test(sidekick): missing config tests (#1626)

Author: coryan

internal/sidekick/internal/config/config.go

@@ -90,11 +90,7 @@ func LoadConfig(language string, source, codec map[string]string) (*Config, erro
 		Source: maps.Clone(source),
 		Codec:  maps.Clone(codec),
 	}
-	config, err := mergeConfigs(rootConfig, argsConfig)
-	if err != nil {
-		return nil, err
-	}
-	return config, nil
+	return mergeConfigs(rootConfig, argsConfig), nil
 }
 
 // LoadRootConfig loads the root configuration file.
@@ -124,10 +120,10 @@ func MergeConfigAndFile(rootConfig *Config, filename string) (*Config, error) {
 	if err != nil {
 		return nil, fmt.Errorf("error reading configuration %s: %w", filename, err)
 	}
-	return mergeConfigs(rootConfig, &local)
+	return mergeConfigs(rootConfig, &local), nil
 }
 
-func mergeConfigs(rootConfig, local *Config) (*Config, error) {
+func mergeConfigs(rootConfig, local *Config) *Config {
 	merged := Config{
 		General: GeneralConfig{
 			Language:            rootConfig.General.Language,
@@ -162,7 +158,7 @@ func mergeConfigs(rootConfig, local *Config) (*Config, error) {
 		merged.Source[k] = v
 	}
 	// Ignore errors reading the top-level file.
-	return &merged, nil
+	return &merged
 }
 
 // UpdateRootConfig updates the root configuration file with the latest SHA from GitHub.

internal/sidekick/internal/config/config_test.go

@@ -82,6 +82,19 @@ func TestLoadConfig(t *testing.T) {
 	}
 }
 
+func TestLoadConfigBadRoot(t *testing.T) {
+	t.Chdir(t.TempDir())
+	err := os.WriteFile(configName, []byte("bad-toml: [ a, 1, "), 0644)
+	if err != nil {
+		t.Fatal(err)
+	}
+	source := map[string]string{"root1": "rv1"}
+	codec := map[string]string{"root2": "rv2"}
+	if _, err = LoadConfig("root-language", source, codec); err == nil {
+		t.Errorf("expected an error when loading a missing file")
+	}
+}
+
 func TestLoadRootConfigOnlyGeneral(t *testing.T) {
 	tempFile, err := os.CreateTemp(t.TempDir(), "root-config-")
 	if err != nil {
@@ -247,6 +260,39 @@ func TestMergeLocalForDocumentationOverrides(t *testing.T) {
 	}
 }
 
+func TestMergeConfigAndFileBadRead(t *testing.T) {
+	root := Config{
+		General: GeneralConfig{
+			Language:            "root-language",
+			SpecificationFormat: "root-specification-format",
+			IgnoredDirectories:  []string{"a", "b"},
+		},
+	}
+
+	filename := path.Join(t.TempDir(), "file-does-not-exist")
+	if _, err := MergeConfigAndFile(&root, filename); err == nil {
+		t.Error("expected read error with missing file")
+	}
+}
+
+func TestMergeConfigAndFileBadContent(t *testing.T) {
+	root := Config{
+		General: GeneralConfig{
+			Language:            "root-language",
+			SpecificationFormat: "root-specification-format",
+			IgnoredDirectories:  []string{"a", "b"},
+		},
+	}
+
+	filename := path.Join(t.TempDir(), configName)
+	if err := os.WriteFile(filename, []byte("bad-toml = [ 1, 2"), 0644); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := MergeConfigAndFile(&root, filename); err == nil {
+		t.Error("expected read error with bad contents")
+	}
+}
+
 func TestMergeIgnoreRootSourceAndServiceConfig(t *testing.T) {
 	root := Config{
 		General: GeneralConfig{