fix: now cjs shims should only be injected when it's actually used

assets/cjs_shims.js

@@ -1,7 +1,12 @@
 // Shim globals in cjs bundle
+// There's a weird bug that esbuild will always inject importMetaUrl
+// if we export it as `const importMetaUrl = ... __filename ...`
+// But using a function will not cause this issue
 
-export const importMetaUrlShim =
+const getImportMetaUrl = () =>
   typeof document === 'undefined'
     ? new URL('file:' + __filename).href
     : (document.currentScript && document.currentScript.src) ||
       new URL('main.js', document.baseURI).href
+
+export const importMetaUrl = /* @__PURE__ */ getImportMetaUrl()

assets/esm_shims.js

@@ -2,7 +2,8 @@
 import { fileURLToPath } from 'url'
 import path from 'path'
 
-const __filename = fileURLToPath(import.meta.url)
-const __dirname = path.dirname(__filename)
+const getFilename = () => fileURLToPath(import.meta.url)
+const getDirname = () => path.dirname(getFilename())
 
-export { __dirname, __filename }
+export const __dirname = /* @__PURE__ */ getDirname()
+export const __filename = /* @__PURE__ */ getFilename()

src/esbuild/index.ts

@@ -158,7 +158,7 @@ export async function runEsbuild(
       define: {
         ...(format === 'cjs' && injectShims
           ? {
-              'import.meta.url': 'importMetaUrlShim',
+              'import.meta.url': 'importMetaUrl',
             }
           : {}),
         ...options.define,

test/snapshots/index.test.ts.md

@@ -393,10 +393,11 @@ Generated by [AVA](https://avajs.dev).
     });␊
     ␊
     // ../../../assets/cjs_shims.js␊
-    var importMetaUrlShim = typeof document === "undefined" ? new URL("file:" + __filename).href : document.currentScript && document.currentScript.src || new URL("main.js", document.baseURI).href;␊
+    var getImportMetaUrl = () => typeof document === "undefined" ? new URL("file:" + __filename).href : document.currentScript && document.currentScript.src || new URL("main.js", document.baseURI).href;␊
+    var importMetaUrl = /* @__PURE__ */ getImportMetaUrl();␊
     ␊
     // input.ts␊
-    var input_default = importMetaUrlShim;␊
+    var input_default = importMetaUrl;␊
     // Annotate the CommonJS export names for ESM import in node:␊
     0 && (module.exports = {});␊
     `
@@ -408,8 +409,10 @@ Generated by [AVA](https://avajs.dev).
     `// ../../../assets/esm_shims.js␊
     import { fileURLToPath } from "url";␊
     import path from "path";␊
-    var __filename = fileURLToPath(import.meta.url);␊
-    var __dirname = path.dirname(__filename);␊
+    var getFilename = () => fileURLToPath(import.meta.url);␊
+    var getDirname = () => path.dirname(getFilename());␊
+    var __dirname = /* @__PURE__ */ getDirname();␊
+    var __filename = /* @__PURE__ */ getFilename();␊
     ␊
     // input.ts␊
     var a = __dirname;␊