chore(internal/serviceconfig): add default api short name (#4064)

Add default API short name from service name. 

For #3617

Author: JoeWang1127

internal/serviceconfig/serviceconfig.go

@@ -171,14 +171,17 @@ func findServiceConfig(googleapisDir, path string) (string, error) {
 }
 
 func populateFromServiceConfig(api *API, cfg *Service) *API {
-	if api.Title == "" {
-		api.Title = cfg.GetTitle()
+	if api.Description == "" && cfg.GetDocumentation() != nil {
+		api.Description = strings.TrimSpace(cfg.GetDocumentation().GetSummary())
 	}
 	if api.ServiceName == "" {
 		api.ServiceName = cfg.GetName()
 	}
-	if api.Description == "" && cfg.GetDocumentation() != nil {
-		api.Description = strings.TrimSpace(cfg.GetDocumentation().GetSummary())
+	if api.ShortName == "" {
+		api.ShortName = defaultShortName(api.ServiceName)
+	}
+	if api.Title == "" {
+		api.Title = cfg.GetTitle()
 	}
 	publishing := cfg.GetPublishing()
 	if publishing != nil {
@@ -238,6 +241,11 @@ func isServiceConfigFile(path string) (bool, error) {
 	return false, scanner.Err()
 }
 
+// defaultShortName returns the default short name from serviceName.
+func defaultShortName(serviceName string) string {
+	return strings.Split(serviceName, ".")[0]
+}
+
 // FindGRPCServiceConfig searches for gRPC service config files in the given
 // API directory. It returns the path relative to googleapisDir for use with
 // protoc's retry-config option. Returns empty string if no config is found.

internal/serviceconfig/serviceconfig_test.go

@@ -126,6 +126,7 @@ func TestFind(t *testing.T) {
 				Path:          "google/cloud/aiplatform/v1/schema/predict/instance",
 				ServiceConfig: "google/cloud/aiplatform/v1/schema/aiplatform_v1.yaml",
 				ServiceName:   "aiplatform.googleapis.com",
+				ShortName:     "aiplatform",
 				Title:         "Vertex AI API",
 				Transports:    map[string]Transport{"python": "grpc"},
 			},
@@ -149,10 +150,11 @@ func TestFind(t *testing.T) {
 			name: "discovery",
 			api:  "discoveries/compute.v1.json",
 			want: &API{
-				Path:          "google/cloud/compute/v1",
 				Discovery:     "discoveries/compute.v1.json",
+				Path:          "google/cloud/compute/v1",
 				ServiceConfig: "google/cloud/compute/v1/compute_v1.yaml",
 				ServiceName:   "compute.googleapis.com",
+				ShortName:     "compute",
 				Title:         "Google Compute Engine API",
 				Transports:    map[string]Transport{"csharp": "rest", "go": "rest", "java": "rest", "php": "rest"},
 			},
@@ -287,6 +289,17 @@ func TestPopulateFromServiceConfig(t *testing.T) {
 				ShortName:        "override short name",
 			},
 		},
+		{
+			name: "default short name",
+			api:  &API{},
+			cfg: &Service{
+				Name: "accessapproval.googleapis.com",
+			},
+			want: &API{
+				ServiceName: "accessapproval.googleapis.com",
+				ShortName:   "accessapproval",
+			},
+		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			got := populateFromServiceConfig(test.api, test.cfg)