postCSS: Improve validation of option 'config'

Author: deining

Diff for: hugolib/filesystems/basefs.go

@@ -209,19 +209,19 @@ func (b *BaseFs) AbsProjectContentDir(filename string) (string, string, error) {
 
 // ResolveJSConfigFile resolves the JS-related config file to a absolute
 // filename. One example of such would be postcss.config.js.
-func (b *BaseFs) ResolveJSConfigFile(name string) string {
+func (b *BaseFs) ResolveJSConfigFile(name string) (string, bool) {
 	// First look in assets/_jsconfig
 	fi, err := b.Assets.Fs.Stat(filepath.Join(files.FolderJSConfig, name))
 	if err == nil {
-		return fi.(hugofs.FileMetaInfo).Meta().Filename
+		return fi.(hugofs.FileMetaInfo).Meta().Filename, fi.IsDir()
 	}
 	// Fall back to the work dir.
 	fi, err = b.Work.Stat(name)
 	if err == nil {
-		return fi.(hugofs.FileMetaInfo).Meta().Filename
+		return fi.(hugofs.FileMetaInfo).Meta().Filename, fi.IsDir()
 	}
 
-	return ""
+	return "", false
 }
 
 // SourceFilesystems contains the different source file systems. These can be

Diff for: internal/js/esbuild/build.go

@@ -55,7 +55,7 @@ func (c *BuildClient) Build(opts Options) (api.BuildResult, error) {
 	opts.OutDir = c.rs.AbsPublishDir
 	opts.ResolveDir = c.rs.Cfg.BaseConfig().WorkingDir // where node_modules gets resolved
 	opts.AbsWorkingDir = opts.ResolveDir
-	opts.TsConfig = c.rs.ResolveJSConfigFile("tsconfig.json")
+	opts.TsConfig, _ = c.rs.ResolveJSConfigFile("tsconfig.json")
 	assetsResolver := newFSResolver(c.rs.Assets.Fs)
 
 	if err := opts.validate(); err != nil {

Diff for: resources/resource_transformers/babel/babel.go

@@ -134,13 +134,19 @@ func (t *babelTransformation) Transform(ctx *resources.ResourceTransformationCtx
 	}
 
 	configFile = filepath.Clean(configFile)
+	isConfigFileDir := false
 
 	// We need an absolute filename to the config file.
 	if !filepath.IsAbs(configFile) {
-		configFile = t.rs.BaseFs.ResolveJSConfigFile(configFile)
-		if configFile == "" && t.options.Config != "" {
-			// Only fail if the user specified config file is not found.
-			return fmt.Errorf("babel config %q not found", configFile)
+		configFile, isConfigFileDir = t.rs.BaseFs.ResolveJSConfigFile(configFile)
+		if t.options.Config != "" {
+			if configFile == "" {
+				// Only fail if the user specified config file is not found.
+				return fmt.Errorf("babel config file %q not found", configFile)
+			}
+			if isConfigFileDir {
+				loggers.Log().Warnf("babel config %q must be a file, not a directory", configFile)
+			}
 		}
 	}
 

Diff for: resources/resource_transformers/cssjs/postcss.go

@@ -157,13 +157,19 @@ func (t *postcssTransformation) Transform(ctx *resources.ResourceTransformationC
 	}
 
 	configFile = filepath.Clean(configFile)
+	isConfigFileDir := false
 
 	// We need an absolute filename to the config file.
 	if !filepath.IsAbs(configFile) {
-		configFile = t.rs.BaseFs.ResolveJSConfigFile(configFile)
-		if configFile == "" && options.Config != "" {
-			// Only fail if the user specified config file is not found.
-			return fmt.Errorf("postcss config %q not found", options.Config)
+		configFile, isConfigFileDir = t.rs.BaseFs.ResolveJSConfigFile(configFile)
+		if options.Config != "" {
+			if configFile == "" {
+				// Only fail if the user specified config file is not found.
+				return fmt.Errorf("postcss config directory %q not found", options.Config)
+			}
+			if !isConfigFileDir {
+				loggers.Log().Warnf("postcss config %q must be a directory", options.Config)
+			}
 		}
 	}