Upgrade: don't show error during upgrade when analyzing external URL import

CHANGELOG.md

@@ -20,6 +20,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Ensure `flex` is suggested ([#15014](https://github.com/tailwindlabs/tailwindcss/pull/15014))
 - _Upgrade (experimental)_: Resolve imports when specifying a CSS entry point on the command-line ([#15010](https://github.com/tailwindlabs/tailwindcss/pull/15010))
 - _Upgrade (experimental)_: Resolve nearest Tailwind config file when CSS file does not contain `@config` ([#15001](https://github.com/tailwindlabs/tailwindcss/pull/15001))
+- _Upgrade (experimental)_: Improve output when CSS imports can not be found ([#15038](https://github.com/tailwindlabs/tailwindcss/pull/15038))
+- _Upgrade (experimental)_: Ignore analyzing imports with external URLs (e.g.: `@import "https://fonts.google.com"`) ([#15040](https://github.com/tailwindlabs/tailwindcss/pull/15040))
+- _Upgrade (experimental)_: Ignore analyzing imports with `url(…)` (e.g.: `@import url("https://fonts.google.com")`) ([#15040](https://github.com/tailwindlabs/tailwindcss/pull/15040))
 
 ### Changed
 

packages/@tailwindcss-upgrade/src/codemods/migrate-import.test.ts

@@ -1,29 +1,22 @@
-import { __unstable__loadDesignSystem } from '@tailwindcss/node'
 import dedent from 'dedent'
 import postcss from 'postcss'
 import { expect, it } from 'vitest'
-import type { UserConfig } from '../../../tailwindcss/src/compat/config/types'
 import { migrateImport } from './migrate-import'
 
 const css = dedent
 
-async function migrate(input: string, userConfig: UserConfig = {}) {
+async function migrate(input: string) {
   return postcss()
-    .use(
-      migrateImport({
-        designSystem: await __unstable__loadDesignSystem(`@import 'tailwindcss';`, {
-          base: __dirname,
-        }),
-        userConfig,
-      }),
-    )
+    .use(migrateImport())
     .process(input, { from: expect.getState().testPath })
     .then((result) => result.css)
 }
 
 it('prints relative file imports as relative paths', async () => {
   expect(
     await migrate(css`
+      @import url('https://example.com');
+
       @import 'fixtures/test';
       @import 'fixtures/test.css';
       @import './fixtures/test.css';
@@ -62,7 +55,9 @@ it('prints relative file imports as relative paths', async () => {
       @import 'tailwindcss/theme';
     `),
   ).toMatchInlineSnapshot(`
-    "@import './fixtures/test.css';
+    "@import url('https://example.com');
+
+    @import './fixtures/test.css';
     @import './fixtures/test.css';
     @import './fixtures/test.css';
     @import './fixtures/test.css';

packages/@tailwindcss-upgrade/src/codemods/migrate-import.ts

@@ -12,27 +12,33 @@ export function migrateImport(): Plugin {
 
     let promises: Promise<void>[] = []
     root.walkAtRules('import', (rule) => {
-      let [firstParam, ...rest] = segment(rule.params, ' ')
-
-      let params = parseImportParams(ValueParser.parse(firstParam))
-
-      let isRelative = params.uri[0] === '.'
-      let hasCssExtension = params.uri.endsWith('.css')
-
-      if (isRelative && hasCssExtension) {
-        return
+      try {
+        let [firstParam, ...rest] = segment(rule.params, ' ')
+
+        let params = parseImportParams(ValueParser.parse(firstParam))
+
+        let isRelative = params.uri[0] === '.'
+        let hasCssExtension = params.uri.endsWith('.css')
+
+        if (isRelative && hasCssExtension) {
+          return
+        }
+
+        let fullPath = resolve(dirname(file), params.uri)
+        if (!hasCssExtension) fullPath += '.css'
+
+        promises.push(
+          fs.stat(fullPath).then(() => {
+            let ext = hasCssExtension ? '' : '.css'
+            let path = isRelative ? params.uri : `./${params.uri}`
+            rule.params = [`'${path}${ext}'`, ...rest].join(' ')
+          }),
+        )
+      } catch {
+        // When an error occurs while parsing the `@import` statement, we skip
+        // the import. This will happen in cases where you import an external
+        // URL.
       }
-
-      let fullPath = resolve(dirname(file), params.uri)
-      if (!hasCssExtension) fullPath += '.css'
-
-      promises.push(
-        fs.stat(fullPath).then(() => {
-          let ext = hasCssExtension ? '' : '.css'
-          let path = isRelative ? params.uri : `./${params.uri}`
-          rule.params = [`'${path}${ext}'`, ...rest].join(' ')
-        }),
-      )
     })
 
     await Promise.allSettled(promises)

packages/@tailwindcss-upgrade/src/migrate.ts

@@ -120,6 +120,13 @@ export async function analyze(stylesheets: Stylesheet[]) {
               resolvedPath = resolveCssId(id, basePath)
             }
           } catch (err) {
+            // Import is a URL, we don't want to process these, but also don't
+            // want to show an error message for them.
+            if (id.startsWith('http://') || id.startsWith('https://') || id.startsWith('//')) {
+              return
+            }
+
+            // Something went wrong, we can't resolve the import.
             error(
               `Failed to resolve import: ${highlight(id)} in ${highlight(relative(node.source?.input.file!, basePath))}. Skipping.`,
               { prefix: '↳ ' },