Update to work with LTS-12.x and Servant 0.14

.travis.yml

@@ -1,6 +1,6 @@
 # This Travis job script has been generated by a script via
 #
-#   haskell-ci '--output=.travis.yml' '--branches=master' 'cabal.project'
+#   haskell-ci '--output=.travis.yml' '--config=cabal.haskell-ci' 'cabal.project'
 #
 # For more information, see https://github.com/haskell-CI/haskell-ci
 #
@@ -115,5 +115,15 @@ script:
   # Build without installed constraints for packages in global-db
   - rm -f cabal.project.local; ${CABAL} new-build -w ${HC} --disable-tests --disable-benchmarks all;
 
-# REGENDATA ["--output=.travis.yml","--branches=master","cabal.project"]
+  # Constraint sets
+  - rm -rf cabal.project.local
+
+  # Constraint set servant-0.15
+  - ${CABAL} new-build -w ${HC} --disable-tests --disable-benchmarks  --constraint='servant ==0.15.*' all
+
+  # Constraint set servant-0.16
+  - ${CABAL} new-build -w ${HC} --disable-tests --disable-benchmarks  --constraint='servant ==0.16.*' all
+
+
+# REGENDATA ["--output=.travis.yml","--config=cabal.haskell-ci","cabal.project"]
 # EOF

README.md

@@ -0,0 +1,41 @@
+# servant-ekg
+
+[![Build Status](https://travis-ci.org/haskell-servant/servant-ekg.png)](https://travis-ci.org/haskell-servant/servant-ekg)
+
+# Servant Performance Counters
+
+This package lets you track peformance counters for each of your Servant endpoints using EKG.
+
+# Usage
+
+Servant-EKG knows how to handle all official Servant combinators out of the box.
+
+## Instrumenting your API
+To use Servant-EKG, you'll need to wrap your WAI application with the Servant-EKG middleware.
+
+```
+import Network.Wai.Handler.Warp
+import System.Metrics
+import Servant.Ekg
+
+wrapWithEkg :: Proxy api -> Server api -> IO Application
+wrapWithEkg api server = do
+  store   <- newStore
+  metrics <- newMVar mempty
+
+  return $ monitorEndpoints api store metrics (serve api server)
+
+main :: IO ()
+main = do
+  let api    = ...
+      server = ...
+
+  app <- wrapWithEkg api server
+
+  run 8080 app
+```
+
+## Runtime overhead
+Instrumenting your API introduces a non-zero runtime overhead, on the order of 200 - 600 µsec depending upon your machine. It's a good idea to run the benchmarks on your intended production platform to get an idea of how large the overhead will be. You'll need to have `wrk` installed to run the benchmarks.
+
+In general, the runtime overhead should be effectively negligible if your handlers are issuing network requests, such as to databases. If you have handlers that are small, CPU-only, and requested frequently, you will see a performance hit from Servant-EKG.

cabal.haskell-ci

@@ -0,0 +1,9 @@
+branches: master
+
+constraint-set servant-0.15
+  ghc: >= 8.0 && <8.8
+  constraints: servant ==0.15.*
+
+constraint-set servant-0.16
+  ghc: >= 8.0 && <8.8
+  constraints: servant ==0.16.*

lib/Servant/Ekg.hs

@@ -4,10 +4,10 @@
 {-# LANGUAGE FlexibleInstances   #-}
 {-# LANGUAGE KindSignatures      #-}
 {-# LANGUAGE OverloadedStrings   #-}
+{-# LANGUAGE PolyKinds           #-}
 {-# LANGUAGE RecordWildCards     #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeOperators       #-}
-{-# LANGUAGE PolyKinds           #-}
 module Servant.Ekg where
 
 import           Control.Concurrent.MVar
@@ -116,6 +116,7 @@ instance (KnownSymbol (path :: Symbol), HasEndpoint (sub :: *))
                 return (p:end, method)
             _ -> Nothing
 
+
 instance (KnownSymbol (capture :: Symbol), HasEndpoint (sub :: *))
     => HasEndpoint (Capture' mods capture a :> sub) where
     getEndpoint _ req =
@@ -147,8 +148,10 @@ instance HasEndpoint (sub :: *) => HasEndpoint (QueryFlag h :> sub) where
 instance HasEndpoint (sub :: *) => HasEndpoint (ReqBody' mods cts a :> sub) where
     getEndpoint _ = getEndpoint (Proxy :: Proxy sub)
 
+#if MIN_VERSION_servant(0,15,0)
 instance HasEndpoint (sub :: *) => HasEndpoint (StreamBody' mods framing ct a :> sub) where
     getEndpoint _ = getEndpoint (Proxy :: Proxy sub)
+#endif
 
 instance HasEndpoint (sub :: *) => HasEndpoint (RemoteHost :> sub) where
     getEndpoint _ = getEndpoint (Proxy :: Proxy sub)
@@ -168,19 +171,17 @@ instance HasEndpoint (sub :: *) => HasEndpoint (WithNamedContext x y sub) where
 instance ReflectMethod method => HasEndpoint (Verb method status cts a) where
     getEndpoint _ req = case pathInfo req of
         [] | requestMethod req == method -> Just ([], method)
-        _ -> Nothing
+        _                                -> Nothing
       where method = reflectMethod (Proxy :: Proxy method)
 
 instance ReflectMethod method => HasEndpoint (Stream method status framing ct a) where
     getEndpoint _ req = case pathInfo req of
         [] | requestMethod req == method -> Just ([], method)
-        _ -> Nothing
+        _                                -> Nothing
       where method = reflectMethod (Proxy :: Proxy method)
 
-instance HasEndpoint (Raw) where
+instance HasEndpoint Raw where
     getEndpoint _ _ = Just ([],"RAW")
 
-#if MIN_VERSION_servant(0,8,1)
 instance HasEndpoint (sub :: *) => HasEndpoint (CaptureAll (h :: Symbol) a :> sub) where
     getEndpoint _ = getEndpoint (Proxy :: Proxy sub)
-#endif

servant-ekg.cabal

@@ -1,6 +1,6 @@
 cabal-version: >=1.10
 name:          servant-ekg
-version:       0.2.1.0
+version:       0.2.2.0
 synopsis:      Helpers for using ekg with servant
 description:   Helpers for using ekg with servant, e.g.. counters per endpoint.
 license:       BSD3
@@ -24,13 +24,13 @@ library
   hs-source-dirs:   lib
   build-depends:
       base                  >=4.9      && <4.13
-    , ekg-core              >=0.1.1.6  && <0.2
+    , ekg-core              >=0.1.1.4  && <0.2
     , http-types            >=0.12.2   && <0.13
-    , servant               >=0.15     && <0.17
+    , servant               >=0.14     && <0.17
     , text                  >=1.2.3.0  && <1.3
     , time                  >=1.6.0.1  && <1.9
     , unordered-containers  >=0.2.9.0  && <0.3
-    , wai                   >=3.2.2    && <3.3
+    , wai                   >=3.2.0    && <3.3
 
   default-language: Haskell2010
 

test/Servant/EkgSpec.hs

@@ -1,28 +1,34 @@
-{-# LANGUAGE CPP                  #-}
+{-# LANGUAGE CPP               #-}
-{-# LANGUAGE DataKinds            #-}
+{-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE DeriveGeneric        #-}
+{-# LANGUAGE DeriveGeneric     #-}
-{-# LANGUAGE OverloadedStrings    #-}
+{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE PolyKinds            #-}
+{-# LANGUAGE PolyKinds         #-}
-{-# LANGUAGE TypeFamilies         #-}
+{-# LANGUAGE RankNTypes        #-}
-{-# LANGUAGE TypeOperators        #-}
+{-# LANGUAGE TypeFamilies      #-}
+{-# LANGUAGE TypeOperators     #-}
 
 module Servant.EkgSpec (spec) where
 
 import           Control.Concurrent
 import           Data.Aeson
-import           Data.Monoid
+import qualified Data.HashMap.Strict                        as H
+import           Data.Monoid                                ((<>))
 import           Data.Proxy
-import qualified Data.HashMap.Strict as H
 import           Data.Text
 import           GHC.Generics
-import           Network.HTTP.Client (defaultManagerSettings, newManager)
+import           Network.HTTP.Client                        (defaultManagerSettings,
+                                                             newManager)
 import           Network.Wai
 import           Network.Wai.Handler.Warp
 import           Servant
 import           Servant.Client
-import           Servant.Test.ComprehensiveAPI (comprehensiveAPI)
+#if MIN_VERSION_servant(0,15,0)
+import           Servant.Test.ComprehensiveAPI              (comprehensiveAPI)
+#else
+import           Servant.API.Internal.Test.ComprehensiveAPI (comprehensiveAPI)
+#endif
 import           System.Metrics
-import qualified System.Metrics.Counter as Counter
+import qualified System.Metrics.Counter                     as Counter
 import           Test.Hspec
 
 import           Servant.Ekg
@@ -38,7 +44,7 @@ spec = describe "servant-ekg" $ do
 
   let getEp :<|> postEp :<|> deleteEp = client testApi
 
-  it "collects number of request" $ do
+  it "collects number of request" $
     withApp $ \port mvar -> do
       mgr <- newManager defaultManagerSettings
       let runFn :: ClientM a -> IO (Either ClientError a)
@@ -101,11 +107,7 @@ server = helloH :<|> postGreetH :<|> deleteGreetH
 
         postGreetH = return
 
-#if MIN_VERSION_servant(0,8,0)
         deleteGreetH _ = return NoContent
-#else
-        deleteGreetH _ = return ()
-#endif
 
 -- Turn the server into a WAI app. 'serve' is provided by servant,
 -- more precisely by the Servant.Server module.