[Stimulus] Detect the lazy marker inside preserved /*! ... */ comments

Port symfony/ux#3702: recognise `stimulusFetch: 'lazy'` when it sits inside a
preserved `/*! ... */` block comment, the form tsc/esbuild keep so the marker
survives minification. Only the `/*` branch of the regex gains the optional `!`.

Author: Kocal

assets/src/core/stimulus.ts

@@ -54,8 +54,10 @@ interface ResolvedController {
 // which is why a stray `stimulusFetch: 'lazy'` sitting above the imports (or anywhere else) does
 // NOT flip the controller to lazy. It may be a block comment or a single-line one, single or
 // double quotes; a block comment may sit on the class's own line, a line comment must precede it.
+// A preserved block comment (`/*! ... */`, the form tsc/esbuild keep so the marker survives
+// minification) is recognised too.
 const LAZY_COMMENT_RE =
-    /(?:\/\*\s*stimulusFetch:\s*['"]lazy['"]\s*\*\/|\/\/\s*stimulusFetch:\s*['"]lazy['"])\s*(?:export\s+(?:default\s+)?)?(?:abstract\s+)?class\b/i;
+    /(?:\/\*!?\s*stimulusFetch:\s*['"]lazy['"]\s*\*\/|\/\/\s*stimulusFetch:\s*['"]lazy['"])\s*(?:export\s+(?:default\s+)?)?(?:abstract\s+)?class\b/i;
 const LOCAL_CONTROLLER_RE = /[-_]controller\.[jt]s$/;
 
 export function generateControllersModule(opts: ResolvedStimulusOptions, root: string, isDev: boolean): string {

assets/test/core/stimulus.test.ts

@@ -59,6 +59,13 @@ describe('generateControllersModule — local', () => {
         expect(src).toContain(posix(join(root, 'controllers/single_line_controller.js')));
     });
 
+    it('detects the lazy marker inside a preserved /*! ... */ comment', () => {
+        const src = generateControllersModule(localOpts, root, false);
+        // tsc/esbuild keep `/*! ... */` comments through minification, so the marker survives.
+        expect(src).toContain(`"preserved-comment": () => import(`);
+        expect(src).toContain(posix(join(root, 'controllers/preserved_comment_controller.js')));
+    });
+
     it('ignores a lazy marker that sits above the imports (it must be directly above the class)', () => {
         const src = generateControllersModule(localOpts, root, false);
         // The marker in `above_imports_controller.js` precedes the imports, not the class,
@@ -78,6 +85,7 @@ describe('generateControllersModule — local', () => {
         expect(src).toContain('export const eagerControllers = {}');
         expect(src).toContain('export const lazyControllers = {}');
     });
+
 });
 
 describe('generateControllersModule — identifier collision', () => {

assets/test/fixtures/stimulus/controllers/preserved_comment_controller.js

@@ -0,0 +1,2 @@
+/*! stimulusFetch: 'lazy' */
+export default class {}

doc/index.rst

@@ -119,7 +119,9 @@ imports) — a block or a single-line comment both work:
     /* stimulusFetch: 'lazy' */
     export default class extends Controller {}
 
-(``// stimulusFetch: 'lazy'`` on the line above the class works too.)
+(``// stimulusFetch: 'lazy'`` on the line above the class works too, as does a
+preserved ``/*! stimulusFetch: 'lazy' */`` comment — the form tsc and esbuild keep
+through minification.)
 
 **Third-party UX packages.** Controllers declared in ``controllers.json`` are
 resolved from ``node_modules``, so install them with your package manager, the