From edaef11a43e1ec05c1143a182412a272133de86e Mon Sep 17 00:00:00 2001
From: Simon Hengel <sol@typeful.net>
Date: Fri, 12 Jul 2024 01:54:04 +0700
Subject: [PATCH] Add `cabal-doctest`

---
 .gitattributes          |  3 +--
 doctest.cabal           | 30 ++++++++++++++++++++++++++++++
 driver/cabal-doctest.hs | 36 ++++++++++++++++++++++++++++++++++++
 package.yaml            | 18 +++++++++++++-----
 4 files changed, 80 insertions(+), 7 deletions(-)
 create mode 100644 driver/cabal-doctest.hs

diff --git a/.gitattributes b/.gitattributes
index 1f70750d..e0c9dafa 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,2 +1 @@
-/doctest.cabal linguist-generated=true
-/ghci-wrapper/ghci-wrapper.cabal linguist-generated=true
+doctest.cabal linguist-generated=true
diff --git a/doctest.cabal b/doctest.cabal
index eafb6e02..4537c6e6 100644
--- a/doctest.cabal
+++ b/doctest.cabal
@@ -155,6 +155,36 @@ library
   if impl(ghc >= 9.8)
     ghc-options: -fno-warn-x-partial
 
+executable cabal-doctest
+  main-is: cabal-doctest.hs
+  other-modules:
+      Main
+      Paths_doctest
+  hs-source-dirs:
+      driver
+  default-extensions:
+      NamedFieldPuns
+      RecordWildCards
+      DeriveFunctor
+      NoImplicitPrelude
+  ghc-options: -Wall -threaded
+  build-depends:
+      base >=4.5 && <5
+    , code-page >=0.1
+    , deepseq
+    , directory
+    , exceptions
+    , filepath
+    , ghc >=8.0 && <9.11
+    , ghc-paths >=0.1.0.9
+    , process
+    , syb >=0.3
+    , temporary
+    , transformers
+  default-language: Haskell2010
+  if impl(ghc >= 9.8)
+    ghc-options: -fno-warn-x-partial
+
 executable doctest
   main-is: Main.hs
   other-modules:
diff --git a/driver/cabal-doctest.hs b/driver/cabal-doctest.hs
new file mode 100644
index 00000000..5ab343ad
--- /dev/null
+++ b/driver/cabal-doctest.hs
@@ -0,0 +1,36 @@
+{-# LANGUAGE LambdaCase #-}
+module Main (main) where
+
+import           Prelude
+
+import           Data.Version
+import           System.Environment
+import           System.Exit
+import           System.FilePath
+import           System.IO.Temp (withSystemTempDirectory)
+import           System.Process
+
+import           Paths_doctest (version)
+
+main :: IO ()
+main = do
+  args <- getArgs
+  lookupEnv "CABAL" >>= \ case
+    Nothing -> run "cabal" args
+    Just cabal -> run cabal (drop 1 args)
+
+run :: String -> [String] -> IO ()
+run cabal args = withSystemTempDirectory "doctest" $ \ dir -> do
+  let
+    doctest = dir </> "doctest"
+    script = dir </> "init-ghci"
+  callProcess cabal ["install", "--ignore-project", "--installdir=" <> dir, "--install-method=symlink", "doctest-" <> showVersion version]
+  callProcess (dir </> "doctest") ["--version"]
+  callProcess cabal ("build" : "--only-dependencies" : args)
+  writeFile script ":seti -w -Wdefault"
+  spawnProcess cabal ("repl"
+    : "--build-depends=QuickCheck"
+    : "--build-depends=template-haskell"
+    : "--repl-options=-ghci-script=" <> script
+    : "--with-ghc" : doctest
+    : args) >>= waitForProcess >>= exitWith
diff --git a/package.yaml b/package.yaml
index 60b2e363..39d67d89 100644
--- a/package.yaml
+++ b/package.yaml
@@ -59,11 +59,19 @@ library:
   - Test.DocTest.Internal.Parse
   - Test.DocTest.Internal.Run
 
-executable:
-  main: Main.hs
-  ghc-options: -threaded
-  source-dirs: driver
-  dependencies: doctest
+executables:
+  doctest:
+    main: Main.hs
+    ghc-options: -threaded
+    source-dirs: driver
+    dependencies: doctest
+
+  cabal-doctest:
+    main: cabal-doctest.hs
+    ghc-options: -threaded
+    source-dirs: driver
+    dependencies:
+    - temporary
 
 tests:
   spec: