add various e2e and fixture tests for dotenv support

- `wrangler types`
- `wrangler pages dev`
- `wrangler dev`
- nodejs app using `process.env`

Author: petebacondarwin

fixtures/nodejs-hybrid-app/.env

@@ -0,0 +1 @@
+DEV_VAR_FROM_DOT_ENV="dev-var-from-dot-env"

fixtures/nodejs-hybrid-app/.gitignore

@@ -0,0 +1 @@
+!.env

fixtures/nodejs-hybrid-app/src/index.ts

@@ -22,6 +22,10 @@ export default {
 				return testGetRandomValues();
 			case "/test-process":
 				return testProcessBehavior();
+			case "/env":
+				return Response.json(env);
+			case "/process-env":
+				return Response.json(process.env);
 			case "/query":
 				return testPostgresLibrary(env, ctx);
 			case "/test-x509-certificate":

fixtures/nodejs-hybrid-app/tests/index.test.ts

@@ -88,4 +88,26 @@ describe("nodejs compat", () => {
 		const response = await fetch(`http://${ip}:${port}/test-http`);
 		await expect(response.text()).resolves.toBe("OK");
 	});
+
+	test("process.env contains vars", async ({ expect }) => {
+		const { ip, port } = wrangler;
+		const response = await fetch(`http://${ip}:${port}/process-env`);
+		await expect(response.json()).resolves.toEqual(
+			expect.objectContaining({
+				DB_HOSTNAME: "hh-pgsql-public.ebi.ac.uk",
+				DEV_VAR_FROM_DOT_ENV: "dev-var-from-dot-env",
+			})
+		);
+	});
+
+	test("env contains vars", async ({ expect }) => {
+		const { ip, port } = wrangler;
+		const response = await fetch(`http://${ip}:${port}/env`);
+		await expect(response.json()).resolves.toEqual(
+			expect.objectContaining({
+				DB_HOSTNAME: "hh-pgsql-public.ebi.ac.uk",
+				DEV_VAR_FROM_DOT_ENV: "dev-var-from-dot-env",
+			})
+		);
+	});
 });

fixtures/nodejs-hybrid-app/wrangler.jsonc

@@ -1,8 +1,9 @@
 {
 	"name": "nodejs-hybrid-app",
 	"main": "src/index.ts",
-	// Setting compat date to 2024/09/23 means we don't need to use `nodejs_compat_v2`
-	"compatibility_date": "2024-09-23",
+	// Setting compat date after 2024/09/23 means we don't need to use `nodejs_compat_v2`
+	// Setting compat date after 2025/04/01 means we don't need to use `nodejs_compat_populate_process_env`
+	"compatibility_date": "2025-07-01",
 	"compatibility_flags": ["nodejs_compat"],
 	/*
     These DB connection values are to a public database containing information about

fixtures/pages-workerjs-app/.env

@@ -0,0 +1 @@
+FOO=bar

fixtures/pages-workerjs-app/.gitignore

@@ -0,0 +1 @@
+!.env

fixtures/pages-workerjs-app/package.json

@@ -4,7 +4,7 @@
 	"sideEffects": false,
 	"scripts": {
 		"check:type": "tsc",
-		"dev": "wrangler pages dev ./workerjs-test --port 8792",
+		"dev": "wrangler pages dev ./workerjs-test --port 8792 --compatibility-date=2025-07-15",
 		"test:ci": "vitest run",
 		"test:watch": "vitest",
 		"type:tests": "tsc -p ./tests/tsconfig.json"

fixtures/pages-workerjs-app/tests/index.test.ts

@@ -35,7 +35,12 @@ describe("Pages _worker.js", () => {
 		const { ip, port, stop } = await runWranglerPagesDev(
 			resolve(__dirname, ".."),
 			"./workerjs-test",
-			["--no-bundle=false", "--port=0", "--inspector-port=0"]
+			[
+				"--no-bundle=false",
+				"--port=0",
+				"--inspector-port=0",
+				"--compatibility-date=2025-07-15",
+			]
 		);
 		try {
 			await expect(
@@ -52,7 +57,12 @@ describe("Pages _worker.js", () => {
 		const { ip, port, stop } = await runWranglerPagesDev(
 			resolve(__dirname, ".."),
 			"./workerjs-test",
-			["--bundle", "--port=0", "--inspector-port=0"]
+			[
+				"--bundle",
+				"--port=0",
+				"--inspector-port=0",
+				"--compatibility-date=2025-07-15",
+			]
 		);
 		try {
 			await expect(
@@ -71,6 +81,7 @@ describe("Pages _worker.js", () => {
 			await runWranglerPagesDev(resolve(__dirname, ".."), "./workerjs-test", [
 				"--port=0",
 				"--inspector-port=0",
+				"--compatibility-date=2025-07-15",
 			]);
 		try {
 			clearOutput();
@@ -139,6 +150,22 @@ describe("Pages _worker.js", () => {
 		}
 	});
 
+	// Serendipitously, this .env reading also works for `wrangler pages dev`.
+	it("should read local dev vars from the .env file", async ({ expect }) => {
+		const { ip, port, stop } = await runWranglerPagesDev(
+			resolve(__dirname, ".."),
+			"./workerjs-test",
+			["--port=0", "--inspector-port=0", "--compatibility-date=2025-07-15"]
+		);
+		try {
+			const response = await fetch(`http://${ip}:${port}/env`);
+			const env = (await response.json()) as { FOO: string };
+			expect(env.FOO).toBe("bar");
+		} finally {
+			await stop();
+		}
+	});
+
 	async function tryRename(
 		basePath: string,
 		from: string,

fixtures/pages-workerjs-app/workerjs-test/_worker.js

@@ -1,7 +1,11 @@
 import text from "./other-script";
 
 export default {
-	async fetch() {
-		return new Response(text);
+	async fetch(request, env) {
+		if (request.url.endsWith("/env")) {
+			return Response.json(env);
+		} else {
+			return new Response(text);
+		}
 	},
 };