Switch to cabal-doctest

Closes #29

Setup.hs

@@ -1,2 +1,6 @@
-import Distribution.Simple
-main = defaultMain
+module Main where
+
+import Distribution.Extra.Doctest (defaultMainWithDoctests)
+
+main :: IO ()
+main = defaultMainWithDoctests "doctests"

exact-real.cabal

@@ -1,10 +1,10 @@
-cabal-version: 1.12
+cabal-version: 1.24
 
 -- This file has been generated from package.yaml by hpack version 0.33.0.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 6f3e15d9117341483cf66f37de3053937a4e86fc60db22da88c152c7c3b4a5c5
+-- hash: 94cf687afccded481cfdea2fa373bddbcfc589c1e6acf61feeb0998b943a9ce9
 
 name:           exact-real
 version:        0.12.2
@@ -19,7 +19,7 @@ copyright:      2015 Joe Hermaszewski
 license:        MIT
 license-file:   LICENSE
 tested-with:    GHC>=8.2.2 && <=8.6.5
-build-type:     Simple
+build-type:     Custom
 extra-source-files:
     .gitignore
     readme.md
@@ -31,6 +31,12 @@ source-repository head
   type: git
   location: https://github.com/expipiplus1/exact-real
 
+custom-setup
+  setup-depends:
+      Cabal
+    , base
+    , cabal-doctest >=1 && <1.1
+
 library
   exposed-modules:
       Data.CReal
@@ -48,19 +54,16 @@ library
     , random >=1.0
   default-language: Haskell2010
 
-test-suite doctest
+test-suite doctests
   type: exitcode-stdio-1.0
-  main-is: DocTest.hs
+  main-is: Doctests.hs
+  other-modules:
+
   hs-source-dirs:
       test
-  ghc-options: -Wall -threaded
   build-depends:
-      base >=4
-    , directory >=1.0
-    , doctest >=0.8
-    , filepath >=1.3
-  if impl(ghc < 8.0.0)
-    buildable: False
+      base
+    , doctest
   default-language: Haskell2010
 
 test-suite test

package.yaml

@@ -71,21 +71,14 @@ tests:
         condition: impl(ghc < 8.0.0)
         buildable: false
 
-  doctest:
-    main: DocTest.hs
-    other-modules: []
-    source-dirs: test
-    ghc-options:
-    - -Wall
-    - -threaded
+  doctests:
+    main: Doctests.hs
+    other-modules: ""
+    source-dirs:
+      - test
     dependencies:
-    - base >=4
-    - directory >=1.0
-    - doctest >=0.8
-    - filepath >=1.3
-    when:
-        condition: impl(ghc < 8.0.0)
-        buildable: false
+      - base
+      - doctest
 
 benchmarks:
   bench:
@@ -99,3 +92,9 @@ benchmarks:
     - base >=4
     - criterion >=1.1
     - exact-real
+
+custom-setup:
+ dependencies:
+   - base
+   - Cabal
+   - cabal-doctest >= 1 && <1.1

test/Doctests.hs

@@ -0,0 +1,10 @@
+module Main where
+
+import           Build_doctests                 ( flags
+                                                , module_sources
+                                                , pkgs
+                                                )
+import           Test.DocTest                   ( doctest )
+
+main :: IO ()
+main = doctest $ flags <> pkgs <> module_sources