use the native node:punycode when available (#10882)

Author: vicb

.changeset/thirty-windows-own.md

@@ -0,0 +1,7 @@
+---
+"@cloudflare/unenv-preset": patch
+---
+
+Use the native `node:punycode` module when available.
+
+It is enabled when the `enable_nodejs_punycode_module` compatibility flag is set.

packages/unenv-preset/src/preset.ts

@@ -72,6 +72,7 @@ export function getCloudflarePreset({
 	const http2Overrides = getHttp2Overrides(compat);
 	const osOverrides = getOsOverrides(compat);
 	const fsOverrides = getFsOverrides(compat);
+	const punycodeOverrides = getPunycodeOverrides(compat);
 
 	// "dynamic" as they depend on the compatibility date and flags
 	const dynamicNativeModules = [
@@ -80,6 +81,7 @@ export function getCloudflarePreset({
 		...http2Overrides.nativeModules,
 		...osOverrides.nativeModules,
 		...fsOverrides.nativeModules,
+		...punycodeOverrides.nativeModules,
 	];
 
 	// "dynamic" as they depend on the compatibility date and flags
@@ -89,6 +91,7 @@ export function getCloudflarePreset({
 		...http2Overrides.hybridModules,
 		...osOverrides.hybridModules,
 		...fsOverrides.hybridModules,
+		...punycodeOverrides.hybridModules,
 	];
 
 	return {
@@ -305,3 +308,41 @@ function getFsOverrides({
 				hybridModules: [],
 			};
 }
+
+/**
+ * Returns the overrides for `node:punycode` (unenv or workerd)
+ *
+ * The native punycode implementation:
+ * - is experimental
+ * - can be enabled with the "enable_nodejs_punycode_module" flag
+ * - can be disabled with the "disable_nodejs_punycode_module" flag
+ */
+function getPunycodeOverrides({
+	// eslint-disable-next-line unused-imports/no-unused-vars
+	compatibilityDate,
+	compatibilityFlags,
+}: {
+	compatibilityDate: string;
+	compatibilityFlags: string[];
+}): { nativeModules: string[]; hybridModules: string[] } {
+	const disabledByFlag = compatibilityFlags.includes(
+		"disable_nodejs_punycode_module"
+	);
+
+	// TODO: add `enabledByDate` when a date is defined in workerd
+	const enabledByFlag =
+		compatibilityFlags.includes("enable_nodejs_punycode_module") &&
+		compatibilityFlags.includes("experimental");
+
+	const enabled = enabledByFlag && !disabledByFlag;
+
+	return enabled
+		? {
+				nativeModules: ["punycode"],
+				hybridModules: [],
+			}
+		: {
+				nativeModules: [],
+				hybridModules: [],
+			};
+}

packages/wrangler/e2e/unenv-preset/preset.test.ts

@@ -231,6 +231,28 @@ const testConfigs: TestConfig[] = [
 			},
 		},
 	],
+	// node:punycode
+	[
+		// TODO: add test for disabled by date (no date defined yet)
+		// TODO: add test for enabled by date (no date defined yet)
+		{
+			name: "punycode enabled by flag",
+			compatibilityDate: "2024-09-23",
+			compatibilityFlags: ["enable_nodejs_punycode_module", "experimental"],
+			expectRuntimeFlags: {
+				enable_nodejs_punycode_module: true,
+			},
+		},
+		// TODO: update the date past the default enable date (when defined)
+		{
+			name: "punycode disabled by flag",
+			compatibilityDate: "2024-09-23",
+			compatibilityFlags: ["disable_nodejs_punycode_module", "experimental"],
+			expectRuntimeFlags: {
+				enable_nodejs_punycode_module: false,
+			},
+		},
+	],
 ].flat() as TestConfig[];
 
 describe.each(testConfigs)(

packages/wrangler/e2e/unenv-preset/worker/index.ts

@@ -544,4 +544,21 @@ export const WorkerdTests: Record<string, () => void> = {
 		assert.equal(typeof gProcess.removeListener, "function");
 		assert.equal(typeof gProcess.setMaxListeners, "function");
 	},
+
+	async testPunycode() {
+		const punycode = await import("node:punycode");
+
+		assert.strictEqual(typeof punycode.decode, "function");
+		assert.strictEqual(typeof punycode.encode, "function");
+		assert.strictEqual(typeof punycode.toASCII, "function");
+		assert.strictEqual(typeof punycode.toUnicode, "function");
+		assert.strictEqual(
+			punycode.toASCII("Bücher@日本語.com"),
+			"Bü[email protected]"
+		);
+		assert.strictEqual(
+			punycode.toUnicode("Bü[email protected]"),
+			"Bücher@日本語.com"
+		);
+	},
 };