build: include elm-test in nix flake check

README.md

@@ -32,7 +32,6 @@ Run `just check` to check everything, or `just test` for the unit tests.
 
 TODO: include these in `nix flake check`:
 
-- elm-test
 - elm-review
 - an elm-format check
 - style checks for all the other files?

flake.nix

@@ -50,6 +50,8 @@
           sourceInfo = self.sourceInfo;
         };
 
+        elmtests = callPackage ./nix/elmtests.nix { inherit testsSrc; };
+
         peekSrc = name: src:
           stdenv.mkDerivation {
             src = src;
@@ -66,7 +68,7 @@
           testsSrc = peekSrc "tests" testsSrc;
           reviewSrc = peekSrc "elm-review" reviewSrc;
         };
-        checks = { inherit built failIfDepsOutOfSync; };
+        checks = { inherit built elmtests failIfDepsOutOfSync; };
         devShells.default = import ./nix/shell.nix { inherit pkgs; };
         apps.default = {
           type = "app";

nix/default.nix

@@ -4,9 +4,7 @@
 # manually replaced the next two lines:
 # { nixpkgs ? <nixpkgs>, config ? { } }:
 # with (import nixpkgs config);
-{ pkgs, minimalElmSrc }:
-with pkgs;
-
+{ elmPackages, lib, pkgs, minimalElmSrc, nodePackages, stdenv }:
 let
   mkDerivation = { srcs ? ./elm/elm-srcs.nix, src, name, srcdir ? "../src"
     , targets ? [ ], registryDat ? ./elm/registry.dat, outputJavaScript ? false

nix/elmtests.nix

@@ -0,0 +1,19 @@
+{ elmPackages, pkgs, stdenv, testsSrc }:
+stdenv.mkDerivation {
+  name = "elm-test-results";
+  src = testsSrc;
+
+  buildInputs = with elmPackages; [ elm elm-test ];
+
+  buildPhase = pkgs.elmPackages.fetchElmDeps {
+    elmPackages = import ./elm/elm-srcs.nix;
+    elmVersion = "0.19.1";
+    registryDat = ./elm/registry.dat;
+  };
+
+  installPhase = ''
+    set -e
+    elm-test
+    echo "passed" > $out
+  '';
+}