From 1dbd86b73481520352bbc9bd24f365f052b3f67e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=89=E5=92=B2=E6=99=BA=E5=AD=90=20Kevin=20Deng?=
 <sxzz@sxzz.moe>
Date: Mon, 16 Oct 2023 20:47:47 +0800
Subject: [PATCH] feat: support es3 target (#965)

---
 src/index.ts              |  4 +--
 src/plugins/es5.ts        | 52 -------------------------------
 src/plugins/swc-target.ts | 65 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+), 54 deletions(-)
 delete mode 100644 src/plugins/es5.ts
 create mode 100644 src/plugins/swc-target.ts

diff --git a/src/index.ts b/src/index.ts
index 0eecc990..f6d4ce70 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -16,7 +16,7 @@ import { runEsbuild } from './esbuild'
 import { shebang } from './plugins/shebang'
 import { cjsSplitting } from './plugins/cjs-splitting'
 import { PluginContainer } from './plugin'
-import { es5 } from './plugins/es5'
+import { swcTarget } from './plugins/swc-target'
 import { sizeReporter } from './plugins/size-reporter'
 import { treeShakingPlugin } from './plugins/tree-shaking'
 import { copyPublicDir, isInPublicDir } from './lib/public-dir'
@@ -256,7 +256,7 @@ export async function build(_options: Options) {
                     }),
                     cjsSplitting(),
                     cjsInterop(),
-                    es5(),
+                    swcTarget(),
                     sizeReporter(),
                     terserPlugin({
                       minifyOptions: options.minify,
diff --git a/src/plugins/es5.ts b/src/plugins/es5.ts
deleted file mode 100644
index 99bd9d11..00000000
--- a/src/plugins/es5.ts
+++ /dev/null
@@ -1,52 +0,0 @@
-import { PrettyError } from '../errors'
-import { Plugin } from '../plugin'
-import { localRequire } from '../utils'
-
-export const es5 = (): Plugin => {
-  let enabled = false
-  return {
-    name: 'es5-target',
-
-    esbuildOptions(options) {
-      if (options.target === 'es5') {
-        options.target = 'es2020'
-        enabled = true
-      }
-    },
-
-    async renderChunk(code, info) {
-      if (!enabled || !/\.(cjs|js)$/.test(info.path)) {
-        return
-      }
-      const swc: typeof import('@swc/core') = localRequire('@swc/core')
-
-      if (!swc) {
-        throw new PrettyError(
-          '@swc/core is required for es5 target. Please install it with `npm install @swc/core -D`'
-        )
-      }
-
-      const result = await swc.transform(code, {
-        filename: info.path,
-        sourceMaps: this.options.sourcemap,
-        minify: Boolean(this.options.minify),
-        jsc: {
-          target: 'es5',
-          parser: {
-            syntax: 'ecmascript',
-          },
-          minify: this.options.minify === true ? {
-            compress: false,
-            mangle: {
-              reserved: this.options.globalName ? [this.options.globalName] : []
-            },
-          } : undefined,
-        },
-      })
-      return {
-        code: result.code,
-        map: result.map,
-      }
-    },
-  }
-}
diff --git a/src/plugins/swc-target.ts b/src/plugins/swc-target.ts
new file mode 100644
index 00000000..25aa6d5a
--- /dev/null
+++ b/src/plugins/swc-target.ts
@@ -0,0 +1,65 @@
+import { PrettyError } from '../errors'
+import { Plugin } from '../plugin'
+import { localRequire } from '../utils'
+
+const TARGETS = ['es5', 'es3'] as const
+
+export const swcTarget = (): Plugin => {
+  let enabled = false
+  let target: typeof TARGETS[number]
+
+  return {
+    name: 'swc-target',
+
+    esbuildOptions(options) {
+      if (
+        typeof options.target === 'string' &&
+        TARGETS.includes(options.target as any)
+      ) {
+        target = options.target as any
+        options.target = 'es2020'
+        enabled = true
+      }
+    },
+
+    async renderChunk(code, info) {
+      if (!enabled || !/\.(cjs|js)$/.test(info.path) || this.format !== 'cjs') {
+        return
+      }
+      const swc: typeof import('@swc/core') = localRequire('@swc/core')
+
+      if (!swc) {
+        throw new PrettyError(
+          `@swc/core is required for ${target} target. Please install it with \`npm install @swc/core -D\``
+        )
+      }
+
+      const result = await swc.transform(code, {
+        filename: info.path,
+        sourceMaps: this.options.sourcemap,
+        minify: Boolean(this.options.minify),
+        jsc: {
+          target,
+          parser: {
+            syntax: 'ecmascript',
+          },
+          minify:
+            this.options.minify === true
+              ? {
+                  compress: false,
+                  mangle: {
+                    reserved: this.options.globalName
+                      ? [this.options.globalName]
+                      : [],
+                  },
+                }
+              : undefined,
+        },
+      })
+      return {
+        code: result.code,
+        map: result.map,
+      }
+    },
+  }
+}