fix: should set output charset for swc-loader

e2e/cases/output/charset/index.test.ts

@@ -1,7 +1,42 @@
-import { build } from '@e2e/helper';
+import { build, dev, rspackOnlyTest } from '@e2e/helper';
 import { expect, test } from '@playwright/test';
 
-test('should allow to set output.charset to ascii', async ({ page }) => {
+rspackOnlyTest(
+  'should allow to set output.charset to ascii in development mode',
+  async ({ page }) => {
+    const rsbuild = await dev({
+      cwd: __dirname,
+      page,
+      rsbuildConfig: {
+        dev: {
+          writeToDisk: true,
+        },
+        output: {
+          charset: 'ascii',
+        },
+      },
+    });
+
+    expect(await page.evaluate('window.a')).toBe('你好 world!');
+
+    const files = await rsbuild.getDistFiles();
+
+    const [, content] = Object.entries(files).find(
+      ([name]) => name.endsWith('.js') && name.includes('static/js/index'),
+    )!;
+
+    // in Rspack is: \\u4f60\\u597D world!
+    expect(
+      content.toLocaleLowerCase().includes('\\u4f60\\u597d world!'),
+    ).toBeTruthy();
+
+    await rsbuild.close();
+  },
+);
+
+test('should allow to set output.charset to ascii in production mode', async ({
+  page,
+}) => {
   const rsbuild = await build({
     cwd: __dirname,
     page,
@@ -28,7 +63,9 @@ test('should allow to set output.charset to ascii', async ({ page }) => {
   await rsbuild.close();
 });
 
-test('should allow to set output.charset to utf8', async ({ page }) => {
+test('should allow to set output.charset to utf8 in production mode', async ({
+  page,
+}) => {
   const rsbuild = await build({
     cwd: __dirname,
     rsbuildConfig: {

packages/core/src/plugins/swc.ts

@@ -62,10 +62,15 @@ function applyScriptCondition({
   }
 }
 
-function getDefaultSwcConfig(
-  browserslist: string[],
-  cacheRoot: string,
-): SwcLoaderOptions {
+function getDefaultSwcConfig({
+  browserslist,
+  cacheRoot,
+  config,
+}: {
+  browserslist: string[];
+  cacheRoot: string;
+  config: NormalizedEnvironmentConfig;
+}): SwcLoaderOptions {
   return {
     jsc: {
       externalHelpers: true,
@@ -81,6 +86,9 @@ function getDefaultSwcConfig(
          */
         keepImportAttributes: true,
       },
+      output: {
+        charset: config.output.charset,
+      },
     },
     isModule: 'unknown',
     env: {
@@ -137,7 +145,11 @@ export const pluginSwc = (): RsbuildPlugin => ({
           return;
         }
 
-        const swcConfig = getDefaultSwcConfig(browserslist, cacheRoot);
+        const swcConfig = getDefaultSwcConfig({
+          browserslist,
+          cacheRoot,
+          config,
+        });
 
         applyTransformImport(swcConfig, config.source.transformImport);
         applySwcDecoratorConfig(swcConfig, config);

packages/core/tests/__snapshots__/builder.test.ts.snap

@@ -147,6 +147,9 @@ exports[`should use Rspack as the default bundler > apply Rspack correctly 1`] =
                   "keepImportAttributes": true,
                 },
                 "externalHelpers": true,
+                "output": {
+                  "charset": "utf8",
+                },
                 "parser": {
                   "decorators": true,
                   "syntax": "typescript",
@@ -196,6 +199,9 @@ exports[`should use Rspack as the default bundler > apply Rspack correctly 1`] =
                   "keepImportAttributes": true,
                 },
                 "externalHelpers": true,
+                "output": {
+                  "charset": "utf8",
+                },
                 "parser": {
                   "decorators": true,
                   "syntax": "typescript",

packages/core/tests/__snapshots__/default.test.ts.snap

@@ -147,6 +147,9 @@ exports[`applyDefaultPlugins > should apply default plugins correctly 1`] = `
                   "keepImportAttributes": true,
                 },
                 "externalHelpers": true,
+                "output": {
+                  "charset": "utf8",
+                },
                 "parser": {
                   "decorators": true,
                   "syntax": "typescript",
@@ -196,6 +199,9 @@ exports[`applyDefaultPlugins > should apply default plugins correctly 1`] = `
                   "keepImportAttributes": true,
                 },
                 "externalHelpers": true,
+                "output": {
+                  "charset": "utf8",
+                },
                 "parser": {
                   "decorators": true,
                   "syntax": "typescript",
@@ -625,6 +631,9 @@ exports[`applyDefaultPlugins > should apply default plugins correctly when prod
                   "keepImportAttributes": true,
                 },
                 "externalHelpers": true,
+                "output": {
+                  "charset": "utf8",
+                },
                 "parser": {
                   "decorators": true,
                   "syntax": "typescript",
@@ -674,6 +683,9 @@ exports[`applyDefaultPlugins > should apply default plugins correctly when prod
                   "keepImportAttributes": true,
                 },
                 "externalHelpers": true,
+                "output": {
+                  "charset": "utf8",
+                },
                 "parser": {
                   "decorators": true,
                   "syntax": "typescript",
@@ -1103,6 +1115,9 @@ exports[`applyDefaultPlugins > should apply default plugins correctly when targe
                   "keepImportAttributes": true,
                 },
                 "externalHelpers": true,
+                "output": {
+                  "charset": "utf8",
+                },
                 "parser": {
                   "decorators": true,
                   "syntax": "typescript",
@@ -1148,6 +1163,9 @@ exports[`applyDefaultPlugins > should apply default plugins correctly when targe
                   "keepImportAttributes": true,
                 },
                 "externalHelpers": true,
+                "output": {
+                  "charset": "utf8",
+                },
                 "parser": {
                   "decorators": true,
                   "syntax": "typescript",
@@ -1539,6 +1557,9 @@ exports[`tools.rspack > should match snapshot 1`] = `
                   "keepImportAttributes": true,
                 },
                 "externalHelpers": true,
+                "output": {
+                  "charset": "utf8",
+                },
                 "parser": {
                   "decorators": true,
                   "syntax": "typescript",
@@ -1588,6 +1609,9 @@ exports[`tools.rspack > should match snapshot 1`] = `
                   "keepImportAttributes": true,
                 },
                 "externalHelpers": true,
+                "output": {
+                  "charset": "utf8",
+                },
                 "parser": {
                   "decorators": true,
                   "syntax": "typescript",

packages/core/tests/__snapshots__/environments.test.ts.snap

@@ -1442,6 +1442,9 @@ exports[`environment config > tools.rspack / bundlerChain can be configured in e
                     "keepImportAttributes": true,
                   },
                   "externalHelpers": true,
+                  "output": {
+                    "charset": "utf8",
+                  },
                   "parser": {
                     "decorators": true,
                     "syntax": "typescript",
@@ -1491,6 +1494,9 @@ exports[`environment config > tools.rspack / bundlerChain can be configured in e
                     "keepImportAttributes": true,
                   },
                   "externalHelpers": true,
+                  "output": {
+                    "charset": "utf8",
+                  },
                   "parser": {
                     "decorators": true,
                     "syntax": "typescript",
@@ -1832,6 +1838,9 @@ exports[`environment config > tools.rspack / bundlerChain can be configured in e
                     "keepImportAttributes": true,
                   },
                   "externalHelpers": true,
+                  "output": {
+                    "charset": "utf8",
+                  },
                   "parser": {
                     "decorators": true,
                     "syntax": "typescript",
@@ -1877,6 +1886,9 @@ exports[`environment config > tools.rspack / bundlerChain can be configured in e
                     "keepImportAttributes": true,
                   },
                   "externalHelpers": true,
+                  "output": {
+                    "charset": "utf8",
+                  },
                   "parser": {
                     "decorators": true,
                     "syntax": "typescript",