Add nix-shell tests and unit tests

- The unit tests are for haskellLib functions

- The nix-shell tests are for checking that development environments work.

modules/package.nix

@@ -173,6 +173,9 @@ in {
         type = attrsOf (componentType false);
         default = {};
       };
+      # all = mkOption {
+      #   type = componentType false;
+      # };
     };
 
     name = mkOption {

test/default.nix

@@ -13,10 +13,16 @@ let
   # The new Haskell infra applied to nix representation of Hackage
   haskell = import ../. hackage;
 
+  haskellLib = let hl = import ../lib { inherit lib; haskellLib = hl; }; in hl;
+
 in {
   cabal-simple = callPackage ./cabal-simple { inherit haskell; };
   cabal-22 = callPackage ./cabal-22 { inherit haskell; };
   with-packages = callPackage ./with-packages { inherit haskell; };
+
+  # Run unit tests with: nix-instantiate --eval --strict -A unit
+  # An empty list means success.
+  unit = callPackage ./unit.nix { inherit haskellLib; };
 }
 
 ## possible test cases

test/tests.sh

@@ -0,0 +1,28 @@
+#! /usr/bin/env nix-shell
+#! nix-shell -i bash -p bash jq nix
+
+set -euo pipefail
+
+cd $(dirname $0)
+
+printf "*** Running the nix-build tests...\n" >& 2
+nix-build --no-out-link --keep-going ./default.nix
+echo >& 2
+
+printf "*** Running the unit tests... " >& 2
+res=$(nix-instantiate --eval --json --strict ./default.nix -A unit)
+num_failed=$(jq length <<< "$res")
+if [ $num_failed -eq 0 ]; then
+  printf "PASSED\n" >& 2
+else
+  printf "$num_failed FAILED\n" >& 2
+  jq . <<< "$res"
+  exit 1
+fi
+
+printf "*** Checking that a nix-shell works for cabal...\n" >& 2
+nix-shell --pure ./default.nix \
+    -A with-packages.test-shell \
+    --run "echo CABAL_CONFIG=$CABAL_CONFIG && cd with-packages && cabal new-build"
+
+printf "\n*** Finished\n" >& 2

test/unit.nix

@@ -0,0 +1,50 @@
+{ lib, haskellLib }:
+
+let
+  emptyConfig = {
+    components = {
+       benchmarks = { };
+       exes = { };
+       foreignlibs = { };
+       library = "library";
+       sublibs = { };
+       tests = { };
+    };
+    package.identifier.name = "empty";
+  };
+
+  componentsConfig = {
+    components = {
+       benchmarks = { bbb = "bbb"; };
+       exes = { eee = "eee"; };
+       foreignlibs = { fff = "fff"; };
+       library = "library";
+       sublibs = { };
+       tests = { ttt = "ttt"; };
+    };
+    package.identifier.name = "nnn";
+  };
+
+in
+lib.runTests {
+  test-applyComponents-id = {
+    expr = haskellLib.applyComponents (componentId: component: component) emptyConfig;
+    expected = emptyConfig.components;
+  };
+
+  test-applyComponents-library = {
+    expr = haskellLib.applyComponents (componentId: component: componentId.cname) emptyConfig;
+    expected = emptyConfig.components // { library = "empty"; };
+  };
+
+  test-applyComponents-components = {
+    expr = haskellLib.applyComponents (componentId: component: component) componentsConfig;
+    expected = componentsConfig.components;
+  };
+
+  # testing that the tests work
+  testId = {
+    expr = lib.id 1;
+    expected = 1;
+  };
+}

test/with-packages/default.nix

@@ -32,17 +32,36 @@ in
 
     buildCommand = let
       inherit (packages.test-with-packages.components) library;
+      # inherit (packages.test-with-packages.components) all; # TODO
       inherit (packages.test-with-packages) devEnv;
     in ''
       ########################################################################
       # test with-packages
 
-      printf "checking that package env has the dependencies... " >& 2
+      printf "checking that the package env has the dependencies... " >& 2
       ${devEnv}/bin/runghc ${./Point.hs}
       echo
 
+      # fixme: probably don't want separate derivation for this -- just use all
+      printf "checking that components.library.shell has the dependencies... " >& 2
+      ''${library.shell}/bin/runghc ${./Point.hs}
+      echo
+
+      # printf "checking that components.all.shell has the dependencies... " >& 2
+      # ''${all.shell}/bin/runghc ${./Point.hs}
+      # echo
+
       touch $out
     '';
 
     meta.platforms = platforms.all;
-} // { inherit packages pkgSet; }
+} // {
+  # Used for debugging with nix repl
+  inherit packages pkgSet;
+
+  # Used for testing externally with nix-shell (../tests.sh).
+  # This just adds cabal-install to the existing shell.
+  test-shell = pkgSet.config.hsPkgs.test-with-packages.components.library.overrideAttrs (oldAttrs: {
+    buildInputs = (oldAttrs.buildInputs or []) ++ [ pkgs.cabal-install ];
+  });
+}