Fix browser bundled string_decoder (#3693)

* Fix #3660

* doc fix

docs/bundler/index.md

@@ -307,7 +307,7 @@ Depending on the target, Bun will apply different module resolution rules and op
 ---
 
 - `browser`
-- _Default._ For generating bundles that are intended for execution by a browser. Prioritizes the `"browser"` export condition when resolving imports. An error will be thrown if any Node.js or Bun built-ins are imported or used, e.g. `node:fs` or `Bun.serve`.
+- _Default._ For generating bundles that are intended for execution by a browser. Prioritizes the `"browser"` export condition when resolving imports. Importing any built-in modules, like `node:events` or `node:path` will work, but calling some functions, like `fs.readFile` will not work.
 
 ---
 
@@ -1272,7 +1272,17 @@ interface BuildArtifact extends Blob {
   sourcemap?: BuildArtifact;
 }
 
-type Loader = "js" | "jsx" | "ts" | "tsx" | "json" | "toml" | "file" | "napi" | "wasm" | "text";
+type Loader =
+  | "js"
+  | "jsx"
+  | "ts"
+  | "tsx"
+  | "json"
+  | "toml"
+  | "file"
+  | "napi"
+  | "wasm"
+  | "text";
 
 interface BuildOutput {
   outputs: BuildArtifact[];

src/node-fallbacks/string_decoder.js

@@ -1,2 +1 @@
-export * from "string_decoder";
-export * as default from "string_decoder";
+export { StringDecoder, StringDecoder as default } from "string_decoder";

test/bundler/bundler_regressions.test.ts

@@ -180,4 +180,20 @@ describe("bundler", () => {
       file: "/entry.js",
     },
   });
+
+  // https://github.com/oven-sh/bun/issues/3660
+  itBundled("regression/StringDecoder#3660", {
+    files: {
+      "/entry.js": `
+        import { StringDecoder } from 'string_decoder'
+
+        const decoder = new StringDecoder('utf8')
+        const buf = Buffer.from([0xe4, 0xbd, 0xa0, 0xe5, 0xa5, 0xbd])
+        const str = decoder.write(buf)
+
+        console.log(str)
+      `,
+    },
+    run: { stdout: "你好" },
+  });
 });