Make Txt2Tags test pass.

We don't have a good way to set things that aren't in the common
state. That will be the next order of business.

pandoc.cabal

@@ -518,7 +518,8 @@ Test-Suite test-pandoc
                   containers >= 0.1 && < 0.6,
                   ansi-terminal >= 0.5 && < 0.7,
                   executable-path >= 0.0 && < 0.1,
-                  zip-archive >= 0.2.3.4 && < 0.4
+                  zip-archive >= 0.2.3.4 && < 0.4,
+                  mtl >= 2.2 && < 2.3
   Other-Modules:  Tests.Old
                   Tests.Helpers
                   Tests.Shared

src/Text/Pandoc/Class.hs

@@ -32,6 +32,7 @@ Typeclass for pandoc readers and writers, allowing both IO and pure instances.
 -}
 
 module Text.Pandoc.Class ( PandocMonad(..)
+                         , CommonState(..)
                          , PureState(..)
                          , PureEnv(..)
                          , getPOSIXTime

tests/Tests/Readers/Txt2Tags.hs

@@ -4,16 +4,21 @@ module Tests.Readers.Txt2Tags (tests) where
 import Text.Pandoc.Definition
 import Test.Framework
 import Tests.Helpers
+import Control.Monad.State
 import Text.Pandoc.Arbitrary()
 import Text.Pandoc.Builder
 import Text.Pandoc
 import Data.List (intersperse)
-import Text.Pandoc.Readers.Txt2Tags
+import Text.Pandoc.Class
 
 
 t2t :: String -> Pandoc
 -- t2t = handleError . readTxt2Tags (T2TMeta "date" "mtime" "in" "out") def
-t2t = purely $ readTxt2Tags def
+t2t = purely $ \s -> do
+  put def { stInputFiles = Just ["in"]
+          , stOutputFile = Just "out"
+          }
+  readTxt2Tags def s
 
 infix 4 =:
 (=:) :: ToString c
@@ -80,10 +85,10 @@ tests =
 
       , "Macros: Date" =:
           "%%date" =?>
-            para "date"
+            para "1970-01-01"
       , "Macros: Mod Time" =:
           "%%mtime" =?>
-            para "mtime"
+            para ""
       , "Macros: Infile" =:
           "%%infile" =?>
             para "in"