make banner and footer also work for css

CHANGELOG.md

@@ -20,6 +20,40 @@
 
     If you are using esbuild in the browser, you now need to call `esbuild.initialize({ wasmURL })` and wait for the returned promise before calling `esbuild.transform()`. It takes the same options that `esbuild.startService()` used to take. Note that the `esbuild.buildSync()` and `esbuild.transformSync()` APIs still exist when using esbuild in node. Nothing has changed about the synchronous esbuild APIs.
 
+* The banner and footer options are now language-specific ([#712](https://github.com/evanw/esbuild/issues/712))
+
+    The `--banner=` and `--footer=` options now require you to pass the file type:
+
+    * CLI:
+
+        ```
+        esbuild --banner:js=//banner --footer:js=//footer
+        esbuild --banner:css=/*banner*/ --footer:css=/*footer*/
+        ```
+
+    * JavaScript
+
+        ```js
+        esbuild.build({
+          banner: { js: '//banner', css: '/*banner*/' },
+          footer: { js: '//footer', css: '/*footer*/' },
+        })
+        ```
+
+    * Go
+
+        ```go
+        api.Build(api.BuildOptions{
+          Banner: map[string]string{"js": "//banner"},
+          Footer: map[string]string{"js": "//footer"},
+        })
+        api.Build(api.BuildOptions{
+          Banner: map[string]string{"css": "/*banner*/"},
+          Footer: map[string]string{"css": "/*footer*/"},
+        })
+        ```
+
+    This was changed because the feature was originally added in a JavaScript-specific manner, which was an oversight. CSS banners and footers must be separate from JavaScript banners and footers to avoid injecting JavaScript syntax into your CSS files.
 
 ## Unreleased
 

cmd/esbuild/main.go

@@ -45,11 +45,13 @@ var helpText = func(colors logger.Colors) string {
   --watch               Watch mode: rebuild on file system changes
 
 ` + colors.Bold + `Advanced options:` + colors.Default + `
-  --banner=...              Text to be prepended to each output file
+  --banner:T=...            Text to be prepended to each output file of type T
+                            where T is one of: css | js
   --charset=utf8            Do not escape UTF-8 code points
   --color=...               Force use of color terminal escapes (true | false)
   --error-limit=...         Maximum error count or 0 to disable (default 10)
-  --footer=...              Text to be appended to each output file
+  --footer:T=...            Text to be appended to each output file of type T
+                            where T is one of: css | js
   --global-name=...         The name of the global for the IIFE format
   --inject:F                Import the file F into all input files and
                             automatically replace matching globals with imports

internal/bundler/linker.go

@@ -3748,10 +3748,10 @@ func (repr *chunkReprJS) generate(c *linkerContext, chunk *chunkInfo) func(gener
 			}
 		}
 
-		if len(c.options.Banner) > 0 {
-			prevOffset.advanceString(c.options.Banner)
+		if len(c.options.JSBanner) > 0 {
+			prevOffset.advanceString(c.options.JSBanner)
 			prevOffset.advanceString("\n")
-			j.AddString(c.options.Banner)
+			j.AddString(c.options.JSBanner)
 			j.AddString("\n")
 		}
 
@@ -3969,8 +3969,8 @@ func (repr *chunkReprJS) generate(c *linkerContext, chunk *chunkInfo) func(gener
 			j.AddString("\n")
 		}
 
-		if len(c.options.Footer) > 0 {
-			j.AddString(c.options.Footer)
+		if len(c.options.JSFooter) > 0 {
+			j.AddString(c.options.JSFooter)
 			j.AddString("\n")
 		}
 
@@ -4179,6 +4179,11 @@ func (repr *chunkReprCSS) generate(c *linkerContext, chunk *chunkInfo) func(gene
 		j := js_printer.Joiner{}
 		newlineBeforeComment := false
 
+		if len(c.options.CSSBanner) > 0 {
+			j.AddString(c.options.CSSBanner)
+			j.AddString("\n")
+		}
+
 		// Generate any prefix rules now
 		{
 			ast := css_ast.AST{}
@@ -4278,6 +4283,11 @@ func (repr *chunkReprCSS) generate(c *linkerContext, chunk *chunkInfo) func(gene
 			j.AddString("\n")
 		}
 
+		if len(c.options.CSSFooter) > 0 {
+			j.AddString(c.options.CSSFooter)
+			j.AddString("\n")
+		}
+
 		// The CSS contents are done now that the source map comment is in
 		cssContents := j.Done()
 

internal/config/config.go

@@ -217,8 +217,11 @@ type Options struct {
 	InjectAbsPaths     []string
 	InjectedDefines    []InjectedDefine
 	InjectedFiles      []InjectedFile
-	Banner             string
-	Footer             string
+
+	JSBanner  string
+	JSFooter  string
+	CSSBanner string
+	CSSFooter string
 
 	ChunkPathTemplate []PathTemplate
 	AssetPathTemplate []PathTemplate

lib/common.ts

@@ -109,8 +109,6 @@ function pushCommonFlags(flags: string[], options: CommonOptions, keys: OptionKe
   let define = getFlag(options, keys, 'define', mustBeObject);
   let pure = getFlag(options, keys, 'pure', mustBeArray);
   let keepNames = getFlag(options, keys, 'keepNames', mustBeBoolean);
-  let banner = getFlag(options, keys, 'banner', mustBeString);
-  let footer = getFlag(options, keys, 'footer', mustBeString);
 
   if (sourcesContent !== void 0) flags.push(`--sources-content=${sourcesContent}`);
   if (target) {
@@ -137,9 +135,6 @@ function pushCommonFlags(flags: string[], options: CommonOptions, keys: OptionKe
   }
   if (pure) for (let fn of pure) flags.push(`--pure:${fn}`);
   if (keepNames) flags.push(`--keep-names`);
-
-  if (banner) flags.push(`--banner=${banner}`);
-  if (footer) flags.push(`--footer=${footer}`);
 }
 
 function flagsForBuildOptions(
@@ -188,6 +183,8 @@ function flagsForBuildOptions(
   let chunkNames = getFlag(options, keys, 'chunkNames', mustBeString);
   let assetNames = getFlag(options, keys, 'assetNames', mustBeString);
   let inject = getFlag(options, keys, 'inject', mustBeArray);
+  let banner = getFlag(options, keys, 'banner', mustBeObject);
+  let footer = getFlag(options, keys, 'footer', mustBeObject);
   let entryPoints = getFlag(options, keys, 'entryPoints', mustBeArray);
   let absWorkingDir = getFlag(options, keys, 'absWorkingDir', mustBeString);
   let stdin = getFlag(options, keys, 'stdin', mustBeObject);
@@ -239,6 +236,18 @@ function flagsForBuildOptions(
     flags.push(`--main-fields=${values.join(',')}`);
   }
   if (external) for (let name of external) flags.push(`--external:${name}`);
+  if (banner) {
+    for (let type in banner) {
+      if (type.indexOf('=') >= 0) throw new Error(`Invalid banner file type: ${type}`);
+      flags.push(`--banner:${type}=${banner[type]}`);
+    }
+  }
+  if (footer) {
+    for (let type in footer) {
+      if (type.indexOf('=') >= 0) throw new Error(`Invalid footer file type: ${type}`);
+      flags.push(`--footer:${type}=${footer[type]}`);
+    }
+  }
   if (inject) for (let path of inject) flags.push(`--inject:${path}`);
   if (loader) {
     for (let ext in loader) {
@@ -311,12 +320,16 @@ function flagsForTransformOptions(
   let tsconfigRaw = getFlag(options, keys, 'tsconfigRaw', mustBeStringOrObject);
   let sourcefile = getFlag(options, keys, 'sourcefile', mustBeString);
   let loader = getFlag(options, keys, 'loader', mustBeString);
+  let banner = getFlag(options, keys, 'banner', mustBeString);
+  let footer = getFlag(options, keys, 'footer', mustBeString);
   checkForInvalidFlags(options, keys, `in ${callName}() call`);
 
   if (sourcemap) flags.push(`--sourcemap=${sourcemap === true ? 'external' : sourcemap}`);
   if (tsconfigRaw) flags.push(`--tsconfig-raw=${typeof tsconfigRaw === 'string' ? tsconfigRaw : JSON.stringify(tsconfigRaw)}`);
   if (sourcefile) flags.push(`--sourcefile=${sourcefile}`);
   if (loader) flags.push(`--loader=${loader}`);
+  if (banner) flags.push(`--banner=${banner}`);
+  if (footer) flags.push(`--footer=${footer}`);
 
   return flags;
 }

lib/types.ts

@@ -25,8 +25,6 @@ interface CommonOptions {
   define?: { [key: string]: string };
   pure?: string[];
   keepNames?: boolean;
-  banner?: string;
-  footer?: string;
 
   color?: boolean;
   logLevel?: LogLevel;
@@ -53,6 +51,8 @@ export interface BuildOptions extends CommonOptions {
   chunkNames?: string;
   assetNames?: string;
   inject?: string[];
+  banner?: { [type: string]: string };
+  footer?: { [type: string]: string };
   incremental?: boolean;
   entryPoints?: string[];
   stdin?: StdinOptions;
@@ -158,6 +158,8 @@ export interface TransformOptions extends CommonOptions {
 
   sourcefile?: string;
   loader?: Loader;
+  banner?: string;
+  footer?: string;
 }
 
 export interface TransformResult {

pkg/api/api.go

@@ -260,8 +260,8 @@ type BuildOptions struct {
 	OutExtensions     map[string]string
 	PublicPath        string
 	Inject            []string
-	Banner            string
-	Footer            string
+	Banner            map[string]string
+	Footer            map[string]string
 	NodePaths         []string // The "NODE_PATH" variable from Node.js
 
 	ChunkNames string

pkg/api/api_impl.go

@@ -503,6 +503,20 @@ func validateOutputExtensions(log logger.Log, outExtensions map[string]string) (
 	return
 }
 
+func validateBannerOrFooter(log logger.Log, name string, values map[string]string) (js string, css string) {
+	for key, value := range values {
+		switch key {
+		case "js":
+			js = value
+		case "css":
+			css = value
+		default:
+			log.AddError(nil, logger.Loc{}, fmt.Sprintf("Invalid %s file type: %q (valid: css, js)", name, key))
+		}
+	}
+	return
+}
+
 func convertLocationToPublic(loc *logger.MsgLocation) *Location {
 	if loc != nil {
 		return &Location{
@@ -685,6 +699,8 @@ func rebuildImpl(
 	}
 	jsFeatures, cssFeatures := validateFeatures(log, buildOpts.Target, buildOpts.Engines)
 	outJS, outCSS := validateOutputExtensions(log, buildOpts.OutExtensions)
+	bannerJS, bannerCSS := validateBannerOrFooter(log, "banner", buildOpts.Banner)
+	footerJS, footerCSS := validateBannerOrFooter(log, "footer", buildOpts.Footer)
 	defines, injectedDefines := validateDefines(log, buildOpts.Define, buildOpts.Pure)
 	options := config.Options{
 		UnsupportedJSFeatures:  jsFeatures,
@@ -723,8 +739,10 @@ func rebuildImpl(
 		KeepNames:             buildOpts.KeepNames,
 		InjectAbsPaths:        make([]string, len(buildOpts.Inject)),
 		AbsNodePaths:          make([]string, len(buildOpts.NodePaths)),
-		Banner:                buildOpts.Banner,
-		Footer:                buildOpts.Footer,
+		JSBanner:              bannerJS,
+		JSFooter:              footerJS,
+		CSSBanner:             bannerCSS,
+		CSSFooter:             footerCSS,
 		PreserveSymlinks:      buildOpts.PreserveSymlinks,
 		WatchMode:             buildOpts.Watch != nil,
 		Plugins:               plugins,
@@ -1157,8 +1175,13 @@ func transformImpl(input string, transformOpts TransformOptions) TransformResult
 			Contents:   input,
 			SourceFile: transformOpts.Sourcefile,
 		},
-		Banner: transformOpts.Banner,
-		Footer: transformOpts.Footer,
+	}
+	if options.Stdin.Loader == config.LoaderCSS {
+		options.CSSBanner = transformOpts.Banner
+		options.CSSFooter = transformOpts.Footer
+	} else {
+		options.JSBanner = transformOpts.Banner
+		options.JSFooter = transformOpts.Footer
 	}
 	if options.SourceMap == config.SourceMapLinkedWithComment {
 		// Linked source maps don't make sense because there's no output file name

pkg/cli/cli_impl.go

@@ -19,6 +19,8 @@ func newBuildOptions() api.BuildOptions {
 	return api.BuildOptions{
 		Loader: make(map[string]api.Loader),
 		Define: make(map[string]string),
+		Banner: make(map[string]string),
+		Footer: make(map[string]string),
 	}
 }
 
@@ -347,21 +349,27 @@ func parseOptionsImpl(osArgs []string, buildOpts *api.BuildOptions, transformOpt
 				transformOpts.JSXFragment = value
 			}
 
-		case strings.HasPrefix(arg, "--banner="):
-			value := arg[len("--banner="):]
-			if buildOpts != nil {
-				buildOpts.Banner = value
-			} else {
-				transformOpts.Banner = value
+		case strings.HasPrefix(arg, "--banner=") && transformOpts != nil:
+			transformOpts.Banner = arg[len("--banner="):]
+
+		case strings.HasPrefix(arg, "--footer=") && transformOpts != nil:
+			transformOpts.Footer = arg[len("--footer="):]
+
+		case strings.HasPrefix(arg, "--banner:") && buildOpts != nil:
+			value := arg[len("--banner:"):]
+			equals := strings.IndexByte(value, '=')
+			if equals == -1 {
+				return fmt.Errorf("Missing \"=\": %q", value)
 			}
+			buildOpts.Banner[value[:equals]] = value[equals+1:]
 
-		case strings.HasPrefix(arg, "--footer="):
-			value := arg[len("--footer="):]
-			if buildOpts != nil {
-				buildOpts.Footer = value
-			} else {
-				transformOpts.Footer = value
+		case strings.HasPrefix(arg, "--footer:") && buildOpts != nil:
+			value := arg[len("--footer:"):]
+			equals := strings.IndexByte(value, '=')
+			if equals == -1 {
+				return fmt.Errorf("Missing \"=\": %q", value)
 			}
+			buildOpts.Footer[value[:equals]] = value[equals+1:]
 
 		case strings.HasPrefix(arg, "--error-limit="):
 			value := arg[len("--error-limit="):]

scripts/end-to-end-tests.js

@@ -2706,13 +2706,13 @@
 
   // Test injecting banner and footer
   tests.push(
-    test(['in.js', '--outfile=node.js', '--banner=const bannerDefined = true;'], {
+    test(['in.js', '--outfile=node.js', '--banner:js=const bannerDefined = true;'], {
       'in.js': `if (!bannerDefined) throw 'fail'`
     }),
-    test(['in.js', '--outfile=node.js', '--footer=function footer() { }'], {
+    test(['in.js', '--outfile=node.js', '--footer:js=function footer() { }'], {
       'in.js': `footer()`
     }),
-    test(['a.js', 'b.js', '--outdir=out', '--bundle', '--format=cjs', '--banner=const bannerDefined = true;', '--footer=function footer() { }'], {
+    test(['a.js', 'b.js', '--outdir=out', '--bundle', '--format=cjs', '--banner:js=const bannerDefined = true;', '--footer:js=function footer() { }'], {
       'a.js': `
         module.exports = { banner: bannerDefined, footer };
       `,

scripts/esbuild.js

@@ -144,8 +144,8 @@ exports.buildWasmLib = async (esbuildPath) => {
       '--format=cjs',
       '--define:ESBUILD_VERSION=' + JSON.stringify(version),
       '--define:WEB_WORKER_SOURCE_CODE=' + JSON.stringify(wasmExecCode + workerCode),
-      '--banner=' + umdPrefix,
-      '--footer=' + umdSuffix,
+      '--banner:js=' + umdPrefix,
+      '--footer:js=' + umdSuffix,
       '--log-level=warning',
     ].concat(minifyFlags), { cwd: repoDir }).toString()
     fs.writeFileSync(path.join(libDir, minify ? 'browser.min.js' : 'browser.js'), browserCJS)