fix(hmr): split component ids on the last @

crates/oxc_angular_compiler/src/hmr/update_module.rs

@@ -94,8 +94,9 @@ pub fn generate_hmr_update_module_from_js(
     declarations_js: Option<&str>,
     consts_js: Option<&str>,
 ) -> String {
-    // Extract class name from component_id (format: "path@ClassName")
-    let class_name = component_id.split('@').nth(1).unwrap_or("Component");
+    // Extract class name from component_id (format: "path@ClassName"). The path
+    // can contain `@` (e.g. `node_modules/@scope/...`) but a class name cannot.
+    let class_name = component_id.rsplit_once('@').map_or("Component", |(_, name)| name);
 
     generate_hmr_update_module_internal(
         component_id,
@@ -270,6 +271,23 @@ mod tests {
         assert!(result.contains("function MyComponent_UpdateMetadata(MyComponent"));
     }
 
+    #[test]
+    fn test_class_name_extraction_path_with_at() {
+        for id in
+            ["node_modules/@scope/pkg/src/a.ts@MyComponent", "packages/@a/@b/x.ts@MyComponent"]
+        {
+            let result = generate_hmr_update_module_from_js(id, "", None, None, None);
+            assert!(result.contains("function MyComponent_UpdateMetadata(MyComponent"), "{id}");
+            assert!(result.contains("MyComponent.ɵcmp ="), "{id}");
+        }
+    }
+
+    #[test]
+    fn test_class_name_extraction_no_at_falls_back() {
+        let result = generate_hmr_update_module_from_js("MyComponent", "", None, None, None);
+        assert!(result.contains("function Component_UpdateMetadata(Component"));
+    }
+
     #[test]
     fn test_generate_hmr_update_module_with_declarations() {
         let declarations = "function App_For_1(rf, ctx) { }\nconst _c0 = [1, 2, 3];";

napi/angular-compiler/src/lib.rs

@@ -20,14 +20,14 @@ use napi_derive::napi;
 use oxc_allocator::Allocator;
 use oxc_angular_compiler::{
     AngularVersion as RustAngularVersion, ChangeDetectionStrategy as RustChangeDetectionStrategy,
-    HostMetadataInput as RustHostMetadataInput, TransformOptions as RustTransformOptions,
-    ViewEncapsulation as RustViewEncapsulation,
+    HmrUpdateModuleOptions, HostMetadataInput as RustHostMetadataInput,
+    TransformOptions as RustTransformOptions, ViewEncapsulation as RustViewEncapsulation,
     build_ctor_params_metadata as core_build_ctor_params_metadata,
     build_decorator_metadata_array as core_build_decorator_metadata_array,
     build_prop_decorators_metadata as core_build_prop_decorators_metadata,
     compile_template_for_hmr, compile_template_to_js_with_options,
-    encapsulate_style as rust_encapsulate_style, generate_hmr_update_module_from_js,
-    generate_style_update_module,
+    encapsulate_style as rust_encapsulate_style, generate_hmr_update_module,
+    generate_hmr_update_module_from_js, generate_style_update_module,
 };
 use oxc_napi::OxcError;
 
@@ -595,13 +595,15 @@ pub fn compile_for_hmr_sync(
                 };
 
             // Generate HMR module with declarations, encapsulated styles, and consts
-            let hmr_module = generate_hmr_update_module_from_js(
-                &component_id,
-                &template_js,
-                encapsulated_styles.as_deref(),
+            let hmr_module = generate_hmr_update_module(&HmrUpdateModuleOptions {
+                component_id: &component_id,
+                class_name: &component_name,
+                template_js: Some(&template_js),
+                styles: encapsulated_styles.as_deref(),
                 declarations_js,
-                output.consts_js.as_deref(),
-            );
+                consts_js: output.consts_js.as_deref(),
+                include_full_metadata: false,
+            });
 
             HmrCompileResult { hmr_module, component_id, template_js, errors: vec![] }
         }

napi/angular-compiler/test/hmr-hot-update.test.ts

@@ -16,7 +16,7 @@ import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 
 import type { Plugin, ModuleNode, HmrContext } from 'vite'
-import { normalizePath, resolveConfig } from 'vite'
+import { normalizePath, parseSync, resolveConfig } from 'vite'
 import { afterAll, beforeAll, describe, it, expect, vi } from 'vitest'
 
 import { angular } from '../vite-plugin/index.js'
@@ -383,6 +383,40 @@ describe('pendingHmrUpdates race condition', () => {
     expect(bBody).toContain('BComponent')
   })
 
+  it('serves the HMR module for a component whose path contains @', async () => {
+    const plugin = getAngularPlugin()
+    const mockServer = await setupPluginWithServer(plugin)
+
+    const scopedDir = join(tempDir, 'packages', '@company', 'app')
+    mkdirSync(scopedDir, { recursive: true })
+    const scopedPath = join(scopedDir, 'scoped.component.ts')
+    const source = `
+      import { Component } from '@angular/core';
+      @Component({ selector: 'app-scoped', template: '<p>S</p>' })
+      export class ScopedComponent {}
+    `
+    writeFileSync(scopedPath, source)
+
+    if (!plugin.transform || typeof plugin.transform === 'function') {
+      throw new Error('Expected plugin transform handler')
+    }
+    await plugin.transform.handler.call(
+      { error() {}, warn() {}, addWatchFile() {} } as any,
+      source,
+      scopedPath,
+    )
+
+    writeFileSync(scopedPath, source.replace('<p>S</p>', '<p>S!</p>'))
+    const ctx = createMockHmrContext(scopedPath, [{ id: scopedPath }], mockServer)
+    await callHandleHotUpdate(plugin, ctx)
+
+    const middleware = (mockServer.middlewares.use as ReturnType<typeof vi.fn>).mock.calls[0]?.[0]
+    const body = await invokeAngularMiddleware(middleware, `${scopedPath}@ScopedComponent`)
+
+    expect(body).toContain('function ScopedComponent_UpdateMetadata(ScopedComponent')
+    expect(parseSync('hmr.js', body).errors).toEqual([])
+  })
+
   it("dispatches HMR for both components when only one component's inline styles change", async () => {
     const plugin = getAngularPlugin()
     const mockServer = await setupPluginWithServer(plugin)
@@ -527,6 +561,55 @@ describe('pendingHmrUpdates race condition', () => {
     expect(dropBody2).toBe('')
   })
 
+  it('prunes only the removed class when the file path contains @', async () => {
+    const plugin = getAngularPlugin()
+    const mockServer = await setupPluginWithServer(plugin)
+
+    const scopedDir = join(tempDir, 'packages', '@company', 'prune')
+    mkdirSync(scopedDir, { recursive: true })
+    const stalePath = join(scopedDir, 'stale.component.ts')
+    const originalSource = `
+      import { Component } from '@angular/core';
+      @Component({ selector: 'app-keep', template: '<keep/>' })
+      export class KeepComponent {}
+      @Component({ selector: 'app-drop', template: '<drop/>' })
+      export class DropComponent {}
+    `
+    writeFileSync(stalePath, originalSource)
+
+    if (!plugin.transform || typeof plugin.transform === 'function') {
+      throw new Error('Expected plugin transform handler')
+    }
+    await plugin.transform.handler.call(
+      { error() {}, warn() {}, addWatchFile() {} } as any,
+      originalSource,
+      stalePath,
+    )
+
+    writeFileSync(stalePath, originalSource.replace('<keep/>', '<keep-edited/>'))
+    const ctx = createMockHmrContext(stalePath, [{ id: stalePath }], mockServer)
+    await callHandleHotUpdate(plugin, ctx)
+
+    const reducedSource = `
+      import { Component } from '@angular/core';
+      @Component({ selector: 'app-keep', template: '<keep-edited/>' })
+      export class KeepComponent {}
+    `
+    writeFileSync(stalePath, reducedSource)
+    await plugin.transform.handler.call(
+      { error() {}, warn() {}, addWatchFile() {} } as any,
+      reducedSource,
+      stalePath,
+    )
+
+    const middleware = (mockServer.middlewares.use as ReturnType<typeof vi.fn>).mock.calls[0]?.[0]
+
+    expect(await invokeAngularMiddleware(middleware, `${stalePath}@DropComponent`)).toBe('')
+    const keepBody = await invokeAngularMiddleware(middleware, `${stalePath}@KeepComponent`)
+    expect(keepBody).toContain('function KeepComponent_UpdateMetadata(KeepComponent')
+    expect(keepBody).toContain('keep-edited')
+  })
+
   it('triggers full reload when a multi-component .ts changes outside template/styles', async () => {
     const plugin = getAngularPlugin()
     const mockServer = await setupPluginWithServer(plugin)
@@ -2043,6 +2126,44 @@ describe('@ng/component endpoint resolves the styles per class', () => {
     expect(body).toContain('styles: []')
   })
 
+  // Vite hands `transform` forward-slash ids on every platform. The endpoint
+  // must look the file up by that same spelling, not a re-resolved one, or on
+  // Windows it serves nothing and never treats an empty style list as final.
+  it('serves the module for a forward-slash (Vite-normalized) component id', async () => {
+    const plugin = getAngularPlugin()
+    const mockServer = await setupPluginWithRealConfig(plugin)
+
+    const sibCssPath = normalizePath(join(appDir, 'ps-posix-sib.component.css'))
+    const posixPath = normalizePath(join(appDir, 'ps-posix.component.ts'))
+    writeFileSync(sibCssPath, '.PS_POSIX_SIB_MARKER { color: red; }')
+
+    const source = `
+      import { Component } from '@angular/core';
+      @Component({ selector: 'app-ps-posix', template: '<p>posix</p>', styles: [] })
+      export class PosixComponent {}
+      @Component({
+        selector: 'app-ps-posix-sib',
+        template: '<p>sib</p>',
+        styleUrls: ['./ps-posix-sib.component.css'],
+      })
+      export class PosixSiblingComponent {}
+    `
+    writeFileSync(posixPath, source)
+    await transformSource(plugin, source, posixPath)
+
+    writeFileSync(sibCssPath, '.PS_POSIX_SIB_MARKER { color: green; }')
+    const ctx = createMockHmrContext(sibCssPath, [{ id: sibCssPath }], mockServer)
+    await callHandleHotUpdate(plugin, ctx)
+    expectDispatched(mockServer, `${posixPath}@PosixComponent`)
+
+    const body = await invokeAngularMiddleware(
+      getMiddleware(mockServer),
+      `${posixPath}@PosixComponent`,
+    )
+    expect(body).toContain('function PosixComponent_UpdateMetadata(PosixComponent')
+    expect(body).toContain('styles: []')
+  })
+
   it('serves both entries of a `styleUrls` array mixing a constant with a literal', async () => {
     const plugin = getAngularPlugin()
     const mockServer = await setupPluginWithRealConfig(plugin)

napi/angular-compiler/test/ssr-hmr.test.ts

@@ -11,9 +11,15 @@
  * 2. `resolveId`/`load` hooks handle `@ng/component` as a safety net, returning
  *    an empty module so the module runner never crashes.
  */
+import { parseSync } from 'vite'
 import { describe, it, expect } from 'vitest'
 
-import { compileForHmrSync, transformAngularFile } from '../index.js'
+import {
+  compileForHmrSync,
+  generateHmrModule,
+  parseComponentId,
+  transformAngularFile,
+} from '../index.js'
 
 const COMPONENT_SOURCE = `
   import { Component } from '@angular/core';
@@ -105,3 +111,42 @@ describe('Component style minification', () => {
     expect(result.hmrModule).toContain('.container[_ngcontent-%COMP%]{color:red;background:0 0}')
   })
 })
+
+describe('compileForHmrSync with @ in the file path', () => {
+  it.each(['node_modules/@scope/pkg/src/a.ts', 'packages/@a/@b/x.ts'])(
+    'names the update function after the class for %s',
+    (filePath) => {
+      const result = compileForHmrSync('<div></div>', 'Foo', filePath, null, {})
+
+      expect(result.componentId).toBe(`${filePath}@Foo`)
+      expect(result.hmrModule).toContain(
+        'export default function Foo_UpdateMetadata(Foo, ɵɵnamespaces) {',
+      )
+      expect(parseSync('hmr.js', result.hmrModule).errors).toEqual([])
+    },
+  )
+
+  it.each([
+    ['node_modules/@scope/pkg/src/a.ts@Foo', 'node_modules/@scope/pkg/src/a.ts', 'Foo'],
+    ['packages/@a/@b/x.ts@Foo', 'packages/@a/@b/x.ts', 'Foo'],
+    ['Foo', 'Foo', ''],
+  ])('parseComponentId splits %s on the last @', (id, filePath, className) => {
+    expect(parseComponentId(id)).toEqual({ filePath, className })
+  })
+
+  it('generateHmrModule names the update function after the class', () => {
+    const hmrModule = generateHmrModule('node_modules/@scope/pkg/src/a.ts@Foo', 'null')
+
+    expect(hmrModule).toContain('export default function Foo_UpdateMetadata(Foo, ɵɵnamespaces) {')
+    expect(parseSync('hmr.js', hmrModule).errors).toEqual([])
+  })
+
+  it('transformAngularFile emits a parseable HMR initializer with the full id', async () => {
+    const filePath = 'node_modules/@scope/pkg/src/app.component.ts'
+    const result = await transformAngularFile(COMPONENT_SOURCE, filePath, { hmr: true })
+
+    expect(result.errors).toHaveLength(0)
+    expect(result.code).toContain(encodeURIComponent(`${filePath}@AppComponent`))
+    expect(parseSync('app.component.js', result.code).errors).toEqual([])
+  })
+})

napi/angular-compiler/vite-plugin/index.ts

@@ -602,7 +602,7 @@ export function angular(options: PluginOptions = {}): Plugin[] {
             }
 
             const decodedComponentId = decodeURIComponent(componentId)
-            const atIndex = decodedComponentId.indexOf('@')
+            const atIndex = decodedComponentId.lastIndexOf('@')
 
             // Validate component ID format: should be "filePath@ClassName"
             if (atIndex === -1) {
@@ -614,6 +614,9 @@ export function angular(options: PluginOptions = {}): Plugin[] {
 
             const fileId = decodedComponentId.slice(0, atIndex)
             const className = decodedComponentId.slice(atIndex + 1)
+            // `fileId` is the transform id verbatim, which is what the per-file
+            // maps are keyed by. `resolvedId` is for the filesystem only: on
+            // Windows it swaps Vite's forward slashes for backslashes.
             const resolvedId = resolve(process.cwd(), fileId)
 
             // Only return an HMR update module if `handleHotUpdate` queued
@@ -634,7 +637,7 @@ export function angular(options: PluginOptions = {}): Plugin[] {
             // around indefinitely because the transient-empty preservation
             // logic below assumes a future save will resolve it. Consume
             // and return empty.
-            if (!componentsByFile.get(resolvedId)?.has(className)) {
+            if (!componentsByFile.get(fileId)?.has(className)) {
               pendingHmrUpdates.delete(decodedComponentId)
               res.setHeader('Content-Type', 'text/javascript')
               res.setHeader('Cache-Control', 'no-cache')
@@ -791,7 +794,7 @@ export function angular(options: PluginOptions = {}): Plugin[] {
                 // read is still served on a mismatch — no worse than main,
                 // which scanned the same disk source.
                 const compiledFromThisSource = () => {
-                  const cachedStripped = componentMetadataCache.get(resolvedId)
+                  const cachedStripped = componentMetadataCache.get(fileId)
                   return (
                     cachedStripped !== undefined &&
                     cachedStripped === stripComponentMetadata(source)
@@ -1023,7 +1026,7 @@ export function angular(options: PluginOptions = {}): Plugin[] {
             )
             const classNamesInFile = new Set<string>()
             for (const componentId of templateUpdateKeys) {
-              const atIdx = componentId.indexOf('@')
+              const atIdx = componentId.lastIndexOf('@')
               if (atIdx === -1) continue
               classNamesInFile.add(componentId.slice(atIdx + 1))
             }