Add a working regression test

philipp-spiess · philipp-spiess · commit 23c044ac0334 · 2025-04-03T14:47:13.000+02:00
diff --git a/integrations/postcss/next.test.ts b/integrations/postcss/next.test.ts
@@ -356,94 +356,3 @@ test(
     })
   },
 )
-
-test(
-  'changes to CSS file should immediately reflect with HMR using `--turbopack`',
-  {
-    fs: {
-      'package.json': json`
-        {
-          "dependencies": {
-            "react": "^18",
-            "react-dom": "^18",
-            "next": "^15"
-          },
-          "devDependencies": {
-            "@tailwindcss/postcss": "workspace:^",
-            "tailwindcss": "workspace:^"
-          }
-        }
-      `,
-      '.gitignore': `
-        node_modules
-        .next/
-      `,
-      'postcss.config.mjs': js`
-        export default {
-          plugins: {
-            '@tailwindcss/postcss': {},
-          },
-        }
-      `,
-      'next.config.mjs': js`export default {}`,
-      'app/layout.js': js`
-        import './globals.css'
-
-        export default function RootLayout({ children }) {
-          return (
-            <html>
-              <body>{children}</body>
-            </html>
-          )
-        }
-      `,
-      'app/page.js': js`
-        export default function Page() {
-          return <div className="flex"></div>
-        }
-      `,
-      'app/globals.css': css`
-        @import 'tailwindcss/utilities' source(none);
-
-        body {
-          --value: 'before change';
-        }
-      `,
-    },
-  },
-  async ({ spawn, fs, expect }) => {
-    let process = await spawn(`pnpm next dev --turbopack`)
-
-    let url = ''
-    await process.onStdout((m) => {
-      let match = /Local:\s*(http.*)/.exec(m)
-      if (match) url = match[1]
-      return Boolean(url)
-    })
-
-    await process.onStdout((m) => m.includes('Ready in'))
-    await retryAssertion(async () => {
-      let css = await fetchStyles(url)
-      expect(css).toContain('before change')
-    })
-
-    await fs.write(
-      'app/globals.css',
-      css`
-        @import 'tailwindcss/utilities' source(none);
-
-        body {
-          --value: 'after change';
-        }
-      `,
-    )
-
-    await process.onStdout((m) => m.includes('Compiled / in'))
-
-    await retryAssertion(async () => {
-      let css = await fetchStyles(url)
-      expect(css).not.toContain('before change')
-      expect(css).toContain('after change')
-    })
-  },
-)
diff --git a/packages/@tailwindcss-postcss/src/index.test.ts b/packages/@tailwindcss-postcss/src/index.test.ts
@@ -1,5 +1,5 @@
 import dedent from 'dedent'
-import { mkdir, mkdtemp, unlink, writeFile } from 'node:fs/promises'
+import { mkdir, mkdtemp, readFile, rm, unlink, writeFile } from 'node:fs/promises'
 import { tmpdir } from 'node:os'
 import path from 'path'
 import postcss from 'postcss'
@@ -357,3 +357,64 @@ test('runs `Once` plugins in the right order', async () => {
     }"
   `)
 })
+
+describe('concurrent builds', () => {
+  let dir: string
+  beforeEach(async () => {
+    dir = await mkdtemp(path.join(tmpdir(), 'tw-postcss'))
+    await writeFile(path.join(dir, 'index.html'), `<div class="underline"></div>`)
+    await writeFile(
+      path.join(dir, 'index.css'),
+      css`
+        @import './dependency.css';
+      `,
+    )
+    await writeFile(
+      path.join(dir, 'dependency.css'),
+      css`
+        @tailwind utilities;
+      `,
+    )
+  })
+  afterEach(() => rm(dir, { recursive: true, force: true }))
+
+  test('the current working directory is used by default', async () => {
+    const spy = vi.spyOn(process, 'cwd')
+    spy.mockReturnValue(dir)
+
+    let from = path.join(dir, 'index.css')
+    let input = (await readFile(path.join(dir, 'index.css'))).toString()
+
+    let plugin = tailwindcss({ optimize: { minify: false } })
+
+    async function run(input: string): Promise<string> {
+      let ast = postcss.parse(input)
+      for (let runner of (plugin as any).plugins) {
+        if (runner.Once) {
+          await runner.Once(ast, { result: { opts: { from }, messages: [] } })
+        }
+      }
+      return ast.toString()
+    }
+
+    let result = await run(input)
+
+    expect(result).toContain('.underline')
+
+    await writeFile(
+      path.join(dir, 'dependency.css'),
+      css`
+        @tailwind utilities;
+        .red {
+          color: red;
+        }
+      `,
+    )
+
+    let promise1 = run(input)
+    let promise2 = run(input)
+
+    expect(await promise1).toContain('.red')
+    expect(await promise2).toContain('.red')
+  })
+})
diff --git a/packages/@tailwindcss-postcss/src/index.ts b/packages/@tailwindcss-postcss/src/index.ts
@@ -89,7 +89,8 @@ function tailwindcss(opts: PluginOptions = {}): AcceptedPlugin {
                 node.name === 'variant' ||
                 node.name === 'config' ||
                 node.name === 'plugin' ||
-                node.name === 'apply'
+                node.name === 'apply' ||
+                node.name === 'tailwind'
               ) {
                 canBail = false
                 return false
