chore(tool/cmd/migrate): add a special output to name mapping (#3826)

Two libraries have special output dir name that can't be calculated
based on API path. Therefore use a map to store the output to name
mapping.

For #3580

Author: JoeWang1127

tool/cmd/migrate/main.go

@@ -55,6 +55,11 @@ var (
 	errFetchSource                 = errors.New("cannot fetch source")
 
 	fetchSource = fetchGoogleapis
+
+	pathToName = map[string]string{
+		"google_cloud_protojson_conformance": "google_cloud_protobuf_test_messages_proto3",
+		"google_cloud_showcase_v1beta1":      "google_cloud_showcase_v1beta1",
+	}
 )
 
 func main() {
@@ -243,9 +248,14 @@ func buildGAPIC(files []string, repoPath string) ([]*config.Library, error) {
 			specificationFormat = "protobuf"
 		}
 
-		// Library name or package name is derived from api path by packageName function in dart package.
-		// However, each library in the librarian configuration should have a name.
-		libraryName := genLibraryName(apiPath)
+		var libraryName string
+		if name, ok := pathToName[filepath.Base(filepath.Dir(file))]; ok {
+			libraryName = name
+		} else {
+			// Library name or package name is derived from api path by packageName function in dart package.
+			// However, each library in the librarian configuration should have a name.
+			libraryName = genLibraryName(apiPath)
+		}
 		lib := &config.Library{
 			Name: libraryName,
 			APIs: []*config.API{

tool/cmd/migrate/main_test.go

@@ -257,6 +257,24 @@ API key as an argument when initializing the client.
 			},
 			want: nil,
 		},
+		{
+			name: "special library dir",
+			files: []string{
+				"testdata/read-sidekick-files/special-dir/google_cloud_protojson_conformance/.sidekick.toml",
+			},
+			want: []*config.Library{
+				{
+					Name: "google_cloud_protobuf_test_messages_proto3",
+					APIs: []*config.API{
+						{
+							Path: "src/google/protobuf",
+						},
+					},
+					Output:              "testdata/read-sidekick-files/special-dir/google_cloud_protojson_conformance",
+					SpecificationFormat: "protobuf",
+				},
+			},
+		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			got, err := buildGAPIC(test.files, test.repoPath)

tool/cmd/migrate/testdata/read-sidekick-files/special-dir/google_cloud_protojson_conformance/.sidekick.toml

@@ -0,0 +1,2 @@
+[general]
+specification-source = 'src/google/protobuf'