chore(internal/librarian): add snippet directories to legacy state (#5137)

The `createLegacyLibrary` function is updated to include the generated
snippets directory in both the `SourceRoots` and `ReleaseExcludePaths`
fields for the legacy configuration.

Snippet directory needs to be present in `SourceRoots` so that the
updated snippet metadata can be copied from docker response to language
repository.

Snippet directory needs to be present in `ReleaseExcludePaths` so that
changes in this directory will cause a release.

See go/sdk-librarian-interim-state for more details.

Fixes #5034

Author: JoeWang1127

internal/librarian/add.go

@@ -252,10 +252,16 @@ func createLegacyLibrary(lib *config.Library) *legacyconfig.LibraryState {
 		libAPIs = append(libAPIs, &legacyconfig.API{Path: api.Path})
 	}
 	return &legacyconfig.LibraryState{
-		ID:          lib.Name,
-		Version:     lib.Version,
-		APIs:        libAPIs,
-		SourceRoots: []string{lib.Name},
-		TagFormat:   "{id}/v{version}",
+		ID:      lib.Name,
+		Version: lib.Version,
+		APIs:    libAPIs,
+		SourceRoots: []string{
+			lib.Name,
+			fmt.Sprintf("internal/generated/snippets/%s", lib.Name),
+		},
+		ReleaseExcludePaths: []string{
+			fmt.Sprintf("internal/generated/snippets/%s/", lib.Name),
+		},
+		TagFormat: "{id}/v{version}",
 	}
 }

internal/librarian/add_test.go

@@ -609,13 +609,14 @@ func TestSyncToStateYAML(t *testing.T) {
 						SourceRoots:   []string{"existing"},
 					},
 					{
-						ID:            "new",
-						Version:       "0.1.0",
-						PreserveRegex: []string{},
-						RemoveRegex:   []string{},
-						APIs:          []*legacyconfig.API{{Path: "google/cloud/new/v1"}},
-						SourceRoots:   []string{"new"},
-						TagFormat:     "{id}/v{version}",
+						ID:                  "new",
+						Version:             "0.1.0",
+						PreserveRegex:       []string{},
+						RemoveRegex:         []string{},
+						APIs:                []*legacyconfig.API{{Path: "google/cloud/new/v1"}},
+						SourceRoots:         []string{"new", "internal/generated/snippets/new"},
+						ReleaseExcludePaths: []string{"internal/generated/snippets/new/"},
+						TagFormat:           "{id}/v{version}",
 					},
 				},
 			},
@@ -636,22 +637,24 @@ func TestSyncToStateYAML(t *testing.T) {
 				Image: "gcr.io/my-image:latest",
 				Libraries: []*legacyconfig.LibraryState{
 					{
-						ID:            "lib-a",
-						Version:       "2.0.0",
-						PreserveRegex: []string{},
-						RemoveRegex:   []string{},
-						APIs:          []*legacyconfig.API{{Path: "google/cloud/lib-a/v1"}},
-						SourceRoots:   []string{"lib-a"},
-						TagFormat:     "{id}/v{version}",
+						ID:                  "lib-a",
+						Version:             "2.0.0",
+						PreserveRegex:       []string{},
+						RemoveRegex:         []string{},
+						APIs:                []*legacyconfig.API{{Path: "google/cloud/lib-a/v1"}},
+						SourceRoots:         []string{"lib-a", "internal/generated/snippets/lib-a"},
+						ReleaseExcludePaths: []string{"internal/generated/snippets/lib-a/"},
+						TagFormat:           "{id}/v{version}",
 					},
 					{
-						ID:            "lib-b",
-						Version:       "1.0.0",
-						PreserveRegex: []string{},
-						RemoveRegex:   []string{},
-						APIs:          []*legacyconfig.API{{Path: "google/cloud/lib-b/v1"}},
-						SourceRoots:   []string{"lib-b"},
-						TagFormat:     "{id}/v{version}",
+						ID:                  "lib-b",
+						Version:             "1.0.0",
+						PreserveRegex:       []string{},
+						RemoveRegex:         []string{},
+						APIs:                []*legacyconfig.API{{Path: "google/cloud/lib-b/v1"}},
+						SourceRoots:         []string{"lib-b", "internal/generated/snippets/lib-b"},
+						ReleaseExcludePaths: []string{"internal/generated/snippets/lib-b/"},
+						TagFormat:           "{id}/v{version}",
 					},
 				},
 			},