mtl           ^>=2.2.2   || ^>=2.3.1
     , monad-control >=1.0.2.3  && <1.1
     , servant       >=0.15     && <0.20
   hs-source-dirs:      src

servant-server/CHANGELOG.md

@@ -3,11 +3,17 @@
 
 Package versions follow the [Package Versioning Policy](https://pvp.haskell.org/): in A.B.C, bumps to either A or B represent major versions.
 
+0.19.2
+------
+
+Compatibility with GHC 9.4, see [PR #1592](https://github.com/haskell-servant/servant/pull/1592).
+
 0.19.1
 ------
 
 - Add `MonadFail` instance for `Handler` wrt [#1545](https://github.com/haskell-servant/servant/issues/1545)
 - Support GHC 9.2 [#1525](https://github.com/haskell-servant/servant/issues/1525)
+- Add capture hints in `Router` type for debug and display purposes [PR #1556] (https://github.com/haskell-servant/servant/pull/1556)
 
 0.19
 ----

servant-server/servant-server.cabal

@@ -1,6 +1,6 @@
 cabal-version:       2.2
 name:                servant-server
-version:             0.19.1
+version:             0.19.2
 
 synopsis:            A family of combinators for defining webservices APIs and serving them
 category:            Servant, Web
@@ -23,7 +23,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 copyright:           2014-2016 Zalora South East Asia Pte Ltd, 2016-2019 Servant Contributors
 build-type:          Simple
-tested-with: GHC ==8.6.5 || ==8.8.4 || ==8.10.2 || ==9.0.1
+tested-with: GHC ==8.6.5 || ==8.8.4 || ==8.10.7 || ==9.0.2 || ==9.2.4 || ==9.4.3
 
 extra-source-files:
   CHANGELOG.md
@@ -60,20 +60,20 @@ library
   -- Bundled with GHC: Lower bound to not force re-installs
   -- text and mtl are bundled starting with GHC-8.4
   build-depends:
-      base                >= 4.9      && < 4.17
+      base                >= 4.9      && < 4.18
     , bytestring          >= 0.10.8.1 && < 0.12
     , constraints         >= 0.2      && < 0.14
     , containers          >= 0.5.7.1  && < 0.7
-    , mtl                 >= 2.2.2    && < 2.3
+    , mtl                 ^>= 2.2.2   || ^>= 2.3.1
     , text                >= 1.2.3.0  && < 2.1
-    , transformers        >= 0.5.2.0  && < 0.6
+    , transformers        >= 0.5.2.0  && < 0.7
     , filepath            >= 1.4.1.1  && < 1.5
 
   -- Servant dependencies
   -- strict dependency as we re-export 'servant' things.
   build-depends:
-      servant             >= 0.19
-    , http-api-data       >= 0.4.1    && < 0.4.4
+      servant             >= 0.19     && < 0.20
+    , http-api-data       >= 0.4.1    && < 0.5.1
 
   -- Other dependencies: Lower bound around what is in the latest Stackage LTS.
   -- Here can be exceptions if we really need features from the newer versions.
@@ -88,10 +88,10 @@ library
     , network             >= 2.8      && < 3.2
     , sop-core            >= 0.4.0.0  && < 0.6
     , string-conversions  >= 0.4.0.1  && < 0.5
-    , resourcet           >= 1.2.2    && < 1.3
+    , resourcet           >= 1.2.2    && < 1.4
     , tagged              >= 0.8.6    && < 0.9
     , transformers-base   >= 0.4.5.2  && < 0.5
-    , wai                 >= 3.2.1.2  && < 3.3
+    , wai                 >= 3.2.2.1  && < 3.3
     , wai-app-static      >= 3.1.6.2  && < 3.2
     , word8               >= 0.1.3    && < 0.2
 
@@ -159,7 +159,7 @@ test-suite spec
   build-depends:
       aeson                >= 1.4.1.0  && < 3
     , directory            >= 1.3.0.0  && < 1.4
-    , hspec                >= 2.6.0    && < 2.9
+    , hspec                >= 2.6.0    && < 2.10
     , hspec-wai            >= 0.10.1   && < 0.12
     , QuickCheck           >= 2.12.6.1 && < 2.15
     , should-not-typecheck >= 2.1.0    && < 2.2
@@ -167,4 +167,4 @@ test-suite spec
     , wai-extra            >= 3.0.24.3 && < 3.2
 
   build-tool-depends:
-    hspec-discover:hspec-discover >= 2.6.0 && <2.9
+    hspec-discover:hspec-discover >= 2.6.0 && <2.10

servant-server/src/Servant/Server.hs

@@ -235,7 +235,7 @@ hoistServer p = hoistServerWithContext p (Proxy :: Proxy '[])
 -- > │  └─ e/
 -- > │     └─•
 -- > ├─ b/
--- > │  └─ <capture>/
+-- > │  └─ <x::Int>/
 -- > │     ├─•
 -- > │     ┆
 -- > │     └─•
@@ -252,7 +252,8 @@ hoistServer p = hoistServerWithContext p (Proxy :: Proxy '[])
 --
 -- [@─•@] Leaves reflect endpoints.
 --
--- [@\<capture\>/@] This is a delayed capture of a path component.
+-- [@\<x::Int\>/@] This is a delayed capture of a single
+-- path component named @x@, of expected type @Int@.
 --
 -- [@\<raw\>@] This is a part of the API we do not know anything about.
 --

servant-server/src/Servant/Server/Experimental/Auth.hs

@@ -1,5 +1,6 @@
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 {-# LANGUAGE DeriveDataTypeable    #-}
+{-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE DeriveGeneric         #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE FlexibleInstances     #-}
@@ -44,7 +45,7 @@ type family AuthServerData a :: *
 -- NOTE: THIS API IS EXPERIMENTAL AND SUBJECT TO CHANGE
 newtype AuthHandler r usr = AuthHandler
   { unAuthHandler :: r -> Handler usr }
-  deriving (Generic, Typeable)
+  deriving (Functor, Generic, Typeable)
 
 -- | NOTE: THIS API IS EXPERIMENTAL AND SUBJECT TO CHANGE
 mkAuthHandler :: (r -> Handler usr) -> AuthHandler r usr

servant-server/src/Servant/Server/Internal.hs

@@ -1,5 +1,6 @@
 {-# LANGUAGE AllowAmbiguousTypes   #-}
 {-# LANGUAGE ConstraintKinds       #-}
+{-# LANGUAGE CPP                   #-}
 {-# LANGUAGE DataKinds             #-}
 {-# LANGUAGE DeriveDataTypeable    #-}
 {-# LANGUAGE FlexibleContexts      #-}
@@ -34,9 +35,10 @@ module Servant.Server.Internal
 import           Control.Monad
                  (join, when)
 import           Control.Monad.Trans
-                 (liftIO)
+                 (liftIO, lift)
 import           Control.Monad.Trans.Resource
-                 (runResourceT)
+                 (runResourceT, ReleaseKey)
+import           Data.Acquire
 import qualified Data.ByteString                            as B
 import qualified Data.ByteString.Builder                    as BB
 import qualified Data.ByteString.Char8                      as BC8
@@ -76,7 +78,7 @@ import           Servant.API
                  QueryParam', QueryParams, Raw, ReflectMethod (reflectMethod),
                  RemoteHost, ReqBody', SBool (..), SBoolI (..), SourceIO,
                  Stream, StreamBody', Summary, ToSourceIO (..), Vault, Verb,
-                 WithNamedContext, NamedRoutes)
+                 WithNamedContext, WithResource, NamedRoutes)
 import           Servant.API.Generic (GenericMode(..), ToServant, ToServantApi, GServantProduct, toServant, fromServant)
 import           Servant.API.ContentTypes
                  (AcceptHeader (..), AllCTRender (..), AllCTUnrender (..),
@@ -94,6 +96,8 @@ import           Servant.API.TypeErrors
 import           Web.HttpApiData
                  (FromHttpApiData, parseHeader, parseQueryParam, parseUrlPiece,
                  parseUrlPieces)
+import           Data.Kind
+                 (Type)
 
 import           Servant.Server.Internal.BasicAuth
 import           Servant.Server.Internal.Context
@@ -112,6 +116,10 @@ import           Servant.API.TypeLevel
                  (AtLeastOneFragment, FragmentUnique)
 
 class HasServer api context where
+  -- | The type of a server for this API, given a monad to run effects in.
+  --
+  -- Note that the result kind is @*@, so it is /not/ a monad transformer, unlike
+  -- what the @T@ in the name might suggest.
   type ServerT api (m :: * -> *) :: *
 
   route ::
@@ -173,7 +181,7 @@ instance (HasServer a context, HasServer b context) => HasServer (a :<|> b) cont
 -- > server = getBook
 -- >   where getBook :: Text -> Handler Book
 -- >         getBook isbn = ...
-instance (KnownSymbol capture, FromHttpApiData a
+instance (KnownSymbol capture, FromHttpApiData a, Typeable a
          , HasServer api context, SBoolI (FoldLenient mods)
          , HasContextEntry (MkContextWithErrorFormatter context) ErrorFormatters
          )
@@ -185,7 +193,7 @@ instance (KnownSymbol capture, FromHttpApiData a
   hoistServerWithContext _ pc nt s = hoistServerWithContext (Proxy :: Proxy api) pc nt . s
 
   route Proxy context d =
-    CaptureRouter $
+    CaptureRouter [hint] $
         route (Proxy :: Proxy api)
               context
               (addCapture d $ \ txt -> withRequest $ \ request ->
@@ -197,6 +205,7 @@ instance (KnownSymbol capture, FromHttpApiData a
     where
       rep = typeRep (Proxy :: Proxy Capture')
       formatError = urlParseErrorFormatter $ getContextEntry (mkContextWithErrorFormatter context)
+      hint = CaptureHint (T.pack $ symbolVal $ Proxy @capture) (typeRep (Proxy :: Proxy a))
 
 -- | If you use 'CaptureAll' in one of the endpoints for your API,
 -- this automatically requires your server-side handler to be a
@@ -215,7 +224,7 @@ instance (KnownSymbol capture, FromHttpApiData a
 -- > server = getSourceFile
 -- >   where getSourceFile :: [Text] -> Handler Book
 -- >         getSourceFile pathSegments = ...
-instance (KnownSymbol capture, FromHttpApiData a
+instance (KnownSymbol capture, FromHttpApiData a, Typeable a
          , HasServer api context
          , HasContextEntry (MkContextWithErrorFormatter context) ErrorFormatters
          )
@@ -227,7 +236,7 @@ instance (KnownSymbol capture, FromHttpApiData a
   hoistServerWithContext _ pc nt s = hoistServerWithContext (Proxy :: Proxy api) pc nt . s
 
   route Proxy context d =
-    CaptureAllRouter $
+    CaptureAllRouter [hint] $
         route (Proxy :: Proxy api)
               context
               (addCapture d $ \ txts -> withRequest $ \ request ->
@@ -238,6 +247,43 @@ instance (KnownSymbol capture, FromHttpApiData a
     where
       rep = typeRep (Proxy :: Proxy CaptureAll)
       formatError = urlParseErrorFormatter $ getContextEntry (mkContextWithErrorFormatter context)
+      hint = CaptureHint (T.pack $ symbolVal $ Proxy @capture) (typeRep (Proxy :: Proxy [a]))
+
+-- | If you use 'WithResource' in one of the endpoints for your API Servant
+-- will provide the handler for this endpoint an argument of the specified type.
+-- The lifespan of this resource will be automatically managed by Servant. This
+-- resource will be created before the handler starts and it will be destoyed
+-- after it ends. A new resource is created for each request to the endpoint.
+
+-- The creation and destruction are done using a 'Data.Acquire.Acquire'
+-- provided via server 'Context'.
+--
+-- Example
+--
+-- > type MyApi = WithResource Handle :> "writeToFile" :> Post '[JSON] NoContent
+-- >
+-- > server :: Server MyApi
+-- > server = writeToFile
+-- >   where writeToFile :: (ReleaseKey, Handle) -> Handler NoContent
+-- >         writeToFile (_, h) = hPutStrLn h "message"
+--
+-- In addition to the resource, the handler will also receive a 'ReleaseKey'
+-- which can be used to deallocate the resource before the end of the request
+-- if desired.
+
+instance (HasServer api ctx, HasContextEntry ctx (Acquire a))
+      => HasServer (WithResource a :> api) ctx where
+
+  type ServerT (WithResource a :> api) m = (ReleaseKey, a) -> ServerT api m
+
+  hoistServerWithContext _ pc nt s = hoistServerWithContext (Proxy @api) pc nt . s
+
+  route Proxy context d = route (Proxy @api) context (d `addParameterCheck` allocateResource)
+    where
+      allocateResource :: DelayedIO (ReleaseKey, a)
+      allocateResource = DelayedIO $ lift $ allocateAcquire (getContextEntry context)
+
+
 
 allowedMethodHead :: Method -> Request -> Bool
 allowedMethodHead method request = method == methodGet && requestMethod request == methodHead
@@ -819,7 +865,11 @@ instance (HasContextEntry context (NamedContext name subContext), HasServer subA
 -------------------------------------------------------------------------------
 
 -- Erroring instance for 'HasServer' when a combinator is not fully applied
-instance TypeError (PartialApplication HasServer arr) => HasServer ((arr :: a -> b) :> sub) context
+instance TypeError (PartialApplication 
+#if __GLASGOW_HASKELL__ >= 904
+                    @(Type -> [Type] -> Constraint) 
+#endif
+                    HasServer arr) => HasServer ((arr :: a -> b) :> sub) context
   where
     type ServerT (arr :> sub) _ = TypeError (PartialApplication (HasServer :: * -> [*] -> Constraint) arr)
     route = error "unreachable"
@@ -863,7 +913,11 @@ type HasServerArrowTypeError a b =
 -- XXX: This omits the @context@ parameter, e.g.:
 --
 -- "There is no instance for HasServer (Bool :> …)". Do we care ?
-instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub HasServer ty) => HasServer (ty :> sub) context
+instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub 
+#if __GLASGOW_HASKELL__ >= 904
+                                         @(Type -> [Type] -> Constraint) 
+#endif
+                                         HasServer ty) => HasServer (ty :> sub) context
 
 instance {-# OVERLAPPABLE #-} TypeError (NoInstanceFor (HasServer api context)) => HasServer api context
 

servant-server/src/Servant/Server/Internal/Router.hs

@@ -9,12 +9,16 @@ import           Prelude.Compat
 
 import           Data.Function
                  (on)
+import           Data.List
+                 (nub)
 import           Data.Map
                  (Map)
 import qualified Data.Map                                   as M
 import           Data.Text
                  (Text)
 import qualified Data.Text                                  as T
+import           Data.Typeable
+                 (TypeRep)
 import           Network.Wai
                  (Response, pathInfo)
 import           Servant.Server.Internal.ErrorFormatter
@@ -24,6 +28,21 @@ import           Servant.Server.Internal.ServerError
 
 type Router env = Router' env RoutingApplication
 
+-- | Holds information about pieces of url that are captured as variables.
+data CaptureHint = CaptureHint
+  { captureName :: Text
+  -- ^ Holds the name of the captured variable
+  , captureType :: TypeRep
+  -- ^ Holds the type of the captured variable
+  }
+  deriving (Show, Eq)
+
+toCaptureTag :: CaptureHint -> Text
+toCaptureTag hint = captureName hint <> "::" <> (T.pack . show) (captureType hint)
+
+toCaptureTags :: [CaptureHint] -> Text
+toCaptureTags hints = "<" <> T.intercalate "|" (map toCaptureTag hints) <> ">"
+
 -- | Internal representation of a router.
 --
 -- The first argument describes an environment type that is
@@ -36,12 +55,23 @@ data Router' env a =
       -- ^ the map contains routers for subpaths (first path component used
       --   for lookup and removed afterwards), the list contains handlers
       --   for the empty path, to be tried in order
-  | CaptureRouter (Router' (Text, env) a)
+  | CaptureRouter [CaptureHint] (Router' (Text, env) a)
       -- ^ first path component is passed to the child router in its
-      --   environment and removed afterwards
-  | CaptureAllRouter (Router' ([Text], env) a)
+      --   environment and removed afterwards.
+      --   The first argument is a list of hints for all variables that can be
+      --   captured by the router. The fact that it is a list is counter-intuitive,
+      --   because the 'Capture' combinator only allows to capture a single varible,
+      --   with a single name and a single type. However, the 'choice' smart
+      --   constructor may merge two 'Capture' combinators with different hints, thus
+      --   forcing the type to be '[CaptureHint]'.
+      --   Because 'CaptureRouter' is built from a 'Capture' combinator, the list of
+      --   hints should always be non-empty.
+  | CaptureAllRouter [CaptureHint] (Router' ([Text], env) a)
       -- ^ all path components are passed to the child router in its
       --   environment and are removed afterwards
+      --   The first argument is a hint for the list of variables that can be
+      --   captured by the router. Note that the 'captureType' field of the hint
+      --   should always be '[a]' for some 'a'.
   | RawRouter     (env -> a)
       -- ^ to be used for routes we do not know anything about
   | Choice        (Router' env a) (Router' env a)
@@ -69,8 +99,8 @@ leafRouter l = StaticRouter M.empty [l]
 choice :: Router' env a -> Router' env a -> Router' env a
 choice (StaticRouter table1 ls1) (StaticRouter table2 ls2) =
   StaticRouter (M.unionWith choice table1 table2) (ls1 ++ ls2)
-choice (CaptureRouter router1)   (CaptureRouter router2)   =
-  CaptureRouter (choice router1 router2)
+choice (CaptureRouter hints1 router1)   (CaptureRouter hints2 router2)   =
+  CaptureRouter (nub $ hints1 ++ hints2) (choice router1 router2)
 choice router1 (Choice router2 router3) = Choice (choice router1 router2) router3
 choice router1 router2 = Choice router1 router2
 
@@ -84,7 +114,11 @@ choice router1 router2 = Choice router1 router2
 --
 data RouterStructure =
     StaticRouterStructure  (Map Text RouterStructure) Int
-  | CaptureRouterStructure RouterStructure
+  | CaptureRouterStructure [CaptureHint] RouterStructure
+  -- ^ The first argument holds information about variables
+  -- that are captured by the router. There may be several hints
+  -- if several routers have been aggregated by the 'choice'
+  -- smart constructor.
   | RawRouterStructure
   | ChoiceStructure        RouterStructure RouterStructure
   deriving (Eq, Show)
@@ -98,11 +132,11 @@ data RouterStructure =
 routerStructure :: Router' env a -> RouterStructure
 routerStructure (StaticRouter m ls) =
   StaticRouterStructure (fmap routerStructure m) (length ls)
-routerStructure (CaptureRouter router) =
-  CaptureRouterStructure $
+routerStructure (CaptureRouter hints router) =
+  CaptureRouterStructure hints $
     routerStructure router
-routerStructure (CaptureAllRouter router) =
-  CaptureRouterStructure $
+routerStructure (CaptureAllRouter hints router) =
+  CaptureRouterStructure hints $
     routerStructure router
 routerStructure (RawRouter _) =
   RawRouterStructure
@@ -114,8 +148,8 @@ routerStructure (Choice r1 r2) =
 -- | Compare the structure of two routers.
 --
 sameStructure :: Router' env a -> Router' env b -> Bool
-sameStructure r1 r2 =
-  routerStructure r1 == routerStructure r2
+sameStructure router1 router2 =
+    routerStructure router1 == routerStructure router2
 
 -- | Provide a textual representation of the
 -- structure of a router.
@@ -126,7 +160,8 @@ routerLayout router =
   where
     mkRouterLayout :: Bool -> RouterStructure -> [Text]
     mkRouterLayout c (StaticRouterStructure m n) = mkSubTrees c (M.toList m) n
-    mkRouterLayout c (CaptureRouterStructure r)  = mkSubTree c "<capture>" (mkRouterLayout False r)
+    mkRouterLayout c (CaptureRouterStructure hints r) =
+      mkSubTree c (toCaptureTags hints) (mkRouterLayout False r)
     mkRouterLayout c  RawRouterStructure         =
       if c then ["├─ <raw>"] else ["└─ <raw>"]
     mkRouterLayout c (ChoiceStructure r1 r2)     =
@@ -169,7 +204,7 @@ runRouterEnv fmt router env request respond  =
           -> let request' = request { pathInfo = rest }
              in  runRouterEnv fmt router' env request' respond
         _ -> respond $ Fail $ fmt request
-    CaptureRouter router' ->
+    CaptureRouter _ router' ->
       case pathInfo request of
         []   -> respond $ Fail $ fmt request
         -- This case is to handle trailing slashes.
@@ -177,7 +212,7 @@ runRouterEnv fmt router env request respond  =
         first : rest
           -> let request' = request { pathInfo = rest }
              in  runRouterEnv fmt router' (first, env) request' respond
-    CaptureAllRouter router' ->
+    CaptureAllRouter _ router' ->
       let segments = pathInfo request
           request' = request { pathInfo = [] }
       in runRouterEnv fmt router' (segments, env) request' respond

servant-server/test/Servant/Server/RouterSpec.hs

@@ -9,7 +9,9 @@ import           Control.Monad
 import           Data.Proxy
                  (Proxy (..))
 import           Data.Text
-                 (unpack)
+                 (Text, unpack)
+import           Data.Typeable
+                 (typeRep)
 import           Network.HTTP.Types
                  (Status (..))
 import           Network.Wai
@@ -27,6 +29,7 @@ spec :: Spec
 spec = describe "Servant.Server.Internal.Router" $ do
   routerSpec
   distributivitySpec
+  serverLayoutSpec
 
 routerSpec :: Spec
 routerSpec = do
@@ -51,7 +54,7 @@ routerSpec = do
         toApp = toApplication . runRouter (const err404)
 
         cap :: Router ()
-        cap = CaptureRouter $
+        cap = CaptureRouter [hint] $
           let delayed = addCapture (emptyDelayed $ Route pure) (const $ delayedFail err400)
           in leafRouter
              $ \env req res ->
@@ -59,6 +62,9 @@ routerSpec = do
                  . const
                  $ Route success
 
+        hint :: CaptureHint
+        hint = CaptureHint "anything" $ typeRep (Proxy :: Proxy ())
+
         router :: Router ()
         router = leafRouter (\_ _ res -> res $ Route success)
           `Choice` cap
@@ -98,12 +104,30 @@ distributivitySpec =
     it "properly handles mixing static paths at different levels" $ do
       level `shouldHaveSameStructureAs` levelRef
 
+serverLayoutSpec :: Spec
+serverLayoutSpec =
+  describe "serverLayout" $ do
+    it "correctly represents the example API" $ do
+      exampleLayout `shouldHaveLayout` expectedExampleLayout
+    it "aggregates capture hints when different" $ do
+      captureDifferentTypes `shouldHaveLayout` expectedCaptureDifferentTypes
+    it "nubs capture hints when equal" $ do
+      captureSameType `shouldHaveLayout` expectedCaptureSameType
+    it "properly displays CaptureAll hints" $ do
+      captureAllLayout `shouldHaveLayout` expectedCaptureAllLayout
+
 shouldHaveSameStructureAs ::
   (HasServer api1 '[], HasServer api2 '[]) => Proxy api1 -> Proxy api2 -> Expectation
 shouldHaveSameStructureAs p1 p2 =
   unless (sameStructure (makeTrivialRouter p1) (makeTrivialRouter p2)) $
     expectationFailure ("expected:\n" ++ unpack (layout p2) ++ "\nbut got:\n" ++ unpack (layout p1))
 
+shouldHaveLayout ::
+  (HasServer api '[]) => Proxy api -> Text -> Expectation
+shouldHaveLayout p l =
+  unless (routerLayout (makeTrivialRouter p) == l) $
+    expectationFailure ("expected:\n" ++ unpack l ++ "\nbut got:\n" ++ unpack (layout p))
+
 makeTrivialRouter :: (HasServer layout '[]) => Proxy layout -> Router ()
 makeTrivialRouter p =
   route p EmptyContext (emptyDelayed (FailFatal err501))
@@ -144,12 +168,12 @@ staticRef = Proxy
 -- structure:
 
 type Dynamic =
-       "a" :> Capture "foo" Int  :> "b" :> End
-  :<|> "a" :> Capture "bar" Bool :> "c" :> End
-  :<|> "a" :> Capture "baz" Char :> "d" :> End
+       "a" :> Capture "foo" Int :> "b" :> End
+  :<|> "a" :> Capture "foo" Int :> "c" :> End
+  :<|> "a" :> Capture "foo" Int :> "d" :> End
 
 type DynamicRef =
-  "a" :> Capture "anything" () :>
+  "a" :> Capture "foo" Int :>
     ("b" :> End :<|> "c" :> End :<|> "d" :> End)
 
 dynamic :: Proxy Dynamic
@@ -339,3 +363,100 @@ level = Proxy
 
 levelRef :: Proxy LevelRef
 levelRef = Proxy
+
+-- The example API for the 'layout' function.
+-- Should get factorized by the 'choice' smart constructor.
+type ExampleLayout =
+       "a" :> "d" :> Get '[JSON] NoContent
+  :<|> "b" :> Capture "x" Int :> Get '[JSON] Bool
+  :<|> "c" :> Put '[JSON] Bool
+  :<|> "a" :> "e" :> Get '[JSON] Int
+  :<|> "b" :> Capture "x" Int :> Put '[JSON] Bool
+  :<|> Raw
+
+exampleLayout :: Proxy ExampleLayout
+exampleLayout = Proxy
+
+-- The expected representation of the example API layout
+--
+expectedExampleLayout :: Text
+expectedExampleLayout =
+  "/\n\
+  \├─ a/\n\
+  \│  ├─ d/\n\
+  \│  │  └─•\n\
+  \│  └─ e/\n\
+  \│     └─•\n\
+  \├─ b/\n\
+  \│  └─ <x::Int>/\n\
+  \│     ├─•\n\
+  \│     ┆\n\
+  \│     └─•\n\
+  \├─ c/\n\
+  \│  └─•\n\
+  \┆\n\
+  \└─ <raw>\n"
+
+-- A capture API with all capture types being the same
+--
+type CaptureSameType =
+       "a" :> Capture "foo" Int :> "b" :> End
+  :<|> "a" :> Capture "foo" Int :> "c" :> End
+  :<|> "a" :> Capture "foo" Int :> "d" :> End
+
+captureSameType :: Proxy CaptureSameType
+captureSameType = Proxy
+
+-- The expected representation of the CaptureSameType API layout.
+--
+expectedCaptureSameType :: Text
+expectedCaptureSameType =
+  "/\n\
+  \└─ a/\n\
+  \   └─ <foo::Int>/\n\
+  \      ├─ b/\n\
+  \      │  └─•\n\
+  \      ├─ c/\n\
+  \      │  └─•\n\
+  \      └─ d/\n\
+  \         └─•\n"
+
+-- A capture API capturing different types
+--
+type CaptureDifferentTypes =
+       "a" :> Capture "foo" Int :> "b" :> End
+  :<|> "a" :> Capture "bar" Bool :> "c" :> End
+  :<|> "a" :> Capture "baz" Char :> "d" :> End
+
+captureDifferentTypes :: Proxy CaptureDifferentTypes
+captureDifferentTypes = Proxy
+
+-- The expected representation of the CaptureDifferentTypes API layout.
+--
+expectedCaptureDifferentTypes :: Text
+expectedCaptureDifferentTypes =
+  "/\n\
+  \└─ a/\n\
+  \   └─ <foo::Int|bar::Bool|baz::Char>/\n\
+  \      ├─ b/\n\
+  \      │  └─•\n\
+  \      ├─ c/\n\
+  \      │  └─•\n\
+  \      └─ d/\n\
+  \         └─•\n"
+
+-- An API with a CaptureAll part
+
+type CaptureAllLayout = "a" :> CaptureAll "foos" Int :> End
+
+captureAllLayout :: Proxy CaptureAllLayout
+captureAllLayout = Proxy
+
+-- The expected representation of the CaptureAllLayout API.
+--
+expectedCaptureAllLayout :: Text
+expectedCaptureAllLayout =
+  "/\n\
+  \└─ a/\n\
+  \   └─ <foos::[Int]>/\n\
+  \      └─•\n"

servant-server/test/Servant/ServerSpec.hs

@@ -21,6 +21,8 @@ import           Control.Monad.Error.Class
                  (MonadError (..))
 import           Data.Aeson
                  (FromJSON, ToJSON, decode', encode)
+import           Data.Acquire
+                 (Acquire, mkAcquire)
 import qualified Data.ByteString                   as BS
 import qualified Data.ByteString.Base64            as Base64
 import           Data.Char
@@ -81,8 +83,11 @@ import           Servant.Server.Internal.Context
 -- This declaration simply checks that all instances are in place.
 _ = serveWithContext comprehensiveAPI comprehensiveApiContext
 
-comprehensiveApiContext :: Context '[NamedContext "foo" '[]]
-comprehensiveApiContext = NamedContext EmptyContext :. EmptyContext
+comprehensiveApiContext :: Context '[NamedContext "foo" '[], Acquire Int]
+comprehensiveApiContext =
+  NamedContext EmptyContext :.
+  mkAcquire (pure 10) (\_ -> pure ()) :.
+  EmptyContext
 
 -- * Specs
 

servant-swagger/servant-swagger.cabal

@@ -77,7 +77,7 @@ library
                      , http-media                >=0.7.1.3  && <0.9
                      , insert-ordered-containers >=0.2.1.0  && <0.3
                      , lens                      >=4.17     && <6
-                     , servant                   >=0.18.1   && <0.20
+                     , servant                   >=0.18.2   && <0.20
                      , singleton-bool            >=0.1.4    && <0.2
                      , swagger2                  >=2.3.0.1  && <3
                      , text                      >=1.2.3.0  && <2.1
@@ -106,14 +106,14 @@ test-suite spec
   type:             exitcode-stdio-1.0
   hs-source-dirs:   test
   main-is:          Spec.hs
-  build-tool-depends: hspec-discover:hspec-discover >=2.6.0 && <2.8
+  build-tool-depends: hspec-discover:hspec-discover >=2.6.0 && <2.11
   build-depends:    base
                   , base-compat
                   , aeson >=1.4.2.0 && <3
-                  , hspec >=2.6.0 && <2.8
+                  , hspec >=2.6.0 && <2.11
                   , QuickCheck
                   , lens
-                  , lens-aeson >=1.0.2    && <1.2
+                  , lens-aeson >=1.0.2    && <1.3
                   , servant
                   , servant-swagger
                   , swagger2

servant-swagger/src/Servant/Swagger.hs

@@ -55,6 +55,7 @@ import           Servant.Swagger.Internal.Orphans ()
 -- >>> import Data.Typeable
 -- >>> import GHC.Generics
 -- >>> import Servant.API
+-- >>> import System.Environment
 -- >>> import Test.Hspec
 -- >>> import Test.QuickCheck
 -- >>> import qualified Data.ByteString.Lazy.Char8 as BSL8
@@ -64,6 +65,7 @@ import           Servant.Swagger.Internal.Orphans ()
 -- >>> :set -XGeneralizedNewtypeDeriving
 -- >>> :set -XOverloadedStrings
 -- >>> :set -XTypeOperators
+-- >>> setEnv "HSPEC_COLOR" "no"
 -- >>> data User = User { name :: String, age :: Int } deriving (Show, Generic, Typeable)
 -- >>> newtype UserId = UserId Integer deriving (Show, Generic, Typeable, ToJSON)
 -- >>> instance ToJSON User
@@ -160,11 +162,11 @@ import           Servant.Swagger.Internal.Orphans ()
 -- >>> instance Arbitrary UserId where arbitrary = UserId <$> arbitrary
 -- >>> hspec $ validateEveryToJSON (Proxy :: Proxy UserAPI)
 -- <BLANKLINE>
--- [User]
+-- [User]...
 -- ...
--- User
+-- User...
 -- ...
--- UserId
+-- UserId...
 -- ...
 -- Finished in ... seconds
 -- 3 examples, 0 failures

servant-swagger/src/Servant/Swagger/Internal.hs

@@ -3,11 +3,13 @@
 {-# LANGUAGE DataKinds            #-}
 {-# LANGUAGE FlexibleContexts     #-}
 {-# LANGUAGE FlexibleInstances    #-}
+{-# LANGUAGE OverloadedLists      #-}
 {-# LANGUAGE OverloadedStrings    #-}
 {-# LANGUAGE PolyKinds            #-}
 {-# LANGUAGE RankNTypes           #-}
 {-# LANGUAGE ScopedTypeVariables  #-}
 {-# LANGUAGE TypeOperators        #-}
+{-# LANGUAGE TypeFamilies         #-}
 #if __GLASGOW_HASKELL__ >= 806
 {-# LANGUAGE UndecidableInstances #-}
 #endif
@@ -30,11 +32,13 @@ import qualified Data.Swagger                           as Swagger
 import           Data.Swagger.Declare
 import           Data.Text                              (Text)
 import qualified Data.Text                              as Text
+import           GHC.Generics                           (D1, Meta(..), Rep)
 import           GHC.TypeLits
 import           Network.HTTP.Media                     (MediaType)
 import           Servant.API
 import           Servant.API.Description                (FoldDescription,
                                                          reflectDescription)
+import           Servant.API.Generic                    (ToServantApi, AsApi)
 import           Servant.API.Modifiers                  (FoldRequired)
 
 import           Servant.Swagger.Internal.TypeLevel.API
@@ -149,6 +153,10 @@ mkEndpointNoContentVerb path _ = mempty
 addParam :: Param -> Swagger -> Swagger
 addParam param = allOperations.parameters %~ (Inline param :)
 
+-- | Add a tag to every operation in the spec.
+addTag :: Text -> Swagger -> Swagger
+addTag tag = allOperations.tags %~ ([tag] <>)
+
 -- | Add accepted content types to every operation in the spec.
 addConsumes :: [MediaType] -> Swagger -> Swagger
 addConsumes cs = allOperations.consumes %~ (<> Just (MimeList cs))
@@ -296,6 +304,10 @@ instance (HasSwagger sub) => HasSwagger (HttpVersion :> sub) where
 instance (HasSwagger sub) => HasSwagger (WithNamedContext x c sub) where
   toSwagger _ = toSwagger (Proxy :: Proxy sub)
 
+-- | @'WithResource'@ combinator does not change our specification at all.
+instance (HasSwagger sub) => HasSwagger (WithResource res :> sub) where
+  toSwagger _ = toSwagger (Proxy :: Proxy sub)
+
 instance (KnownSymbol sym, HasSwagger sub) => HasSwagger (sym :> sub) where
   toSwagger _ = prependPath piece (toSwagger (Proxy :: Proxy sub))
     where
@@ -439,6 +451,9 @@ instance (ToSchema a, Accept ct, HasSwagger sub, KnownSymbol (FoldDescription mo
         & required  ?~ True
         & schema    .~ ParamBody ref
 
+instance (HasSwagger (ToServantApi routes), KnownSymbol datatypeName, Rep (routes AsApi) ~ D1 ('MetaData datatypeName moduleName packageName isNewtype) f) => HasSwagger (NamedRoutes routes) where
+  toSwagger _ = addTag (Text.pack $ symbolVal (Proxy :: Proxy datatypeName)) (toSwagger (Proxy :: Proxy (ToServantApi routes)))
+
 -- =======================================================================
 -- Below are the definitions that should be in Servant.API.ContentTypes
 -- =======================================================================

servant-swagger/src/Servant/Swagger/Internal/Test.hs

@@ -29,10 +29,12 @@ import           Servant.Swagger.Internal.TypeLevel
 -- >>> import Control.Applicative
 -- >>> import GHC.Generics
 -- >>> import Test.QuickCheck
+-- >>> import System.Environment (setEnv)
 -- >>> :set -XDeriveGeneric
 -- >>> :set -XGeneralizedNewtypeDeriving
 -- >>> :set -XDataKinds
 -- >>> :set -XTypeOperators
+-- >>> setEnv "HSPEC_COLOR" "no"
 
 -- | Verify that every type used with @'JSON'@ content type in a servant API
 -- has compatible @'ToJSON'@ and @'ToSchema'@ instances using @'validateToJSON'@.
@@ -53,10 +55,10 @@ import           Servant.Swagger.Internal.TypeLevel
 --
 -- >>> hspec $ context "ToJSON matches ToSchema" $ validateEveryToJSON (Proxy :: Proxy UserAPI)
 -- <BLANKLINE>
--- ToJSON matches ToSchema
---   User
+-- ToJSON matches ToSchema...
+--   User...
 -- ...
---   UserId
+--   UserId...
 -- ...
 -- Finished in ... seconds
 -- 2 examples, 0 failures
@@ -118,11 +120,11 @@ validateEveryToJSONWithPatternChecker checker _ = props
 -- :}
 -- <BLANKLINE>
 -- read . show == id
---   Bool
+--   Bool...
 -- ...
---   Int
+--   Int...
 -- ...
---   [Char]
+--   [Char]...
 -- ...
 -- Finished in ... seconds
 -- 3 examples, 0 failures

servant/CHANGELOG.md

@@ -2,6 +2,11 @@
 
 Package versions follow the [Package Versioning Policy](https://pvp.haskell.org/): in A.B.C, bumps to either A or B represent major versions.
 
+0.19.1
+------
+
+Compatibility with GHC 9.4, see [PR #1592](https://github.com/haskell-servant/servant/pull/1592).
+
 0.19
 ----
 

servant/servant.cabal

@@ -1,6 +1,6 @@
 cabal-version:       2.2
 name:                servant
-version:             0.19
+version:             0.19.1
 
 synopsis:            A family of combinators for defining webservices APIs
 category:            Servant, Web
@@ -62,6 +62,7 @@ library
     Servant.API.Vault
     Servant.API.Verbs
     Servant.API.WithNamedContext
+    Servant.API.WithResource
 
   -- Types
   exposed-modules:
@@ -80,19 +81,19 @@ library
   --
   -- note: mtl lower bound is so low because of GHC-7.8
   build-depends:
-      base                   >= 4.9      && < 4.17
+      base                   >= 4.9      && < 4.18
     , bytestring             >= 0.10.8.1 && < 0.12
     , constraints            >= 0.2
-    , mtl                    >= 2.2.2    && < 2.3
+    , mtl                    ^>= 2.2.2   || ^>= 2.3.1
     , sop-core               >= 0.4.0.0  && < 0.6
-    , transformers           >= 0.5.2.0  && < 0.6
+    , transformers           >= 0.5.2.0  && < 0.7
     , text                   >= 1.2.3.0  && < 2.1
 
 
   -- We depend (heavily) on the API of these packages:
   -- i.e. re-export, or allow using without direct dependency
   build-depends:
-      http-api-data          >= 0.4.1    && < 0.4.4
+      http-api-data          >= 0.4.1    && < 0.5.1
     , singleton-bool         >= 0.1.4    && < 0.1.7
 
   -- Other dependencies: Lower bound around what is in the latest Stackage LTS.
@@ -166,9 +167,9 @@ test-suite spec
 
   -- Additional dependencies
   build-depends:
-      hspec                >= 2.6.0    && < 2.9
+      hspec                >= 2.6.0    && < 2.10
     , QuickCheck           >= 2.12.6.1 && < 2.15
     , quickcheck-instances >= 0.3.19   && < 0.4
 
   build-tool-depends:
-    hspec-discover:hspec-discover >= 2.6.0 && < 2.9
+    hspec-discover:hspec-discover >= 2.6.0 && < 2.10

servant/src/Servant/API.hs

@@ -31,6 +31,8 @@ module Servant.API (
   -- | Access the location for arbitrary data to be shared by applications and middleware
   module Servant.API.WithNamedContext,
   -- | Access context entries in combinators in servant-server
+  module Servant.API.WithResource,
+  -- | Access a managed resource scoped to a single request
 
   -- * Actual endpoints, distinguished by HTTP method
   module Servant.API.Verbs,
@@ -101,17 +103,19 @@ import           Servant.API.Experimental.Auth
                  (AuthProtect)
 import           Servant.API.Fragment
                  (Fragment)
+import           Servant.API.Generic
+                 (AsApi, GServantProduct, GenericMode ((:-)), GenericServant,
+                 ToServant, ToServantApi, fromServant, genericApi, toServant)
 import           Servant.API.Header
                  (Header, Header')
-import           Servant.API.Generic
-                 (GenericMode ((:-)), AsApi, ToServant, ToServantApi, GServantProduct,
-                 GenericServant, fromServant, toServant, genericApi)
 import           Servant.API.HttpVersion
                  (HttpVersion (..))
 import           Servant.API.IsSecure
                  (IsSecure (..))
 import           Servant.API.Modifiers
                  (Lenient, Optional, Required, Strict)
+import           Servant.API.NamedRoutes
+                 (NamedRoutes)
 import           Servant.API.QueryParam
                  (QueryFlag, QueryParam, QueryParam', QueryParams)
 import           Servant.API.Raw
@@ -137,8 +141,6 @@ import           Servant.API.UVerb
                  Unique, WithStatus (..), inject, statusOf)
 import           Servant.API.Vault
                  (Vault)
-import           Servant.API.NamedRoutes
-                 (NamedRoutes)
 import           Servant.API.Verbs
                  (Delete, DeleteAccepted, DeleteNoContent,
                  DeleteNonAuthoritative, Get, GetAccepted, GetNoContent,
@@ -150,6 +152,8 @@ import           Servant.API.Verbs
                  ReflectMethod (reflectMethod), StdMethod (..), Verb)
 import           Servant.API.WithNamedContext
                  (WithNamedContext)
+import           Servant.API.WithResource
+                 (WithResource)
 import           Servant.Links
                  (HasLink (..), IsElem, IsElem', Link, URI (..), safeLink)
 import           Web.HttpApiData

servant/src/Servant/API/ContentTypes.hs

@@ -295,7 +295,7 @@ instance {-# OVERLAPPABLE #-}
 -- then this would be taken care of. However there is no more specific instance
 -- between that and 'MimeRender JSON a', so we do this instead
 instance {-# OVERLAPPING #-} ( Accept ctyp ) => AllMimeRender '[ctyp] NoContent where
-    allMimeRender _ _ = map (, "") $ NE.toList $ contentTypes pctyp
+    allMimeRender _ NoContent = map (, "") $ NE.toList $ contentTypes pctyp
       where
         pctyp = Proxy :: Proxy ctyp
 

servant/src/Servant/API/TypeLevel.hs

@@ -110,7 +110,7 @@ type family IsElem' a s :: Constraint
 --
 -- >>> ok (Proxy :: Proxy (IsElem ("bye" :> Get '[JSON] Int) SampleAPI))
 -- ...
--- ... Could not deduce...
+-- ... Could not ...
 -- ...
 --
 -- An endpoint is considered within an api even if it is missing combinators
@@ -151,7 +151,7 @@ type family IsElem endpoint api :: Constraint where
 --
 -- >>> ok (Proxy :: Proxy (IsSubAPI (SampleAPI :<|> Get '[JSON] Int) SampleAPI))
 -- ...
--- ... Could not deduce...
+-- ... Could not ...
 -- ...
 --
 -- This uses @IsElem@ for checking; thus the note there applies here.
@@ -174,7 +174,7 @@ type family AllIsElem xs api :: Constraint where
 --
 -- >>> ok (Proxy :: Proxy (IsIn (Get '[JSON] Int) (Header "h" Bool :> Get '[JSON] Int)))
 -- ...
--- ... Could not deduce...
+-- ... Could not ...
 -- ...
 type family IsIn (endpoint :: *) (api :: *) :: Constraint where
   IsIn e (sa :<|> sb)                = Or (IsIn e sa) (IsIn e sb)

servant/src/Servant/API/UVerb.hs

@@ -38,6 +38,7 @@ import GHC.TypeLits (Nat)
 import Network.HTTP.Types (Status, StdMethod)
 import Servant.API.ContentTypes (JSON, PlainText, FormUrlEncoded, OctetStream, NoContent, MimeRender(mimeRender), MimeUnrender(mimeUnrender))
 import Servant.API.Status (KnownStatus, statusVal)
+import Servant.API.ResponseHeaders (Headers)
 import Servant.API.UVerb.Union
 
 class KnownStatus (StatusOf a) => HasStatus (a :: *) where
@@ -52,6 +53,9 @@ statusOf = const (statusVal (Proxy :: Proxy (StatusOf a)))
 instance HasStatus NoContent where
   type StatusOf NoContent = 204
 
+instance HasStatus a => HasStatus (Headers hs a) where
+  type StatusOf (Headers hs a) = StatusOf a
+
 class HasStatuses (as :: [*]) where
   type Statuses (as :: [*]) :: [Nat]
   statuses :: Proxy as -> [Status]

servant/src/Servant/API/UVerb/Union.hs

@@ -128,9 +128,9 @@ type DuplicateElementError (rs :: [k]) =
     ':$$: 'Text "    " ':<>: 'ShowType rs
 
 type family Elem (x :: k) (xs :: [k]) :: Bool where
+  Elem x (x ': _) = 'True
+  Elem x (_ ': xs) = Elem x xs
   Elem _ '[] = 'False
-  Elem x (x' ': xs) =
-    If (x == x') 'True (Elem x xs)
 
 type family Unique xs :: Constraint where
   Unique xs = If (Nubbed xs == 'True) (() :: Constraint) (TypeError (DuplicateElementError xs))

servant/src/Servant/API/WithResource.hs

@@ -0,0 +1,3 @@
+module Servant.API.WithResource (WithResource) where
+
+data WithResource res

servant/src/Servant/Links.hs

@@ -1,5 +1,6 @@
 {-# LANGUAGE AllowAmbiguousTypes    #-}
 {-# LANGUAGE ConstraintKinds        #-}
+{-# LANGUAGE CPP                    #-}
 {-# LANGUAGE DataKinds              #-}
 {-# LANGUAGE FlexibleContexts       #-}
 {-# LANGUAGE FlexibleInstances      #-}
@@ -91,7 +92,7 @@
 -- >>> let bad_link = Proxy :: Proxy ("hello" :> Delete '[JSON] NoContent)
 -- >>> safeLink api bad_link
 -- ...
--- ...Could not deduce...
+-- ...Could not ...
 -- ...
 --
 --  This error is essentially saying that the type family couldn't find
@@ -192,7 +193,11 @@ import           Servant.API.Verbs
                  (Verb, NoContentVerb)
 import           Servant.API.WithNamedContext
                  (WithNamedContext)
+import           Servant.API.WithResource
+                 (WithResource)
 import           Web.HttpApiData
+import           Data.Kind
+                 (Type)
 
 -- | A safe link datatype.
 -- The only way of constructing a 'Link' is using 'safeLink', which means any
@@ -555,6 +560,10 @@ instance HasLink sub => HasLink (WithNamedContext name context sub) where
     type MkLink (WithNamedContext name context sub) a = MkLink sub a
     toLink toA _ = toLink toA (Proxy :: Proxy sub)
 
+instance HasLink sub => HasLink (WithResource res :> sub) where
+    type MkLink (WithResource res :> sub) a = MkLink sub a
+    toLink toA _ = toLink toA (Proxy :: Proxy sub)
+
 instance HasLink sub => HasLink (RemoteHost :> sub) where
     type MkLink (RemoteHost :> sub) a = MkLink sub a
     toLink = simpleToLink (Proxy :: Proxy sub)
@@ -647,12 +656,20 @@ simpleToLink _ toA _ = toLink toA (Proxy :: Proxy sub)
 -- >>> import Data.Text (Text)
 
 -- Erroring instance for 'HasLink' when a combinator is not fully applied
-instance TypeError (PartialApplication HasLink arr) => HasLink ((arr :: a -> b) :> sub)
+instance TypeError (PartialApplication 
+#if __GLASGOW_HASKELL__ >= 904
+                    @(Type -> Constraint) 
+#endif
+                    HasLink arr) => HasLink ((arr :: a -> b) :> sub)
   where
     type MkLink (arr :> sub) _ = TypeError (PartialApplication (HasLink :: * -> Constraint) arr)
     toLink = error "unreachable"
 
 -- Erroring instances for 'HasLink' for unknown API combinators
-instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub HasLink ty) => HasLink (ty :> sub)
+instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub 
+#if __GLASGOW_HASKELL__ >= 904
+                                         @(Type -> Constraint) 
+#endif
+                                         HasLink ty) => HasLink (ty :> sub)
 
 instance {-# OVERLAPPABLE #-} TypeError (NoInstanceFor (HasLink api)) => HasLink api

servant/src/Servant/Test/ComprehensiveAPI.hs

@@ -72,6 +72,7 @@ type ComprehensiveAPIWithoutStreamingOrRaw' endpoint =
     :<|> "description"      :> Description "foo" :> GET
     :<|> "alternative"      :> ("left" :> GET :<|> "right" :> GET)
     :<|> "fragment"         :> Fragment Int :> GET
+    :<|> "resource"         :> WithResource Int :> GET
     :<|> endpoint
 
 type ComprehensiveAPIWithoutStreamingOrRaw = ComprehensiveAPIWithoutStreamingOrRaw' EmptyEndpoint

servant/src/Servant/Types/SourceT.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP                 #-}
 {-# LANGUAGE DeriveFunctor       #-}
 {-# LANGUAGE GADTs               #-}
 {-# LANGUAGE RankNTypes          #-}
@@ -154,8 +155,10 @@ instance (Applicative m, Show1 m, Show a) => Show (StepT m a) where
 -- | >>> lift [1,2,3] :: StepT [] Int
 -- Effect [Yield 1 Stop,Yield 2 Stop,Yield 3 Stop]
 --
+#if !MIN_VERSION_transformers(0,6,0)
 instance MonadTrans StepT where
     lift = Effect . fmap (`Yield` Stop)
+#endif
 
 instance MFunctor StepT where
     hoist f = go where

servant/test/Servant/API/ContentTypesSpec.hs

@@ -33,6 +33,8 @@ import           Data.String.Conversions
 import qualified Data.Text                                        as TextS
 import qualified Data.Text.Encoding                               as TextSE
 import qualified Data.Text.Lazy                                   as TextL
+import           Control.Exception
+                 (evaluate)
 import           GHC.Generics
 import           Test.Hspec
 import           Test.QuickCheck
@@ -78,6 +80,15 @@ spec = describe "Servant.API.ContentTypes" $ do
         it "has mimeUnrender reverse mimeRender for valid top-level json " $ do
             property $ \x -> mimeUnrender p (mimeRender p x) == Right (x::SomeData)
 
+    describe "The NoContent Content-Type type" $ do
+        let p = Proxy :: Proxy '[JSON]
+
+        it "does not render any content" $
+          allMimeRender p NoContent `shouldSatisfy` (all (BSL8.null . snd))
+
+        it "evaluates the NoContent value" $
+          evaluate (allMimeRender p (undefined :: NoContent)) `shouldThrow` anyErrorCall
+
     describe "The PlainText Content-Type type" $ do
         let p = Proxy :: Proxy PlainText
 

servant/test/Servant/API/ResponseHeadersSpec.hs

@@ -2,10 +2,14 @@
 {-# LANGUAGE OverloadedStrings #-}
 module Servant.API.ResponseHeadersSpec where
 
+import           Data.Proxy
+import           GHC.TypeLits
 import           Test.Hspec
 
+import           Servant.API.ContentTypes
 import           Servant.API.Header
 import           Servant.API.ResponseHeaders
+import           Servant.API.UVerb
 
 spec :: Spec
 spec = describe "Servant.API.ResponseHeaders" $ do
@@ -28,3 +32,10 @@ spec = describe "Servant.API.ResponseHeaders" $ do
     it "does not add a header" $ do
       let val = noHeader 5 :: Headers '[Header "test" Int] Int
       getHeaders val `shouldBe` []
+
+  describe "HasStatus Headers" $ do
+
+    it "gets the status from the underlying value" $ do
+      natVal (Proxy :: Proxy (StatusOf (Headers '[Header "first" Int] NoContent))) `shouldBe` 204
+      natVal (Proxy :: Proxy (StatusOf (Headers '[Header "first" Int] (WithStatus 503 ())))) `shouldBe` 503
+