Remove automatic hpack conversion (#148)

CHANGELOG.md

@@ -6,6 +6,7 @@
     - #138: Add `checks` to `outputs` submodule
     - #143: Changed `autoWire` to be an enum type, for granular controlling of which outputs to autowire.
 - #137: Expose cabal executables as flake apps. Add a corresponding `outputs.apps` option, while the `outputs.localPackages` option is renamed to `outputs.packages` (it now contains package metadata, including packages and its executables).
+- #148: Remove automatic hpack->cabal generation. Use `pre-commit-hooks.nix` instead.
 
 ## 0.2.0 (Mar 13, 2023)
 

doc/start.md

@@ -36,7 +36,6 @@ When nixifying a Haskell project without flake-parts (thus without haskell-flake
 In addition, compared to using plain nixpkgs, haskell-flake supports:
 
 - Auto-detection of local packages based on `cabal.project` file (via [haskell-parsers](https://github.com/srid/haskell-flake/tree/master/nix/haskell-parsers))
-- Support for hpack's `package.yaml`
 - Parse executables from `.cabal` file 
 - Composition of dependency overrides, and other project settings, via [[modules]]
 

nix/build-haskell-package.nix

@@ -8,27 +8,6 @@ let
 
   fromSdist = self.buildFromCabalSdist or (builtins.trace "Your version of Nixpkgs does not support hs.buildFromCabalSdist yet." (pkg: pkg));
 
-  # If `root` has package.yaml, but no cabal file, generate the cabal
-  # file and return the new source tree.
-  realiseHpack = name: root:
-    let
-      contents = lib.attrNames (builtins.readDir root);
-      hasCabal = lib.any (lib.strings.hasSuffix ".cabal") contents;
-      hasHpack = builtins.elem "package.yaml" contents;
-    in
-    if (!hasCabal && hasHpack)
-    then
-      pkgs.runCommand
-        "${name}-hpack"
-        { nativeBuildInputs = [ pkgs.hpack ]; }
-        ''
-          cp -r ${root} $out
-          chmod u+w $out
-          cd $out
-          hpack
-        ''
-    else root;
-
   makeSrcAutonomous = name: root: pkg: hlib.overrideSrc
     {
       src =
@@ -47,16 +26,12 @@ in
 
 name: pkgCfg:
 let
-  # NOTE: Even though cabal2nix does run hpack automatically,
-  # buildFromCabalSdist does not. So we must run hpack ourselves at
-  # the original source level.
-  root = realiseHpack name pkgCfg.root;
-  pkg = self.callCabal2nix name root { };
+  pkg = self.callCabal2nix name pkgCfg.root { };
 in
 lib.pipe pkg
   [
     # Avoid rebuilding because of changes in parent directories
-    (makeSrcAutonomous name root)
+    (makeSrcAutonomous name pkgCfg.root)
 
     # Make sure all files we use are included in the sdist, as a check
     # for release-worthiness.

nix/haskell-parsers/README.md

@@ -1,10 +1,9 @@
 # `haskell-parsers`
 
-`haskell-parsers` provides parsers for Haskell associated files: hpack, cabal and cabal.project. It provides:
+`haskell-parsers` provides parsers for Haskell associated files: cabal and cabal.project. It provides:
 
 - **`findPackagesInCabalProject`**: a superior alternative to nixpkgs' [`haskellPathsInDir`](https://github.com/NixOS/nixpkgs/blob/f991762ea1345d850c06cd9947700f3b08a12616/lib/filesystem.nix#L18).
   - It locates packages based on the "packages" field of `cabal.project` file if it exists (otherwise it returns the top-level package).
-  - It supports `hpack`, thus works with `package.yaml` even if no `.cabal` file exists.
 - **`getCabalExecutables`**: a function to extract executables from a `.cabal` file.
 
 ## Limitations

nix/haskell-parsers/default.nix

@@ -17,31 +17,17 @@ let
       else if num == 1
       then builtins.head cabalFiles
       else throwError "Expected a single .cabal file, but found multiple: ${builtins.toJSON cabalFiles}";
-    findSinglePackageYamlFile = path:
-      let f = path + "/package.yaml";
-      in if builtins.pathExists f then f else null;
     getCabalName =
       lib.strings.removeSuffix ".cabal";
-    getPackageYamlName = fp:
-      let
-        name = parser.parsePackageYamlName (builtins.readFile fp);
-      in
-      if name.type == "success"
-      then name.value
-      else throwError "Failed to parse ${fp}: ${builtins.toJSON name}";
     findHaskellPackageNameOfDirectory = path:
       let
         cabalFile = findSingleCabalFile path;
-        packageYamlFile = findSinglePackageYamlFile path;
       in
       if cabalFile != null
       then
         getCabalName cabalFile
-      else if packageYamlFile != null
-      then
-        getPackageYamlName packageYamlFile
       else
-        throwError "Neither a .cabal file nor a package.yaml found under ${path}";
+        throwError "No .cabal file found under ${path}";
   };
 in
 {

nix/haskell-parsers/parser.nix

@@ -32,18 +32,6 @@ in
     in
     parsec.runParser parser cabalProjectFile;
 
-  # Extract the "name" field from a package.yaml file.
-  parsePackageYamlName = packageYamlFile:
-    let
-      spaces1 = parsec.skipWhile1 (c: c == " " || c == "\t");
-      key = parsec.string "name:";
-      val = parsec.fmap lib.concatStrings (parsec.many1 (parsec.anyCharBut "\n"));
-      parser = parsec.skipThen
-        (parsec.skipThen key spaces1)
-        val;
-    in
-    parsec.runParser parser packageYamlFile;
-
   # Extract all the executables from a .cabal file 
   parseCabalExecutableNames = cabalFile:
     with parsec;

nix/haskell-parsers/parser_tests.nix

@@ -18,20 +18,6 @@ let
         expected = [ "foo" "bar" ];
       };
     };
-  packageYamlTests =
-    let
-      eval = s:
-        let res = parser.parsePackageYamlName s; in
-        if res.type == "success" then res.value else res;
-    in
-    {
-      testSimple = {
-        expr = eval ''
-          name: foo
-        '';
-        expected = "foo";
-      };
-    };
   cabalExecutableTests =
     let
       eval = s:
@@ -68,6 +54,5 @@ let
 in
 {
   "cabal.project" = runTestsFailing cabalProjectTests;
-  "package.yaml" = runTestsFailing packageYamlTests;
   "foo-bar.cabal" = runTestsFailing cabalExecutableTests;
 }

runtest.sh

@@ -11,7 +11,6 @@ TESTS=(
   ./nix/haskell-parsers
   ./example
   ./test/simple
-  ./test/hpack
   ./test/with-subdir
   ./test/project-module
   ./doc

test/README.md

@@ -5,7 +5,6 @@ The following tests are available:
 | Directory | Description |
 | --- | --- |
 | `simple/` | Basic functionalities |
-| `hpack` | `hpack` support |
 | `with-subdir` | Prevent redundant rebuilds when parent contents change |
 | `project-module`| Default project modules are generated correctly |
 

test/hpack/flake.nix

@@ -1,22 +0,0 @@
-{
-  # Since there is no flake.lock file (to avoid incongruent haskell-flake
-  # pinning), we must specify revisions for *all* inputs to ensure
-  # reproducibility.
-  inputs = {
-    nixpkgs = { };
-    flake-parts = { };
-    haskell-flake = { };
-  };
-  outputs = inputs@{ self, nixpkgs, flake-parts, ... }:
-    flake-parts.lib.mkFlake { inherit inputs; } {
-      systems = nixpkgs.lib.systems.flakeExposed;
-      imports = [
-        inputs.haskell-flake.flakeModule
-      ];
-      perSystem = { self', pkgs, ... }: {
-        haskellProjects.default = { };
-        # haskell-flake doesn't set the default package, but you can do it here.
-        packages.default = self'.packages.haskell-flake-test;
-      };
-    };
-}

test/hpack/package.yaml

@@ -1,17 +0,0 @@
-name: haskell-flake-test
-version:         0.1.0.0
-license:         NONE
-author:          Joe
-maintainer:      joe@example.com
-
-ghc-options:
-  - -Wall
-
-default-language: Haskell2010
-
-executables:
-  haskell-flake-test:
-    main:          Main.hs
-    dependencies:    
-      - base
-    source-dirs:   src

test/hpack/src/Main.hs

@@ -1,5 +0,0 @@
-module Main where
-
-main :: IO ()
-main = do 
-  putStrLn "Hello world, from hpack test"

test/hpack/test.sh

@@ -1,9 +0,0 @@
-source ../common.sh
-set -euxo pipefail
-
-# First, build the flake
-logHeader "Testing nix build"
-nix build ${OVERRIDE_ALL}
-# Run the devshell test script in a nix develop shell.
-logHeader "Testing nix devshell"
-nix develop ${OVERRIDE_ALL} -c echo