fix(internal/librariangen): test for error path with flags (#12830)

jskeet · web-flow · commit f0da7b22488b · 2025-09-09T16:21:48.000-06:00
fixes: googleapis/librarian#1960
diff --git a/internal/librariangen/main.go b/internal/librariangen/main.go
@@ -91,7 +91,7 @@ func run(ctx context.Context, args []string) error {
 // handleGenerate parses flags for the generate command and calls the generator.
 func handleGenerate(ctx context.Context, args []string) error {
 	cfg := &generate.Config{}
-	generateFlags := flag.NewFlagSet("generate", flag.ExitOnError)
+	generateFlags := flag.NewFlagSet("generate", flag.ContinueOnError)
 	generateFlags.StringVar(&cfg.LibrarianDir, "librarian", "/librarian", "Path to the librarian-tool input directory. Contains generate-request.json.")
 	generateFlags.StringVar(&cfg.InputDir, "input", "/input", "Path to the .librarian/generator-input directory from the language repository.")
 	generateFlags.StringVar(&cfg.OutputDir, "output", "/output", "Path to the empty directory where librariangen writes its output.")
@@ -106,7 +106,7 @@ func handleGenerate(ctx context.Context, args []string) error {
 // handleReleaseInit parses flags for the release-init command and calls the release tool.
 func handleReleaseInit(ctx context.Context, args []string) error {
 	cfg := &release.Config{}
-	releaseFlags := flag.NewFlagSet("release-init", flag.ExitOnError)
+	releaseFlags := flag.NewFlagSet("release-init", flag.ContinueOnError)
 	releaseFlags.StringVar(&cfg.LibrarianDir, "librarian", "/librarian", "Path to the librarian-tool input directory. Contains release-init-request.json.")
 	releaseFlags.StringVar(&cfg.RepoDir, "repo", "/repo", "Path to the language repository checkout.")
 	releaseFlags.StringVar(&cfg.OutputDir, "output", "/output", "Path to the empty directory where librariangen writes its output.")
@@ -119,7 +119,7 @@ func handleReleaseInit(ctx context.Context, args []string) error {
 // handleBuild parses flags for the build command and calls the builder.
 func handleBuild(ctx context.Context, args []string) error {
 	cfg := &build.Config{}
-	buildFlags := flag.NewFlagSet("build", flag.ExitOnError)
+	buildFlags := flag.NewFlagSet("build", flag.ContinueOnError)
 	buildFlags.StringVar(&cfg.LibrarianDir, "librarian", "/librarian", "Path to the librarian-tool input directory. Contains generate-request.json.")
 	buildFlags.StringVar(&cfg.RepoDir, "repo", "/repo", "Path to the root of the complete language repository.")
 	if err := buildFlags.Parse(args); err != nil {
diff --git a/internal/librariangen/main_test.go b/internal/librariangen/main_test.go
@@ -71,6 +71,11 @@ func TestRun(t *testing.T) {
 			args:    []string{"build", "--repo=.", "--librarian=./.librarian"},
 			wantErr: false,
 		},
+		{
+			name:    "build command with bad flag",
+			args:    []string{"build", "--output=."},
+			wantErr: true,
+		},
 		{
 			name:    "configure command",
 			args:    []string{"configure"},
@@ -86,6 +91,11 @@ func TestRun(t *testing.T) {
 			args:    []string{"generate", "--source=.", "--output=./build_out"},
 			wantErr: false,
 		},
+		{
+			name:    "generate command with bad flag",
+			args:    []string{"generate", "--repo=."},
+			wantErr: true,
+		},
 		{
 			name:    "release-init command no flags",
 			args:    []string{"release-init"},
@@ -96,6 +106,11 @@ func TestRun(t *testing.T) {
 			args:    []string{"release-init", "--repo=.", "--output=./build_out"},
 			wantErr: false,
 		},
+		{
+			name:    "release-init command with bad flag",
+			args:    []string{"release-init", "--source=."},
+			wantErr: true,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
