tests.coq.overrideCoqDerivation: add test

pkgs/test/coq/default.nix

@@ -0,0 +1,6 @@
+{ lib, callPackage }:
+
+lib.recurseIntoAttrs {
+  overrideCoqDerivation = callPackage ./overrideCoqDerivation { };
+}
+

pkgs/test/coq/overrideCoqDerivation/default.nix

@@ -0,0 +1,40 @@
+{ lib, coq, mkCoqPackages, runCommandNoCC }:
+
+let
+
+  # This is just coq, but with dontFilter set to true. We need to set
+  # dontFilter to true here so that _all_ packages are visibile in coqPackages.
+  # There may be some versions of the top-level coq and coqPackages that don't
+  # build QuickChick, which is what we are using for this test below.
+  coqWithAllPackages = coq // { dontFilter = true; };
+
+  coqPackages = mkCoqPackages coqWithAllPackages;
+
+  # This is the main test.  This uses overrideCoqDerivation to
+  # override arguments to mkCoqDerivation.
+  #
+  # Here, we override the defaultVersion and release arguments to
+  # mkCoqDerivation.
+  overriddenQuickChick =
+    coqPackages.lib.overrideCoqDerivation
+      {
+        defaultVersion = "9999";
+        release."9999".sha256 = lib.fakeSha256;
+      }
+      coqPackages.QuickChick;
+in
+
+runCommandNoCC
+  "coq-overrideCoqDerivation-test-0.1"
+  { meta.maintainers = with lib.maintainers; [cdepillabout]; }
+  ''
+    # Confirm that the computed version number for the overridden QuickChick does
+    # actually become 9999, as set above.
+    if [ "${overriddenQuickChick.version}" -eq "9999" ]; then
+      echo "overriddenQuickChick version was successfully set to 9999"
+      touch $out
+    else
+      echo "ERROR: overriddenQuickChick version was supposed to be 9999, but was actually: ${overriddenQuickChick.version}"
+      exit 1
+    fi
+  ''

pkgs/test/default.nix

@@ -75,6 +75,8 @@ with pkgs;
 
   dhall = callPackage ./dhall { };
 
+  coq = callPackage ./coq {};
+
   makeWrapper = callPackage ./make-wrapper { };
   makeBinaryWrapper = callPackage ./make-binary-wrapper {
     makeBinaryWrapper = pkgs.makeBinaryWrapper.override {