Fix up Haskell.nix usage and add Hydra job for coverage

Author: rvl

default.nix

@@ -75,7 +75,7 @@ let
 
   # Creates a development environment for Cabal builds or ghci
   # sessions, with various build tools included.
-  mkShell = name: hsPkgs: hsPkgs.shellFor {
+  mkShell = name: hp: hp.shellFor {
     inherit name;
     packages = ps: attrValues (selectProjectPackages ps);
     buildInputs = (with self; [
@@ -150,12 +150,8 @@ let
     tests = collectComponents "tests" isProjectPackage coveredHaskellPackages;
     # `checks` are the result of executing the tests.
     checks = pkgs.recurseIntoAttrs (getPackageChecks (selectProjectPackages coveredHaskellPackages));
-    # Combined coverage report
-    # fixme: haskell.nix needs to support using `checks` attrset from
-    # above, otherwise we will be running unnecessary test suites.
-    # testCoverageReport = pkgs.haskell-nix.haskellLib.projectCoverageReport {
-    #   packages = selectProjectPackages coveredHaskellPackages;
-    # };
+    # Combined project coverage report
+    inherit (coveredHaskellPackages) testCoverageReport;
     # `benchmarks` are only built, not run.
     benchmarks = collectComponents "benchmarks" isProjectPackage haskellPackages;
 

nix/haskell.nix

@@ -31,7 +31,7 @@ let
   filterSubDir = subDir:
     haskell.haskellLib.cleanSourceWith { inherit src subDir; };
 
-  pkgSet = haskell.mkStackPkgSet {
+  pkg-set = haskell.mkStackPkgSet {
     inherit stack-pkgs;
     modules = [
       # Add source filtering to local packages
@@ -302,10 +302,20 @@ let
       '';
     };
 
+  proj = haskell.addProjectAndPackageAttrs {
+    inherit pkg-set;
+    inherit (pkg-set.config) hsPkgs;
+  };
+
 in
-haskell.addProjectAndPackageAttrs {
-  pkg-set = pkgSet;
-  inherit (pkgSet.config) hsPkgs;
-  _config = pkgSet.config;
-  _roots = haskell.roots pkgSet.config.ghc;
-}
+  proj.hsPkgs // {
+    _config = proj.pkg-set.config;
+    #_roots = haskell.roots proj.pkg-set.config.ghc;
+    testCoverageReport = proj.projectCoverageReport.overrideAttrs (old: {
+      buildCommand = old.buildCommand + ''
+        mkdir -p $out/nix-support
+        echo "report coverage $out/share/hpc/vanilla/html/all/hpc_index.html" >> $out/nix-support/hydra-build-products
+        echo "report coverage-per-package $out/share/hpc/vanilla/html/index.html" >> $out/nix-support/hydra-build-products
+      '';
+    });
+  }