add node builtins only for workers under nodejs compat

Author: dario-piotrowicz

packages/vite-plugin-cloudflare/src/cloudflare-environment.ts

@@ -1,4 +1,3 @@
-import { builtinModules } from 'node:module';
 import * as path from 'node:path';
 import * as vite from 'vite';
 import { INIT_PATH, invariant, UNKNOWN_HOST } from './shared';
@@ -135,11 +134,9 @@ export function createCloudflareEnvironmentOptions(
 				// Note: in order for ssr pre-bundling to take effect we need to ask vite to treat all
 				//       dependencies as not external
 				noExternal: true,
-				builtins: [
-					// TODO: we should assume that the node modules are built in only if the nodejs_compat flag is set
-					...builtinModules.concat(builtinModules.map((m) => `node:${m}`)),
-					...cloudflareBuiltInModules,
-				],
+				// We want to use `workerd` package exports if available (e.g. for postgres).
+				conditions: ['workerd', 'module', 'browser', 'development|production'],
+				builtins: [...cloudflareBuiltInModules],
 			},
 			dev: {
 				createEnvironment(name, config) {
@@ -164,10 +161,7 @@ export function createCloudflareEnvironmentOptions(
 			optimizeDeps: {
 				// Note: ssr pre-bundling is opt-in, and we need to enabled it by setting noDiscovery to false
 				noDiscovery: false,
-				exclude: [
-					...cloudflareBuiltInModules,
-					...builtinModules.concat(builtinModules.map((m) => `node:${m}`)),
-				],
+				exclude: [...cloudflareBuiltInModules],
 				esbuildOptions: {
 					resolveExtensions: [
 						'.mjs',

packages/vite-plugin-cloudflare/src/index.ts

@@ -1,3 +1,4 @@
+import { builtinModules } from 'node:module';
 import { createMiddleware } from '@hattip/adapter-node';
 import { Miniflare } from 'miniflare';
 import * as vite from 'vite';
@@ -9,6 +10,7 @@ import { getMiniflareOptions } from './miniflare-options';
 import {
 	getNodeCompatAliases,
 	injectGlobalCode,
+	isNodeCompat,
 	resolveNodeAliases,
 } from './node-js-compat';
 import { normalizePluginConfig } from './plugin-config';
@@ -66,6 +68,9 @@ export function cloudflare<T extends Record<string, WorkerOptions>>(
 				pluginConfig,
 				resolvedConfig,
 			);
+			Object.keys(pluginConfig.workers).forEach((name) =>
+				addNodeBuiltinsIfNeeded(resolvedConfig, name, normalizedPluginConfig),
+			);
 		},
 		resolveId(source) {
 			const worker = normalizedPluginConfig.workers[this.environment.name];
@@ -147,3 +152,38 @@ export function cloudflare<T extends Record<string, WorkerOptions>>(
 		},
 	};
 }
+
+/**
+ * Adds the a worker resolved configuration the necessary node builtin config options is the worker is using under nodejs compat
+ *
+ * @param resolvedConfig the vite resolved config (that will be side-effectfully updated)
+ * @param name the name of the worker
+ * @param normalizedPluginConfig the normalized/resolved plugin config
+ */
+function addNodeBuiltinsIfNeeded(
+	resolvedConfig: vite.ResolvedConfig,
+	name: string,
+	normalizedPluginConfig: NormalizedPluginConfig,
+) {
+	invariant(
+		resolvedConfig.environments[name] && normalizedPluginConfig.workers[name],
+		`environment configs for worker "${name}" not found`,
+	);
+
+	const nodeCompat = isNodeCompat(
+		normalizedPluginConfig.workers[name].workerOptions,
+	);
+
+	const nodeCompatModules = nodeCompat
+		? [...builtinModules.concat(builtinModules.map((m) => `node:${m}`))]
+		: [];
+
+	resolvedConfig.environments[name].resolve.builtins = [
+		...resolvedConfig.environments[name].resolve.builtins,
+		...nodeCompatModules,
+	];
+	resolvedConfig.environments[name].optimizeDeps.exclude = [
+		...(resolvedConfig.environments[name].optimizeDeps.exclude ?? []),
+		...nodeCompatModules,
+	];
+}