fix(shared): Preserve import.meta without requiring ES2020 target

.changeset/fuzzy-radios-tease.md

@@ -0,0 +1,5 @@
+---
+"@clerk/shared": minor
+---
+
+Fix compatibility with iOS 12 and older browsers while maintaining Vite support

packages/shared/tsup.config.ts

@@ -24,9 +24,8 @@ export default defineConfig(overrideOptions => {
     minify: false,
     sourcemap: true,
     dts: true,
-    target: 'es2020',
     external: ['react', 'react-dom'],
-    esbuildPlugins: [WebWorkerMinifyPlugin as any],
+    esbuildPlugins: [WebWorkerMinifyPlugin as any, PreserveImportMetaPlugin],
     define: {
       PACKAGE_NAME: `"${name}"`,
       PACKAGE_VERSION: `"${version}"`,
@@ -49,3 +48,28 @@ export const WebWorkerMinifyPlugin: Plugin = {
     });
   },
 };
+
+/**
+ * Preserves import.meta functionality in ESM builds while maintaining ES5 compatibility.
+ * We originally used target: 'es2020' to handle this but it broke support for older browsers (e.g. iOS 12).
+ */
+const PreserveImportMetaPlugin: Plugin = {
+  name: 'PreserveImportMetaPlugin',
+  setup(build) {
+    build.onEnd(result => {
+      if (!result.outputFiles) return;
+
+      result.outputFiles.forEach(file => {
+        if (!file.path.endsWith('.mjs')) return;
+
+        const contents = file.contents;
+        const text = new TextDecoder().decode(contents);
+
+        // Remove esbuild's var import_meta = {} transformation and restore original import.meta references
+        const modified = text.replace(/var\s+import_meta\s*=\s*{};/g, '').replace(/import_meta/g, 'import.meta');
+
+        file.contents = new TextEncoder().encode(modified);
+      });
+    });
+  },
+};