core/pkgs/build-support/testers/test-equal-derivation.nix
2024-06-30 09:16:52 +01:00

34 lines
743 B
Nix

{
lib,
runCommand,
emptyFile,
nix-diff,
}:
assertion: a: b:
let
drvA =
builtins.unsafeDiscardOutputDependency
a.drvPath or (throw "testEqualDerivation second argument must be a package");
drvB =
builtins.unsafeDiscardOutputDependency
b.drvPath or (throw "testEqualDerivation third argument must be a package");
name = if a ? name then "testEqualDerivation-${a.name}" else "testEqualDerivation";
in
if drvA == drvB then
emptyFile
else
runCommand name
{
inherit assertion drvA drvB;
nativeBuildInputs = [ nix-diff ];
}
''
echo "$assertion"
echo "However, the derivations differ:"
echo
echo nix-diff $drvA $drvB
nix-diff $drvA $drvB
exit 1
''