lib.makeOverridable: preserve constructor override and metadata attributes (#461032) (34b2f670) · Commits · nix / nixpkgs

lib/customisation.nix

+18 −1

Original line number	Diff line number	Diff line
		@@ -156,8 +156,25 @@ rec {
		let
		# Creates a functor with the same arguments as f
		mirrorArgs = mirrorFunctionArgs f;
		# Recover overrider and additional attributes for f
		# When f is a callable attribute set,
		# it may contain its own `f.override` and additional attributes.
		# This helper function recovers those attributes and decorate the overrider.
		recoverMetadata =
		if isAttrs f then
		fDecorated:
		# Preserve additional attributes for f
		f
		// fDecorated
		# Decorate f.override if presented
		// lib.optionalAttrs (f ? override) {
		override = fdrv: makeOverridable (f.override fdrv);
		}
		else
		id;
		decorate = f': recoverMetadata (mirrorArgs f');
		in
		mirrorArgs (
		decorate (
		origArgs:
		let
		result = f origArgs;

+79 −0

Original line number	Diff line number	Diff line
		@@ -203,6 +203,85 @@ runTests {
		};
		};

		testOverridePreserveFunctionMetadata =
		let
		toCallableAttrs = f: setFunctionArgs f (functionArgs f);
		constructDefinition =
		{
		a ? 3,
		}:
		toCallableAttrs (
		{
		b ? 5,
		}:
		{
		inherit a b;
		}
		)
		// {
		inherit a;
		c = 7;
		};
		construct0 = makeOverridable constructDefinition { };
		construct1 = makeOverridable construct0;
		construct0p = construct0.override { a = 11; };
		construct1p = construct1.override { a = 11; };
		in
		{
		expr = {
		construct-metadata = {
		inherit (construct1) a c;
		};
		construct-overridden-metadata = {
		v = construct0p.a;
		inherit (construct1p) a c;
		};
		construct-overridden-result-overrider = {
		result-overriders-exist = mapAttrs (_: f: (f { }) ? override) {
		inherit construct1 construct1p;
		};
		result-overrider-functionality = {
		overridden = {
		inherit ((construct1p { }).override { b = 13; }) a b;
		};
		direct = {
		inherit (construct1p { b = 13; }) a b;
		};
		v = {
		inherit (construct0p { b = 13; }) a b;
		};
		};
		};
		};
		expected = {
		construct-metadata = {
		inherit (construct0) a c;
		};
		construct-overridden-metadata = {
		v = 11;
		inherit (construct0p) a c;
		};
		construct-overridden-result-overrider = {
		result-overriders-exist = {
		construct1 = true;
		construct1p = true;
		};
		result-overrider-functionality = {
		overridden = {
		inherit (construct0p { b = 13; }) a b;
		};
		direct = {
		inherit (construct0p { b = 13; }) a b;
		};
		v = {
		a = 11;
		b = 13;
		};
		};
		};
		};
		};

		testCallPackageWithOverridePreservesArguments =
		let
		f =