Switch to Nix flakes; make the tests pass with newest ArrayFire (#55)

* Switch to Nix flakes; make the tests pass with nix build & nix develop for the latest version of ArrayFire

* update flake.lock

Author: twesterhout

arrayfire.cabal

@@ -21,6 +21,11 @@ flag disable-default-paths
     default:        False
     manual:         True
 
+flag disable-build-tool-depends
+    description:    When enabled, don't add build-tool-depends fields to the Cabal file. Needed for working inside @nix develop@.
+    default:        False
+    manual:         True
+
 custom-setup
  setup-depends:
    base <5,
@@ -75,8 +80,9 @@ library
     ArrayFire.Internal.Types
     ArrayFire.Internal.Util
     ArrayFire.Internal.Vision
-  build-tool-depends:
-    hsc2hs:hsc2hs
+  if !flag(disable-build-tool-depends)
+    build-tool-depends:
+      hsc2hs:hsc2hs
   extra-libraries:
     af
   c-sources:
@@ -148,8 +154,9 @@ test-suite test
     QuickCheck,
     quickcheck-classes,
     vector
-  build-tool-depends:
-    hspec-discover:hspec-discover
+  if !flag(disable-build-tool-depends)
+    build-tool-depends:
+      hspec-discover:hspec-discover
   default-language:
     Haskell2010
   other-modules:

cabal.project

@@ -0,0 +1,5 @@
+ignore-project: False
+write-ghc-environment-files: always
+tests: True
+test-options: "--color"
+test-show-details: streaming

flake.lock

@@ -0,0 +1,90 @@
+{
+  description = "arrayfire/arrayfire-haskell: ArrayFire Haskell bindings";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    nix-filter.url = "github:numtide/nix-filter";
+    arrayfire-nix = {
+      url = "github:twesterhout/arrayfire-nix";
+      inputs.flake-utils.follows = "flake-utils";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = inputs:
+    let
+      src = inputs.nix-filter.lib {
+        root = ./.;
+        include = [
+          "cbits"
+          "exe"
+          "gen"
+          "include"
+          "src"
+          "test"
+          "arrayfire.cabal"
+          "README.md"
+          "CHANGELOG.md"
+          "LICENSE"
+        ];
+      };
+
+      # An overlay that lets us test arrayfire-haskell with different GHC versions
+      arrayfire-haskell-overlay = self: super: {
+        haskell = super.haskell // {
+          packageOverrides = inputs.nixpkgs.lib.composeExtensions super.haskell.packageOverrides
+            (hself: hsuper: {
+              arrayfire = self.haskell.lib.appendConfigureFlags
+                (hself.callCabal2nix "arrayfire" src { af = self.arrayfire; })
+                [ "-f disable-default-paths" ];
+            });
+        };
+      };
+
+      devShell-for = pkgs:
+        let
+          ps = pkgs.haskellPackages;
+        in
+        ps.shellFor {
+          packages = ps: with ps; [ arrayfire ];
+          withHoogle = true;
+          buildInputs = with pkgs; [ ocl-icd ];
+          nativeBuildInputs = with pkgs; with ps; [
+            # Building and testing
+            cabal-install
+            doctest
+            hsc2hs
+            hspec-discover
+            # Language servers
+            haskell-language-server
+            nil
+            # Formatters
+            nixpkgs-fmt
+          ];
+          shellHook = ''
+          '';
+        };
+
+      pkgs-for = system: import inputs.nixpkgs {
+        inherit system;
+        overlays = [
+          inputs.arrayfire-nix.overlays.default
+          arrayfire-haskell-overlay
+        ];
+      };
+    in
+    {
+      packages = inputs.flake-utils.lib.eachDefaultSystemMap (system:
+        with (pkgs-for system); {
+          default = haskellPackages.arrayfire;
+          haskell = haskell.packages;
+        });
+
+      devShells = inputs.flake-utils.lib.eachDefaultSystemMap (system: {
+        default = devShell-for (pkgs-for system);
+      });
+
+      overlays.default = arrayfire-haskell-overlay;
+    };
+}

flake.nix

@@ -32,7 +32,7 @@ spec =
     it "Should get version" $ do
       (major, minor, patch) <- A.getVersion
       major `shouldBe` 3
-      minor `shouldBe` 8
+      minor `shouldSatisfy` (>= 8)
       patch `shouldSatisfy` (>= 0)
     it "Should get revision" $ do
       x <- A.getRevision