add support for native node:os (#10208)

Co-authored-by: Yagiz Nizipli <yagiz@nizipli.com>

Author: vicb

.changeset/cold-hands-reply.md

@@ -0,0 +1,5 @@
+---
+"@cloudflare/unenv-preset": minor
+---
+
+add support for native `node:os`

packages/unenv-preset/package.json

@@ -51,7 +51,7 @@
 	},
 	"peerDependencies": {
 		"unenv": "2.0.0-rc.19",
-		"workerd": "^1.20250730.0"
+		"workerd": "^1.20250802.0"
 	},
 	"peerDependenciesMeta": {
 		"workerd": {

packages/unenv-preset/src/preset.ts

@@ -71,16 +71,23 @@ export function getCloudflarePreset({
 		compatibilityFlags,
 	});
 
+	const osOverrides = getOsOverrides({
+		compatibilityDate,
+		compatibilityFlags,
+	});
+
 	// "dynamic" as they depend on the compatibility date and flags
 	const dynamicNativeModules = [
 		...nativeModules,
 		...httpOverrides.nativeModules,
+		...osOverrides.nativeModules,
 	];
 
 	// "dynamic" as they depend on the compatibility date and flags
 	const dynamicHybridModules = [
 		...hybridModules,
 		...httpOverrides.hybridModules,
+		...osOverrides.hybridModules,
 	];
 
 	return {
@@ -138,6 +145,7 @@ export function getCloudflarePreset({
  *
  * The native http server APIS implementation:
  * - can be enabled with the "enable_nodejs_http_server_modules" flag
+ * - can be disabled with the "disable_nodejs_http_server_modules" flag
  */
 function getHttpOverrides({
 	compatibilityDate,
@@ -149,31 +157,31 @@ function getHttpOverrides({
 	const httpDisabledByFlag = compatibilityFlags.includes(
 		"disable_nodejs_http_modules"
 	);
-	const httpEnabledByFlags = compatibilityFlags.includes(
+	const httpEnabledByFlag = compatibilityFlags.includes(
 		"enable_nodejs_http_modules"
 	);
 	const httpEnabledByDate = compatibilityDate >= "2025-08-15";
 
 	const httpEnabled =
-		(httpEnabledByFlags || httpEnabledByDate) && !httpDisabledByFlag;
+		(httpEnabledByFlag || httpEnabledByDate) && !httpDisabledByFlag;
 
 	if (!httpEnabled) {
 		// use the unenv polyfill
 		return { nativeModules: [], hybridModules: [] };
 	}
 
-	const httpServerEnabledByFlags = compatibilityFlags.includes(
-		"enable_nodejs_http_server_modules"
-	);
+	const httpServerEnabledByFlag =
+		compatibilityFlags.includes("enable_nodejs_http_server_modules") &&
+		compatibilityFlags.includes("experimental");
 
-	const httpServerDisabledByFlags = compatibilityFlags.includes(
+	const httpServerDisabledByFlag = compatibilityFlags.includes(
 		"disable_nodejs_http_server_modules"
 	);
 
 	// Note that `httpServerEnabled` requires `httpEnabled`
 	// TODO: add `httpServerEnabledByDate` when a default date is set
 	const httpServerEnabled =
-		httpServerEnabledByFlags && !httpServerDisabledByFlags;
+		httpServerEnabledByFlag && !httpServerDisabledByFlag;
 
 	// Override unenv base aliases with native and hybrid modules
 	// `node:https` is fully implemented by workerd if both flags are enabled
@@ -189,3 +197,42 @@ function getHttpOverrides({
 		hybridModules: httpServerEnabled ? ["http"] : ["http", "https"],
 	};
 }
+
+/**
+ * Returns the overrides for `node:os` (unenv or workerd)
+ *
+ * The native http implementation:
+ * - can be enabled with the "enable_nodejs_os_module" flag
+ * - can be disabled with the "disable_nodejs_os_module" flag
+ */
+function getOsOverrides({
+	// 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_os_module"
+	);
+
+	const enabledByFlag =
+		compatibilityFlags.includes("enable_nodejs_os_module") &&
+		compatibilityFlags.includes("experimental");
+
+	// TODO: add `enabledByDate` when a default date is set
+	const enabled = enabledByFlag && !disabledByFlag;
+
+	// The native os module implements all the APIs.
+	// It can then be used as a native module.
+	return enabled
+		? {
+				nativeModules: ["os"],
+				hybridModules: [],
+			}
+		: {
+				nativeModules: [],
+				hybridModules: [],
+			};
+}

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

@@ -15,8 +15,9 @@ type TestConfig = {
 	compatibilityFlags?: string[];
 	// Assert runtime compatibility flag values
 	expectRuntimeFlags?: {
-		// Whether the http modules are enabled
-		enable_nodejs_http_modules: boolean;
+		enable_nodejs_http_modules?: boolean;
+		enable_nodejs_http_server_modules?: boolean;
+		enable_nodejs_os_module?: boolean;
 	};
 };
 
@@ -95,6 +96,35 @@ const testConfigs: TestConfig[] = [
 			},
 		},
 	],
+	// node:os
+	[
+		{
+			name: "os disabled by date",
+			compatibilityDate: "2025-07-26",
+			compatibilityFlags: ["experimental"],
+			expectRuntimeFlags: {
+				enable_nodejs_os_module: false,
+			},
+		},
+		// TODO: add a config when os is enabled by default (date no set yet)
+		{
+			name: "os enabled by flag",
+			compatibilityDate: "2025-07-26",
+			compatibilityFlags: ["enable_nodejs_os_module", "experimental"],
+			expectRuntimeFlags: {
+				enable_nodejs_os_module: true,
+			},
+		},
+		// TODO: change the date pass the default enabled date (date not set yet)
+		{
+			name: "os disabled by flag",
+			compatibilityDate: "2025-07-26",
+			compatibilityFlags: ["disable_nodejs_os_module", "experimental"],
+			expectRuntimeFlags: {
+				enable_nodejs_os_module: false,
+			},
+		},
+	],
 ].flat();
 
 describe.each(testConfigs)(

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

@@ -243,7 +243,7 @@ export const WorkerdTests: Record<string, () => void> = {
 	},
 
 	async testHttp() {
-		const http = await import("http");
+		const http = await import("node:http");
 
 		const useNativeHttp = getRuntimeFlagValue("enable_nodejs_http_modules");
 
@@ -270,7 +270,7 @@ export const WorkerdTests: Record<string, () => void> = {
 	},
 
 	async testHttps() {
-		const https = await import("https");
+		const https = await import("node:https");
 
 		assert.strictEqual(typeof https.Agent, "function");
 		assert.strictEqual(typeof https.get, "function");
@@ -279,7 +279,7 @@ export const WorkerdTests: Record<string, () => void> = {
 	},
 
 	async testHttpServer() {
-		const http = await import("http");
+		const http = await import("node:http");
 
 		const useNativeHttp = getRuntimeFlagValue(
 			"enable_nodejs_http_server_modules"
@@ -303,7 +303,7 @@ export const WorkerdTests: Record<string, () => void> = {
 	},
 
 	async testHttpsServer() {
-		const https = await import("https");
+		const https = await import("node:https");
 
 		const useNativeHttp = getRuntimeFlagValue(
 			"enable_nodejs_http_server_modules"
@@ -325,4 +325,12 @@ export const WorkerdTests: Record<string, () => void> = {
 			assert.throws(() => new https.Server(), /not implemented/);
 		}
 	},
+
+	async testOs() {
+		const os = await import("node:os");
+
+		assert.strictEqual(typeof os.arch(), "string");
+		assert.strictEqual(typeof os.freemem(), "number");
+		assert.strictEqual(typeof os.availableParallelism(), "number");
+	},
 };