From 18900fdd39d65da77846c01297e497995e234ece Mon Sep 17 00:00:00 2001
From: Ferdinand Thiessen <opensource@fthiessen.de>
Date: Tue, 10 Oct 2023 16:52:34 +0200
Subject: [PATCH] refactor(css): make `getEmptyChunkReplacer` for unit test
 (#14528)

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>
Co-authored-by: bluwy <bjornlu.dev@gmail.com>
---
 .../src/node/__tests__/plugins/css.spec.ts    | 55 +++++++++++++++++++
 packages/vite/src/node/plugins/css.ts         | 50 ++++++++++++-----
 2 files changed, 91 insertions(+), 14 deletions(-)

diff --git a/packages/vite/src/node/__tests__/plugins/css.spec.ts b/packages/vite/src/node/__tests__/plugins/css.spec.ts
index cccdda396f8df6..d206e5b73e90d1 100644
--- a/packages/vite/src/node/__tests__/plugins/css.spec.ts
+++ b/packages/vite/src/node/__tests__/plugins/css.spec.ts
@@ -7,6 +7,7 @@ import {
   convertTargets,
   cssPlugin,
   cssUrlRE,
+  getEmptyChunkReplacer,
   hoistAtRules,
 } from '../../plugins/css'
 
@@ -258,3 +259,57 @@ describe('convertTargets', () => {
     })
   })
 })
+
+describe('getEmptyChunkReplacer', () => {
+  test('replaces import call', () => {
+    const code = `\
+import "some-module";
+import "pure_css_chunk.js";
+import "other-module";`
+
+    const replacer = getEmptyChunkReplacer(['pure_css_chunk.js'], 'es')
+    const replaced = replacer(code)
+    expect(replaced.length).toBe(code.length)
+    expect(replaced).toMatchInlineSnapshot(`
+      "import \\"some-module\\";
+      /* empty css              */import \\"other-module\\";"
+    `)
+  })
+
+  test('replaces import call without new lines', () => {
+    const code = `import "some-module";import "pure_css_chunk.js";import "other-module";`
+
+    const replacer = getEmptyChunkReplacer(['pure_css_chunk.js'], 'es')
+    const replaced = replacer(code)
+    expect(replaced.length).toBe(code.length)
+    expect(replaced).toMatchInlineSnapshot(
+      '"import \\"some-module\\";/* empty css             */import \\"other-module\\";"',
+    )
+  })
+
+  test('replaces require call', () => {
+    const code = `\
+require("some-module");
+require("pure_css_chunk.js");
+require("other-module");`
+
+    const replacer = getEmptyChunkReplacer(['pure_css_chunk.js'], 'cjs')
+    const replaced = replacer(code)
+    expect(replaced.length).toBe(code.length)
+    expect(replaced).toMatchInlineSnapshot(`
+      "require(\\"some-module\\");
+      /* empty css                */require(\\"other-module\\");"
+    `)
+  })
+
+  test('replaces require call in minified code without new lines', () => {
+    const code = `require("some-module");require("pure_css_chunk.js");require("other-module");`
+
+    const replacer = getEmptyChunkReplacer(['pure_css_chunk.js'], 'cjs')
+    const replaced = replacer(code)
+    expect(replaced.length).toBe(code.length)
+    expect(replaced).toMatchInlineSnapshot(
+      '"require(\\"some-module\\");/* empty css               */require(\\"other-module\\");"',
+    )
+  })
+})
diff --git a/packages/vite/src/node/plugins/css.ts b/packages/vite/src/node/plugins/css.ts
index 85ba5eea8e5b89..133370be37036d 100644
--- a/packages/vite/src/node/plugins/css.ts
+++ b/packages/vite/src/node/plugins/css.ts
@@ -6,6 +6,7 @@ import glob from 'fast-glob'
 import postcssrc from 'postcss-load-config'
 import type {
   ExistingRawSourceMap,
+  ModuleFormat,
   OutputChunk,
   RenderedChunk,
   RollupError,
@@ -735,16 +736,11 @@ export function cssPostPlugin(config: ResolvedConfig): Plugin {
           (pureCssChunk) => prelimaryNameToChunkMap[pureCssChunk.fileName],
         )
 
-        const emptyChunkFiles = pureCssChunkNames
-          .map((file) => path.basename(file))
-          .join('|')
-          .replace(/\./g, '\\.')
-        const emptyChunkRE = new RegExp(
-          opts.format === 'es'
-            ? `\\bimport\\s*["'][^"']*(?:${emptyChunkFiles})["'];\n?`
-            : `\\brequire\\(\\s*["'][^"']*(?:${emptyChunkFiles})["']\\);\n?`,
-          'g',
+        const replaceEmptyChunk = getEmptyChunkReplacer(
+          pureCssChunkNames,
+          opts.format,
         )
+
         for (const file in bundle) {
           const chunk = bundle[file]
           if (chunk.type === 'chunk') {
@@ -766,13 +762,10 @@ export function cssPostPlugin(config: ResolvedConfig): Plugin {
               }
               return true
             })
-            chunk.code = chunk.code.replace(
-              emptyChunkRE,
-              // remove css import while preserving source map location
-              (m) => `/* empty css ${''.padEnd(m.length - 15)}*/`,
-            )
+            chunk.code = replaceEmptyChunk(chunk.code)
           }
         }
+
         const removedPureCssFiles = removedPureCssFilesCache.get(config)!
         pureCssChunkNames.forEach((fileName) => {
           removedPureCssFiles.set(fileName, bundle[fileName] as RenderedChunk)
@@ -818,6 +811,35 @@ export function cssPostPlugin(config: ResolvedConfig): Plugin {
   }
 }
 
+/**
+ * Create a replacer function that takes code and replaces given pure CSS chunk imports
+ * @param pureCssChunkNames The chunks that only contain pure CSS and should be replaced
+ * @param outputFormat The module output format to decide whether to replace `import` or `require`
+ */
+export function getEmptyChunkReplacer(
+  pureCssChunkNames: string[],
+  outputFormat: ModuleFormat,
+): (code: string) => string {
+  const emptyChunkFiles = pureCssChunkNames
+    .map((file) => path.basename(file))
+    .join('|')
+    .replace(/\./g, '\\.')
+
+  const emptyChunkRE = new RegExp(
+    outputFormat === 'es'
+      ? `\\bimport\\s*["'][^"']*(?:${emptyChunkFiles})["'];\n?`
+      : `\\brequire\\(\\s*["'][^"']*(?:${emptyChunkFiles})["']\\);\n?`,
+    'g',
+  )
+
+  return (code: string) =>
+    code.replace(
+      emptyChunkRE,
+      // remove css import while preserving source map location
+      (m) => `/* empty css ${''.padEnd(m.length - 15)}*/`,
+    )
+}
+
 interface CSSAtImportResolvers {
   css: ResolveFn
   sass: ResolveFn