Merge pull request #1234 from buildpacks/jkutner/fix-any-stack

Allow wildcard "any" stack

Author: jromero

internal/dist/buildpack_descriptor.go

@@ -52,7 +52,7 @@ func (b *BuildpackDescriptor) EnsureStackSupport(stackID string, providedMixins
 
 func (b *BuildpackDescriptor) findMixinsForStack(stackID string) ([]string, error) {
 	for _, s := range b.Stacks {
-		if s.ID == stackID {
+		if s.ID == stackID || s.ID == "*" {
 			return s.Mixins, nil
 		}
 	}

internal/dist/buildpack_descriptor_test.go

@@ -36,6 +36,22 @@ func testBuildpackDescriptor(t *testing.T, when spec.G, it spec.S) {
 				h.AssertNil(t, bp.EnsureStackSupport("some.stack.id", providedMixins, false))
 			})
 
+			it("works with wildcard stack", func() {
+				bp := dist.BuildpackDescriptor{
+					Info: dist.BuildpackInfo{
+						ID:      "some.buildpack.id",
+						Version: "some.buildpack.version",
+					},
+					Stacks: []dist.Stack{{
+						ID:     "*",
+						Mixins: []string{"mixinA", "build:mixinB", "run:mixinD"},
+					}},
+				}
+
+				providedMixins := []string{"mixinA", "build:mixinB", "mixinC"}
+				h.AssertNil(t, bp.EnsureStackSupport("some.stack.id", providedMixins, false))
+			})
+
 			it("returns an error with any missing (and non-ignored) mixins", func() {
 				bp := dist.BuildpackDescriptor{
 					Info: dist.BuildpackInfo{