feat: generate overrides.css on generate

packages/preset-umi/fixtures/overrides/less/index.less

@@ -0,0 +1,7 @@
+@import "foo/foo.less";
+
+@red: green;
+.a {
+  aaa: @red;
+  bbb: @primary-color;
+}

packages/preset-umi/fixtures/overrides/normal/foo/bar/hoo.css

@@ -0,0 +1,3 @@
+.hoo {
+  color: red;
+}

packages/preset-umi/package.json

@@ -51,7 +51,9 @@
     "enhanced-resolve": "5.9.3",
     "fast-glob": "3.2.12",
     "html-webpack-plugin": "5.5.0",
+    "less-plugin-resolve": "1.0.0",
     "path-to-regexp": "1.7.0",
+    "postcss": "^8.4.21",
     "postcss-prefix-selector": "1.16.0",
     "react": "18.1.0",
     "react-dom": "18.1.0",

packages/preset-umi/src/features/overrides/compileLess.manullytest.ts

@@ -0,0 +1,43 @@
+import assert from 'assert';
+import fs from 'fs';
+import { join } from 'path';
+import { compileLess } from './compileLess';
+
+const fixturesDir = join(__dirname, '../../../fixtures');
+
+// 在 jest 下跑会出错，所以只能手动跑来验证了
+// test('normal', async () => {
+(async () => {
+  const filePath = join(fixturesDir, 'overrides/less/index.less');
+  const modifyVars = {
+    'primary-color': '#1DA57A',
+  };
+  const alias = {
+    barbar: join(filePath, '../node_modules/bar'),
+  };
+  const result = await compileLess(
+    fs.readFileSync(filePath, 'utf-8'),
+    filePath,
+    modifyVars,
+    alias,
+  );
+  assert(
+    result.includes(
+      `
+.bar {
+  color: red;
+}
+.foo {
+  color: red;
+}
+.a {
+  aaa: green;
+  bbb: #1DA57A;
+}
+  `.trim(),
+    ),
+  );
+})().catch((e) => {
+  console.error(e);
+});
+// });

packages/preset-umi/src/features/overrides/compileLess.ts

@@ -0,0 +1,20 @@
+import less from '@umijs/bundler-utils/compiled/less';
+
+export async function compileLess(
+  lessContent: string,
+  filePath: string,
+  modifyVars: Record<string, string> = {},
+  alias: Record<string, string> = {},
+) {
+  const result = await less.render(lessContent, {
+    filename: filePath,
+    plugins: [
+      new (require('less-plugin-resolve') as any)({
+        aliases: alias,
+      }),
+    ],
+    javascriptEnabled: true,
+    modifyVars,
+  });
+  return result.css;
+}

packages/preset-umi/src/features/overrides/overrides.ts

@@ -1,50 +1,48 @@
-import { winPath } from '@umijs/utils';
-import { existsSync } from 'fs';
+import { existsSync, readFileSync } from 'fs';
 import { join } from 'path';
 import { expandCSSPaths } from '../../commands/dev/watch';
 import type { IApi } from '../../types';
+import { compileLess } from './compileLess';
+import { transform } from './transform';
 
 export function getOverridesCSS(absSrcPath: string) {
   return expandCSSPaths(join(absSrcPath, 'overrides')).find(existsSync);
 }
 
 export default (api: IApi) => {
-  api.modifyConfig((memo) => {
-    if (getOverridesCSS(api.paths.absSrcPath)) {
-      memo.extraPostCSSPlugins ??= [];
-      memo.extraPostCSSPlugins.push(
-        // prefix #root for overrides.{ext} style file, to make sure selector priority is higher than async chunk style
-        require('postcss-prefix-selector')({
-          // why not #root?
-          // antd will insert dom into body, prefix #root will not works for that
-          prefix: 'body',
-          transform(
-            _p: string,
-            selector: string,
-            prefixedSelector: string,
-            filePath: string,
-          ) {
-            const isOverridesFile =
-              winPath(api.appData.overridesCSS[0]) === winPath(filePath);
-
-            if (isOverridesFile) {
-              if (selector === 'html') {
-                // special :first-child to promote html selector priority
-                return `html:first-child`;
-              } else if (/^body([\s+~>[:]|$)/.test(selector)) {
-                // use html parent to promote body selector priority
-                return `html ${selector}`;
-              }
-
-              return prefixedSelector;
-            }
-
-            return selector;
+  let cachedContent: string | null = null;
+  api.onGenerateFiles(async () => {
+    if (api.appData.overridesCSS.length) {
+      const filePath = api.appData.overridesCSS[0];
+      let content = readFileSync(filePath, 'utf-8');
+      if (content === cachedContent) return;
+      const isLess = filePath.endsWith('.less');
+      if (isLess) {
+        content = await compileLess(
+          content,
+          filePath,
+          {
+            ...api.config.theme,
+            ...api.config.lessLoader?.modifyVars,
           },
-        }),
-      );
+          api.config.alias,
+        );
+      }
+      content = await transform(content, filePath);
+      api.writeTmpFile({
+        path: 'core/overrides.css',
+        content,
+        noPluginDir: true,
+      });
+      cachedContent = content;
     }
+  });
 
-    return memo;
+  api.addEntryImports(() => {
+    return [
+      api.appData.overridesCSS.length && {
+        source: '@@/core/overrides.css',
+      },
+    ].filter(Boolean);
   });
 };

packages/preset-umi/src/features/overrides/transform.test.ts

@@ -0,0 +1,79 @@
+import { winPath } from '@umijs/utils';
+import { join } from 'path';
+import { transform } from './transform';
+
+const fixturesDir = join(__dirname, '../../../fixtures');
+
+test('transform selector', async () => {
+  const result = await transform(
+    `
+html {}
+.a {}
+#b {}
+div {}
+@media (max-width: 100px) {
+  .b {}
+}
+  `,
+    '/foo/bar/hoo.css',
+  );
+  expect(result).toEqual(`
+html:first-child {}
+body .a {}
+body #b {}
+body div {}
+@media (max-width: 100px) {
+  body .b {}
+}
+  `);
+});
+
+test('transform import', async () => {
+  const filePath = join(fixturesDir, 'overrides/normal/foo/bar/hoo.css');
+  const result = await transform(
+    `
+@import "a";
+@import "~b";
+@import "./a.css";
+@import './a.css';
+@import "../a.css";
+@import "../not-exists.css";
+@import "a.css";
+@import "child/a.css";
+@import "child/not-exists.css";
+  `,
+    filePath,
+  );
+  expect(result.replace(new RegExp(`${winPath(fixturesDir)}`, 'g'), ''))
+    .toEqual(`
+@import "a";
+@import "~b";
+@import "/overrides/normal/foo/bar/a.css";
+@import "/overrides/normal/foo/bar/a.css";
+@import "/overrides/normal/foo/a.css";
+@import "../not-exists.css";
+@import "/overrides/normal/foo/bar/a.css";
+@import "/overrides/normal/foo/bar/child/a.css";
+@import "child/not-exists.css";
+  `);
+});
+
+test('transform import with url', async () => {
+  const filePath = join(fixturesDir, 'overrides/normal/foo/bar/hoo.css');
+  const result = await transform(
+    `
+@import url("a.css");
+@import url('a.css');
+@import url(a.css);
+@import url(not-exists.css);
+  `,
+    filePath,
+  );
+  expect(result.replace(new RegExp(`${winPath(fixturesDir)}`, 'g'), ''))
+    .toEqual(`
+@import "/overrides/normal/foo/bar/a.css";
+@import "/overrides/normal/foo/bar/a.css";
+@import "/overrides/normal/foo/bar/a.css";
+@import url(not-exists.css);
+  `);
+});

packages/preset-umi/src/features/overrides/transform.ts

@@ -0,0 +1,59 @@
+import { winPath } from '@umijs/utils';
+import fs from 'fs';
+import path from 'path';
+import type { AtRule } from 'postcss';
+
+export async function transform(cssContent: string, filePath: string) {
+  const importPlugin = {
+    postcssPlugin: 'importPlugin',
+    AtRule: {
+      import(atRule: AtRule) {
+        let origin = atRule.params;
+        // remove url() wrapper
+        origin = origin.replace(/^url\((.+)\)$/g, '$1');
+        // remove start ' or " and end ' or "
+        origin = origin.replace(/^'(.+)'$/g, '$1').replace(/^"(.+)"$/g, '$1');
+
+        // ~ 开头的肯定是从 node_modules 下查找
+        if (origin.startsWith('~')) return;
+        if (origin.startsWith('/')) return;
+
+        function getResolvedPath(origin: string) {
+          return winPath(path.resolve(path.dirname(filePath), origin));
+        }
+
+        // 已经包含 ./ 和 ../ 的场景，不需要额外处理
+        // CSS 会优先找相对路径，如果找不到，会再找 node_modules 下的
+        const resolvedPath = getResolvedPath(origin);
+        if (fs.existsSync(resolvedPath)) {
+          atRule.params = `"${resolvedPath}"`;
+        } else {
+          // Warn user if file not exists, but it should be existed
+          if (origin.startsWith('./') || origin.startsWith('../')) {
+            console.warn(`File does not exist: ${resolvedPath}`);
+          }
+        }
+      },
+    },
+  };
+  const selectorPlugin = require('postcss-prefix-selector')({
+    // why not #root?
+    // antd will insert dom into body, prefix #root will not work for that
+    prefix: 'body',
+    transform(_p: string, selector: string, prefixedSelector: string) {
+      if (selector === 'html') {
+        // special :first-child to promote html selector priority
+        return `html:first-child`;
+      } else if (/^body([\s+~>[:]|$)/.test(selector)) {
+        // use html parent to promote body selector priority
+        return `html ${selector}`;
+      }
+      return prefixedSelector;
+    },
+  });
+  const result = await require('postcss')([
+    selectorPlugin,
+    importPlugin,
+  ]).process(cssContent, {});
+  return result.css;
+}

packages/preset-umi/src/features/tmpFiles/tmpFiles.ts

@@ -305,12 +305,7 @@ declare module '*.txt' {
         imports: importsToStr(
           await api.applyPlugins({
             key: 'addEntryImports',
-            initialValue: [
-              // append overrides.{ext} style file
-              api.appData.overridesCSS.length && {
-                source: api.appData.overridesCSS[0],
-              },
-            ].filter(Boolean),
+            initialValue: [],
           }),
         ).join('\n'),
         basename: api.config.base,