Handle css-loader file resolving change

packages/next/build/webpack/config/blocks/css/loaders/file-resolve.ts

@@ -0,0 +1,6 @@
+export function cssFileResolve(url: string, _resourcePath: string) {
+  if (url.startsWith('/')) {
+    return false
+  }
+  return true
+}

packages/next/build/webpack/config/blocks/css/loaders/global.ts

@@ -2,6 +2,7 @@ import postcss from 'postcss'
 import webpack from 'webpack'
 import { ConfigurationContext } from '../../../utils'
 import { getClientStyleLoader } from './client'
+import { cssFileResolve } from './file-resolve'
 
 export function getGlobalCssLoader(
   ctx: ConfigurationContext,
@@ -29,6 +30,9 @@ export function getGlobalCssLoader(
       sourceMap: true,
       // Next.js controls CSS Modules eligibility:
       modules: false,
+      url: cssFileResolve,
+      import: (url: string, _: any, resourcePath: string) =>
+        cssFileResolve(url, resourcePath),
     },
   })
 

packages/next/build/webpack/config/blocks/css/loaders/modules.ts

@@ -2,6 +2,7 @@ import postcss from 'postcss'
 import webpack from 'webpack'
 import { ConfigurationContext } from '../../../utils'
 import { getClientStyleLoader } from './client'
+import { cssFileResolve } from './file-resolve'
 import { getCssModuleLocalIdent } from './getCssModuleLocalIdent'
 
 export function getCssModuleLoader(
@@ -30,6 +31,9 @@ export function getCssModuleLoader(
       sourceMap: true,
       // Use CJS mode for backwards compatibility:
       esModule: false,
+      url: cssFileResolve,
+      import: (url: string, _: any, resourcePath: string) =>
+        cssFileResolve(url, resourcePath),
       modules: {
         // Do not transform class names (CJS mode backwards compatibility):
         exportLocalsConvention: 'asIs',

test/integration/css-fixtures/unresolved-css-url/global.css

@@ -0,0 +1,31 @@
+p {
+  background-image: url('/vercel.svg');
+}
+
+p:nth-child(1) {
+  background-image: url(/vercel.svg);
+}
+
+/* p:nth-child(2) {
+  background-image: url('./vercel.svg');
+}
+
+p:nth-child(3) {
+  background-image: url(./vercel.svg);
+} */
+
+p:nth-child(4) {
+  background-image: url('./public/vercel.svg');
+}
+
+p:nth-child(5) {
+  background-image: url(./public/vercel.svg);
+}
+
+div {
+  background-image: url('https://vercel.com/vercel.svg');
+}
+
+div:nth-child(1) {
+  background-image: url('https://vercel.com/vercel.svg');
+}

test/integration/css-fixtures/unresolved-css-url/global.scss

@@ -0,0 +1,31 @@
+.p {
+  background-image: url('/vercel.svg');
+}
+
+.p:nth-child(1) {
+  background-image: url(/vercel.svg);
+}
+
+// .p:nth-child(2) {
+//   background-image: url('./vercel.svg');
+// }
+
+// .p:nth-child(3) {
+//   background-image: url(./vercel.svg);
+// }
+
+p:nth-child(4) {
+  background-image: url('./public/vercel.svg');
+}
+
+p:nth-child(5) {
+  background-image: url(./public/vercel.svg);
+}
+
+.div {
+  background-image: url('https://vercel.com/vercel.svg');
+}
+
+.div:nth-child(1) {
+  background-image: url('https://vercel.com/vercel.svg');
+}

test/integration/css-fixtures/unresolved-css-url/pages/_app.js

@@ -0,0 +1,6 @@
+import '../global.css'
+import '../global.scss'
+
+export default function MyApp({ Component, pageProps }) {
+  return <Component {...pageProps} />
+}

test/integration/css-fixtures/unresolved-css-url/pages/another.js

@@ -0,0 +1,5 @@
+import styles from './another.module.scss'
+
+export default function Page() {
+  return <p className={styles.first}>Hello from index</p>
+}

test/integration/css-fixtures/unresolved-css-url/pages/another.module.scss

@@ -0,0 +1,31 @@
+.first {
+  background-image: url('/vercel.svg');
+}
+
+.first:nth-child(1) {
+  background-image: url(/vercel.svg);
+}
+
+// .first:nth-child(2) {
+//   background-image: url('./vercel.svg');
+// }
+
+// .first:nth-child(3) {
+//   background-image: url(./vercel.svg);
+// }
+
+.first:nth-child(4) {
+  background-image: url('../public/vercel.svg');
+}
+
+.first:nth-child(5) {
+  background-image: url(../public/vercel.svg);
+}
+
+.another {
+  background-image: url('https://vercel.com/vercel.svg');
+}
+
+.another:nth-child(1) {
+  background-image: url('https://vercel.com/vercel.svg');
+}

test/integration/css-fixtures/unresolved-css-url/pages/index.js

@@ -0,0 +1,5 @@
+import styles from './index.module.css'
+
+export default function Page() {
+  return <p className={styles.first}>Hello from index</p>
+}

test/integration/css-fixtures/unresolved-css-url/pages/index.module.css

@@ -0,0 +1,31 @@
+.first {
+  background-image: url('/vercel.svg');
+}
+
+.first:nth-child(1) {
+  background-image: url(/vercel.svg);
+}
+
+/* .first:nth-child(2) {
+  background-image: url('./vercel.svg');
+}
+
+.first:nth-child(3) {
+  background-image: url(./vercel.svg);
+} */
+
+.first:nth-child(4) {
+  background-image: url('../public/vercel.svg');
+}
+
+.first:nth-child(5) {
+  background-image: url(../public/vercel.svg);
+}
+
+.another {
+  background-image: url('https://vercel.com/vercel.svg');
+}
+
+.another:nth-child(1) {
+  background-image: url('https://vercel.com/vercel.svg');
+}

test/integration/css/test/index.test.js

@@ -1532,4 +1532,37 @@ describe('CSS Support', () => {
       tests()
     })
   })
+
+  describe('should handle unresolved files gracefully', () => {
+    const workDir = join(fixturesDir, 'unresolved-css-url')
+
+    it('should build correctly', async () => {
+      await remove(join(workDir, '.next'))
+      const { code } = await nextBuild(workDir)
+      expect(code).toBe(0)
+    })
+
+    it('should have correct file references in CSS output', async () => {
+      const cssFiles = await readdir(join(workDir, '.next/static/css'))
+
+      for (const file of cssFiles) {
+        if (file.endsWith('.css.map')) continue
+
+        const content = await readFile(
+          join(workDir, '.next/static/css', file),
+          'utf8'
+        )
+        console.log(file, content)
+
+        // if it is the combined global CSS file there are double the expected
+        // results
+        const howMany = content.includes('p{') ? 4 : 2
+
+        expect(content.match(/\(\/vercel\.svg/g).length).toBe(howMany)
+        // expect(content.match(/\(vercel\.svg/g).length).toBe(howMany)
+        expect(content.match(/\(\/_next\/static\/media/g).length).toBe(2)
+        expect(content.match(/\(https:\/\//g).length).toBe(howMany)
+      }
+    })
+  })
 })