From 68fac09dbd600dcdf184de4f8e39169d6188b6e0 Mon Sep 17 00:00:00 2001
From: Pete Bacon Darwin <pete@bacondarwin.com>
Date: Tue, 18 Jun 2024 12:32:03 +0100
Subject: [PATCH] chore: change vitest config to be ESM (for sure) to avoid
 warnings (#6055)

Without this we often see:

```
 The CJS build of Vite's Node API is deprecated. See https://vitejs.dev/guide/troubleshooting.html#vite-cjs-node-api-deprecated for more details.
```
---
 CONTRIBUTING.md                               |  2 +-
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 fixtures/local-mode-tests/tsconfig.json       |  2 +-
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../test/fetch-integration-self.test.ts       |  2 +-
 .../test/scheduled-integration-self.test.ts   |  2 +-
 .../vitest-pool-workers-examples/d1/README.md |  2 +-
 .../d1/test/env.d.ts                          |  2 +-
 .../hyperdrive/README.md                      |  2 +-
 .../hyperdrive/wrangler.toml                  |  2 +-
 .../misc/test/defines.test.ts                 |  2 +-
 .../multiple-workers/test/env.d.ts            |  2 +-
 .../test/integration-self.test.ts             |  2 +-
 .../queue-consumer-integration-self.test.ts   |  2 +-
 .../queues/test/queue-producer-unit.test.ts   |  2 +-
 .../queues/wrangler.toml                      |  2 +-
 .../vitest.workspace.ts                       |  2 +-
 .../{vitest.config.ts => vitest.config.mts}   |  0
 lint-turbo.mjs                                |  5 +++-
 .../{vitest.config.ts => vitest.config.mts}   |  0
 packages/create-cloudflare/package.json       |  6 ++---
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 packages/vitest-pool-workers/.eslintrc.js     |  2 +-
 .../src/worker/fetch-mock.ts                  |  2 +-
 .../vitest-pool-workers/test/chunking.test.ts |  2 +-
 .../vitest-pool-workers/test/console.test.ts  |  4 +--
 .../test/isolation.test.ts                    |  8 +++---
 .../test/snapshots.test.ts                    |  6 ++---
 .../test/validation.test.ts                   | 26 +++++++++----------
 .../vitest-pool-workers/test/watch.test.ts    |  4 +--
 packages/vitest-pool-workers/tsconfig.json    |  2 +-
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 .../{vitest.config.ts => vitest.config.mts}   |  0
 packages/wrangler/package.json                |  2 +-
 .../{vitest.config.ts => vitest.config.mts}   |  0
 tools/{vitest.config.ts => vitest.config.mts} |  0
 vitest.workspace.ts                           |  6 ++---
 74 files changed, 54 insertions(+), 51 deletions(-)
 rename fixtures/additional-modules/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/ai-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/dev-env/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/durable-objects-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/entrypoints-rpc-tests/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/external-durable-objects-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/external-service-bindings-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/get-bindings-proxy/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/get-platform-proxy/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/import-wasm-example/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/interactive-dev-tests/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/local-mode-tests/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/no-bundle-import/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/node-app-pages/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/nodejs-hybrid-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-d1-shim/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-dev-proxy-with-script/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-functions-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-functions-wasm-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-functions-with-config-file-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-functions-with-routes-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-plugin-mounted-on-root-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-proxy-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-simple-assets/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-workerjs-and-functions-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-workerjs-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-workerjs-directory/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-workerjs-wasm-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-workerjs-with-config-file-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-workerjs-with-routes-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/pages-ws-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/ratelimit-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/remix-pages-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/service-bindings-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/type-generation/{vitest.config.ts => vitest.config.mts} (100%)
 rename fixtures/worker-app/{vitest.config.ts => vitest.config.mts} (100%)
 rename packages/cli/{vitest.config.ts => vitest.config.mts} (100%)
 rename packages/create-cloudflare/templates/hello-world/ts/{vitest.config.ts => vitest.config.mts} (100%)
 rename packages/create-cloudflare/{vitest.config.ts => vitest.config.mts} (100%)
 rename packages/edge-preview-authenticated-proxy/{vitest.config.ts => vitest.config.mts} (100%)
 rename packages/pages-shared/{vitest.config.ts => vitest.config.mts} (100%)
 rename packages/vitest-pool-workers/{vitest.config.ts => vitest.config.mts} (100%)
 rename packages/workers.new/{vitest.config.ts => vitest.config.mts} (100%)
 rename packages/wrangler/e2e/{vitest.config.ts => vitest.config.mts} (100%)
 rename packages/wrangler/{vitest.config.ts => vitest.config.mts} (100%)
 rename tools/{vitest.config.ts => vitest.config.mts} (100%)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index c07d3c5ead2a..6c573398dbea 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -211,7 +211,7 @@ As a reviewer, it's important to be thoughtful about the proposed changes and co
 
 Every PR should include tests for the functionality that's being added. Most changes will be to [Wrangler](packages/wrangler/src/__tests__) (using Vitest), [Miniflare](packages/miniflare/test) (using Ava), or [C3](packages/create-cloudflare/src/__tests__) (using Vitest), and should include unit tests within the testing harness of those packages.
 
-If your PR includes functionality that's difficult to unit test, you can add a fixture test by creating a new package in the `fixtures/` folder. This allows for adding a test that requires a specific filesystem or worker setup (for instance, `fixtures/no-bundle-import` tests the interaction of Wrangler with a specific set of JS, WASM, text, and binary modules on the filesystem). When adding a fixture test, include a `vitest.config.ts` file within the new package, which will ensure it's run as part of the `workers-sdk` CI. You should merge your own configuration with the default config from the root of the repo.
+If your PR includes functionality that's difficult to unit test, you can add a fixture test by creating a new package in the `fixtures/` folder. This allows for adding a test that requires a specific filesystem or worker setup (for instance, `fixtures/no-bundle-import` tests the interaction of Wrangler with a specific set of JS, WASM, text, and binary modules on the filesystem). When adding a fixture test, include a `vitest.config.mts` file within the new package, which will ensure it's run as part of the `workers-sdk` CI. You should merge your own configuration with the default config from the root of the repo.
 
 A good default example is the following:
 
diff --git a/fixtures/additional-modules/vitest.config.ts b/fixtures/additional-modules/vitest.config.mts
similarity index 100%
rename from fixtures/additional-modules/vitest.config.ts
rename to fixtures/additional-modules/vitest.config.mts
diff --git a/fixtures/ai-app/vitest.config.ts b/fixtures/ai-app/vitest.config.mts
similarity index 100%
rename from fixtures/ai-app/vitest.config.ts
rename to fixtures/ai-app/vitest.config.mts
diff --git a/fixtures/dev-env/vitest.config.ts b/fixtures/dev-env/vitest.config.mts
similarity index 100%
rename from fixtures/dev-env/vitest.config.ts
rename to fixtures/dev-env/vitest.config.mts
diff --git a/fixtures/durable-objects-app/vitest.config.ts b/fixtures/durable-objects-app/vitest.config.mts
similarity index 100%
rename from fixtures/durable-objects-app/vitest.config.ts
rename to fixtures/durable-objects-app/vitest.config.mts
diff --git a/fixtures/entrypoints-rpc-tests/vitest.config.ts b/fixtures/entrypoints-rpc-tests/vitest.config.mts
similarity index 100%
rename from fixtures/entrypoints-rpc-tests/vitest.config.ts
rename to fixtures/entrypoints-rpc-tests/vitest.config.mts
diff --git a/fixtures/external-durable-objects-app/vitest.config.ts b/fixtures/external-durable-objects-app/vitest.config.mts
similarity index 100%
rename from fixtures/external-durable-objects-app/vitest.config.ts
rename to fixtures/external-durable-objects-app/vitest.config.mts
diff --git a/fixtures/external-service-bindings-app/vitest.config.ts b/fixtures/external-service-bindings-app/vitest.config.mts
similarity index 100%
rename from fixtures/external-service-bindings-app/vitest.config.ts
rename to fixtures/external-service-bindings-app/vitest.config.mts
diff --git a/fixtures/get-bindings-proxy/vitest.config.ts b/fixtures/get-bindings-proxy/vitest.config.mts
similarity index 100%
rename from fixtures/get-bindings-proxy/vitest.config.ts
rename to fixtures/get-bindings-proxy/vitest.config.mts
diff --git a/fixtures/get-platform-proxy/vitest.config.ts b/fixtures/get-platform-proxy/vitest.config.mts
similarity index 100%
rename from fixtures/get-platform-proxy/vitest.config.ts
rename to fixtures/get-platform-proxy/vitest.config.mts
diff --git a/fixtures/import-wasm-example/vitest.config.ts b/fixtures/import-wasm-example/vitest.config.mts
similarity index 100%
rename from fixtures/import-wasm-example/vitest.config.ts
rename to fixtures/import-wasm-example/vitest.config.mts
diff --git a/fixtures/interactive-dev-tests/vitest.config.ts b/fixtures/interactive-dev-tests/vitest.config.mts
similarity index 100%
rename from fixtures/interactive-dev-tests/vitest.config.ts
rename to fixtures/interactive-dev-tests/vitest.config.mts
diff --git a/fixtures/local-mode-tests/tsconfig.json b/fixtures/local-mode-tests/tsconfig.json
index 448c16f49bc9..e69cb8db6a92 100644
--- a/fixtures/local-mode-tests/tsconfig.json
+++ b/fixtures/local-mode-tests/tsconfig.json
@@ -9,7 +9,7 @@
 		"target": "esnext",
 		"strict": true,
 		"noEmit": true,
-		"types": ["@cloudflare/workers-types"],
+		"types": ["@cloudflare/workers-types", "node"],
 		"lib": ["esnext"],
 		"skipLibCheck": true
 	},
diff --git a/fixtures/local-mode-tests/vitest.config.ts b/fixtures/local-mode-tests/vitest.config.mts
similarity index 100%
rename from fixtures/local-mode-tests/vitest.config.ts
rename to fixtures/local-mode-tests/vitest.config.mts
diff --git a/fixtures/no-bundle-import/vitest.config.ts b/fixtures/no-bundle-import/vitest.config.mts
similarity index 100%
rename from fixtures/no-bundle-import/vitest.config.ts
rename to fixtures/no-bundle-import/vitest.config.mts
diff --git a/fixtures/node-app-pages/vitest.config.ts b/fixtures/node-app-pages/vitest.config.mts
similarity index 100%
rename from fixtures/node-app-pages/vitest.config.ts
rename to fixtures/node-app-pages/vitest.config.mts
diff --git a/fixtures/nodejs-hybrid-app/vitest.config.ts b/fixtures/nodejs-hybrid-app/vitest.config.mts
similarity index 100%
rename from fixtures/nodejs-hybrid-app/vitest.config.ts
rename to fixtures/nodejs-hybrid-app/vitest.config.mts
diff --git a/fixtures/pages-d1-shim/vitest.config.ts b/fixtures/pages-d1-shim/vitest.config.mts
similarity index 100%
rename from fixtures/pages-d1-shim/vitest.config.ts
rename to fixtures/pages-d1-shim/vitest.config.mts
diff --git a/fixtures/pages-dev-proxy-with-script/vitest.config.ts b/fixtures/pages-dev-proxy-with-script/vitest.config.mts
similarity index 100%
rename from fixtures/pages-dev-proxy-with-script/vitest.config.ts
rename to fixtures/pages-dev-proxy-with-script/vitest.config.mts
diff --git a/fixtures/pages-functions-app/vitest.config.ts b/fixtures/pages-functions-app/vitest.config.mts
similarity index 100%
rename from fixtures/pages-functions-app/vitest.config.ts
rename to fixtures/pages-functions-app/vitest.config.mts
diff --git a/fixtures/pages-functions-wasm-app/vitest.config.ts b/fixtures/pages-functions-wasm-app/vitest.config.mts
similarity index 100%
rename from fixtures/pages-functions-wasm-app/vitest.config.ts
rename to fixtures/pages-functions-wasm-app/vitest.config.mts
diff --git a/fixtures/pages-functions-with-config-file-app/vitest.config.ts b/fixtures/pages-functions-with-config-file-app/vitest.config.mts
similarity index 100%
rename from fixtures/pages-functions-with-config-file-app/vitest.config.ts
rename to fixtures/pages-functions-with-config-file-app/vitest.config.mts
diff --git a/fixtures/pages-functions-with-routes-app/vitest.config.ts b/fixtures/pages-functions-with-routes-app/vitest.config.mts
similarity index 100%
rename from fixtures/pages-functions-with-routes-app/vitest.config.ts
rename to fixtures/pages-functions-with-routes-app/vitest.config.mts
diff --git a/fixtures/pages-plugin-mounted-on-root-app/vitest.config.ts b/fixtures/pages-plugin-mounted-on-root-app/vitest.config.mts
similarity index 100%
rename from fixtures/pages-plugin-mounted-on-root-app/vitest.config.ts
rename to fixtures/pages-plugin-mounted-on-root-app/vitest.config.mts
diff --git a/fixtures/pages-proxy-app/vitest.config.ts b/fixtures/pages-proxy-app/vitest.config.mts
similarity index 100%
rename from fixtures/pages-proxy-app/vitest.config.ts
rename to fixtures/pages-proxy-app/vitest.config.mts
diff --git a/fixtures/pages-simple-assets/vitest.config.ts b/fixtures/pages-simple-assets/vitest.config.mts
similarity index 100%
rename from fixtures/pages-simple-assets/vitest.config.ts
rename to fixtures/pages-simple-assets/vitest.config.mts
diff --git a/fixtures/pages-workerjs-and-functions-app/vitest.config.ts b/fixtures/pages-workerjs-and-functions-app/vitest.config.mts
similarity index 100%
rename from fixtures/pages-workerjs-and-functions-app/vitest.config.ts
rename to fixtures/pages-workerjs-and-functions-app/vitest.config.mts
diff --git a/fixtures/pages-workerjs-app/vitest.config.ts b/fixtures/pages-workerjs-app/vitest.config.mts
similarity index 100%
rename from fixtures/pages-workerjs-app/vitest.config.ts
rename to fixtures/pages-workerjs-app/vitest.config.mts
diff --git a/fixtures/pages-workerjs-directory/vitest.config.ts b/fixtures/pages-workerjs-directory/vitest.config.mts
similarity index 100%
rename from fixtures/pages-workerjs-directory/vitest.config.ts
rename to fixtures/pages-workerjs-directory/vitest.config.mts
diff --git a/fixtures/pages-workerjs-wasm-app/vitest.config.ts b/fixtures/pages-workerjs-wasm-app/vitest.config.mts
similarity index 100%
rename from fixtures/pages-workerjs-wasm-app/vitest.config.ts
rename to fixtures/pages-workerjs-wasm-app/vitest.config.mts
diff --git a/fixtures/pages-workerjs-with-config-file-app/vitest.config.ts b/fixtures/pages-workerjs-with-config-file-app/vitest.config.mts
similarity index 100%
rename from fixtures/pages-workerjs-with-config-file-app/vitest.config.ts
rename to fixtures/pages-workerjs-with-config-file-app/vitest.config.mts
diff --git a/fixtures/pages-workerjs-with-routes-app/vitest.config.ts b/fixtures/pages-workerjs-with-routes-app/vitest.config.mts
similarity index 100%
rename from fixtures/pages-workerjs-with-routes-app/vitest.config.ts
rename to fixtures/pages-workerjs-with-routes-app/vitest.config.mts
diff --git a/fixtures/pages-ws-app/vitest.config.ts b/fixtures/pages-ws-app/vitest.config.mts
similarity index 100%
rename from fixtures/pages-ws-app/vitest.config.ts
rename to fixtures/pages-ws-app/vitest.config.mts
diff --git a/fixtures/ratelimit-app/vitest.config.ts b/fixtures/ratelimit-app/vitest.config.mts
similarity index 100%
rename from fixtures/ratelimit-app/vitest.config.ts
rename to fixtures/ratelimit-app/vitest.config.mts
diff --git a/fixtures/remix-pages-app/vitest.config.ts b/fixtures/remix-pages-app/vitest.config.mts
similarity index 100%
rename from fixtures/remix-pages-app/vitest.config.ts
rename to fixtures/remix-pages-app/vitest.config.mts
diff --git a/fixtures/service-bindings-app/vitest.config.ts b/fixtures/service-bindings-app/vitest.config.mts
similarity index 100%
rename from fixtures/service-bindings-app/vitest.config.ts
rename to fixtures/service-bindings-app/vitest.config.mts
diff --git a/fixtures/type-generation/vitest.config.ts b/fixtures/type-generation/vitest.config.mts
similarity index 100%
rename from fixtures/type-generation/vitest.config.ts
rename to fixtures/type-generation/vitest.config.mts
diff --git a/fixtures/vitest-pool-workers-examples/basics-unit-integration-self/test/fetch-integration-self.test.ts b/fixtures/vitest-pool-workers-examples/basics-unit-integration-self/test/fetch-integration-self.test.ts
index d7b66cdcc760..b6ac8dd69a62 100644
--- a/fixtures/vitest-pool-workers-examples/basics-unit-integration-self/test/fetch-integration-self.test.ts
+++ b/fixtures/vitest-pool-workers-examples/basics-unit-integration-self/test/fetch-integration-self.test.ts
@@ -3,7 +3,7 @@ import { expect, it } from "vitest";
 
 it("dispatches fetch event", async () => {
 	// `SELF` here points to the worker running in the current isolate.
-	// This gets its handler from the `main` option in `vitest.config.ts`.
+	// This gets its handler from the `main` option in `vitest.config.mts`.
 	// Importantly, it uses the exact `import("../src").default` instance we could
 	// import in this file as its handler.
 	const response = await SELF.fetch("http://example.com");
diff --git a/fixtures/vitest-pool-workers-examples/basics-unit-integration-self/test/scheduled-integration-self.test.ts b/fixtures/vitest-pool-workers-examples/basics-unit-integration-self/test/scheduled-integration-self.test.ts
index cac59d8dde9d..cddb6b00c665 100644
--- a/fixtures/vitest-pool-workers-examples/basics-unit-integration-self/test/scheduled-integration-self.test.ts
+++ b/fixtures/vitest-pool-workers-examples/basics-unit-integration-self/test/scheduled-integration-self.test.ts
@@ -3,7 +3,7 @@ import { expect, it } from "vitest";
 
 it("dispatches scheduled event", async () => {
 	// `SELF` here points to the worker running in the current isolate.
-	// This gets its handler from the `main` option in `vitest.config.ts`.
+	// This gets its handler from the `main` option in `vitest.config.mts`.
 	// Importantly, it uses the exact `import("../src").default` instance we could
 	// import in this file as its handler. Note the `SELF.scheduled()` method
 	// is experimental, and requires the `service_binding_extra_handlers`
diff --git a/fixtures/vitest-pool-workers-examples/d1/README.md b/fixtures/vitest-pool-workers-examples/d1/README.md
index c0b41494fc24..c6b6d910b29f 100644
--- a/fixtures/vitest-pool-workers-examples/d1/README.md
+++ b/fixtures/vitest-pool-workers-examples/d1/README.md
@@ -1,6 +1,6 @@
 # 📚 d1
 
-This Worker implements a simple blog using D1 bindings. It uses migrations for setting up the database. These migrations are read in `vitest.config.ts`, and applied with the [test/apply-migrations.ts](test/apply-migrations.ts) setup file.
+This Worker implements a simple blog using D1 bindings. It uses migrations for setting up the database. These migrations are read in `vitest.config.mts`, and applied with the [test/apply-migrations.ts](test/apply-migrations.ts) setup file.
 
 | Test                                    | Overview                         |
 | --------------------------------------- | -------------------------------- |
diff --git a/fixtures/vitest-pool-workers-examples/d1/test/env.d.ts b/fixtures/vitest-pool-workers-examples/d1/test/env.d.ts
index 1ccdbbe3d62f..d177afa47e0c 100644
--- a/fixtures/vitest-pool-workers-examples/d1/test/env.d.ts
+++ b/fixtures/vitest-pool-workers-examples/d1/test/env.d.ts
@@ -1,6 +1,6 @@
 declare module "cloudflare:test" {
 	// Controls the type of `import("cloudflare:test").env`
 	interface ProvidedEnv extends Env {
-		TEST_MIGRATIONS: D1Migration[]; // Defined in `vitest.config.ts`
+		TEST_MIGRATIONS: D1Migration[]; // Defined in `vitest.config.mts`
 	}
 }
diff --git a/fixtures/vitest-pool-workers-examples/hyperdrive/README.md b/fixtures/vitest-pool-workers-examples/hyperdrive/README.md
index 3660bfe287f0..74682d1d562f 100644
--- a/fixtures/vitest-pool-workers-examples/hyperdrive/README.md
+++ b/fixtures/vitest-pool-workers-examples/hyperdrive/README.md
@@ -1,6 +1,6 @@
 # 🚀 hyperdrive
 
-This Worker establishes a TCP connection with an echo server via Hyperdrive. The echo server is started/stopped by [global-setup.ts](global-setup.ts) on a random port, which is then provided to [vitest.config.ts](vitest.config.ts). In a real worker, Hyperdrive would be used with a database instead.
+This Worker establishes a TCP connection with an echo server via Hyperdrive. The echo server is started/stopped by [global-setup.ts](global-setup.ts) on a random port, which is then provided to [vitest.config.mts](vitest.config.mts). In a real worker, Hyperdrive would be used with a database instead.
 
 | Test                              | Overview                      |
 | --------------------------------- | ----------------------------- |
diff --git a/fixtures/vitest-pool-workers-examples/hyperdrive/wrangler.toml b/fixtures/vitest-pool-workers-examples/hyperdrive/wrangler.toml
index 0c52ae57da59..517015ad6bf9 100644
--- a/fixtures/vitest-pool-workers-examples/hyperdrive/wrangler.toml
+++ b/fixtures/vitest-pool-workers-examples/hyperdrive/wrangler.toml
@@ -6,4 +6,4 @@ compatibility_flags = ["nodejs_compat"]
 [[hyperdrive]]
 binding = "ECHO_SERVER_HYPERDRIVE"
 id = "00000000000000000000000000000000"
-localConnectionString = "postgres://user:pass@127.0.0.1/db" # Overridden in `vitest.config.ts`
+localConnectionString = "postgres://user:pass@127.0.0.1/db" # Overridden in `vitest.config.mts`
diff --git a/fixtures/vitest-pool-workers-examples/misc/test/defines.test.ts b/fixtures/vitest-pool-workers-examples/misc/test/defines.test.ts
index 5f904f51b518..9a6acd89a720 100644
--- a/fixtures/vitest-pool-workers-examples/misc/test/defines.test.ts
+++ b/fixtures/vitest-pool-workers-examples/misc/test/defines.test.ts
@@ -6,7 +6,7 @@ it("replaces defines from wrangler.toml", async () => {
 	expect(WRANGLER_NESTED.DEFINED.THING).toBe(WRANGLER_NESTED.DEFINED.THING);
 });
 
-it("replaces defines from vitest.config.ts", async () => {
+it("replaces defines from vitest.config.mts", async () => {
 	expect(CONFIG_DEFINED_THING).toBe("thing");
 	expect(CONFIG_NESTED.DEFINED.THING).toStrictEqual([1, 2, 3]);
 	expect(CONFIG_NESTED.DEFINED.THING).toBe(CONFIG_NESTED.DEFINED.THING);
diff --git a/fixtures/vitest-pool-workers-examples/multiple-workers/test/env.d.ts b/fixtures/vitest-pool-workers-examples/multiple-workers/test/env.d.ts
index 400bbd8bc8a6..4b8e62a89196 100644
--- a/fixtures/vitest-pool-workers-examples/multiple-workers/test/env.d.ts
+++ b/fixtures/vitest-pool-workers-examples/multiple-workers/test/env.d.ts
@@ -1,6 +1,6 @@
 declare module "cloudflare:test" {
 	// Controls the type of `import("cloudflare:test").env`
 	interface ProvidedEnv extends Env {
-		TEST_AUTH_PUBLIC_KEY: string; // Defined in `vitest.config.ts`
+		TEST_AUTH_PUBLIC_KEY: string; // Defined in `vitest.config.mts`
 	}
 }
diff --git a/fixtures/vitest-pool-workers-examples/pages-functions-unit-integration-self/test/integration-self.test.ts b/fixtures/vitest-pool-workers-examples/pages-functions-unit-integration-self/test/integration-self.test.ts
index 612a71d8234f..8234e0e17cbd 100644
--- a/fixtures/vitest-pool-workers-examples/pages-functions-unit-integration-self/test/integration-self.test.ts
+++ b/fixtures/vitest-pool-workers-examples/pages-functions-unit-integration-self/test/integration-self.test.ts
@@ -4,7 +4,7 @@ import { describe, expect, it } from "vitest";
 describe("functions", () => {
 	it("calls function", async () => {
 		// `SELF` here points to the worker running in the current isolate.
-		// This gets its handler from the `main` option in `vitest.config.ts`.
+		// This gets its handler from the `main` option in `vitest.config.mts`.
 		const response = await SELF.fetch("http://example.com/api/ping");
 		// All `/api/*` requests go through `functions/api/_middleware.ts`,
 		// which makes all response bodies uppercase
diff --git a/fixtures/vitest-pool-workers-examples/queues/test/queue-consumer-integration-self.test.ts b/fixtures/vitest-pool-workers-examples/queues/test/queue-consumer-integration-self.test.ts
index 6af377dabc1e..81a1809b238b 100644
--- a/fixtures/vitest-pool-workers-examples/queues/test/queue-consumer-integration-self.test.ts
+++ b/fixtures/vitest-pool-workers-examples/queues/test/queue-consumer-integration-self.test.ts
@@ -4,7 +4,7 @@ import { expect, it } from "vitest";
 
 it("consumes queue messages", async () => {
 	// `SELF` here points to the worker running in the current isolate.
-	// This gets its handler from the `main` option in `vitest.config.ts`.
+	// This gets its handler from the `main` option in `vitest.config.mts`.
 	// Importantly, it uses the exact `import("../src").default` instance we could
 	// import in this file as its handler. Note the `SELF.queue()` method
 	// is experimental, and requires the `service_binding_extra_handlers`
diff --git a/fixtures/vitest-pool-workers-examples/queues/test/queue-producer-unit.test.ts b/fixtures/vitest-pool-workers-examples/queues/test/queue-producer-unit.test.ts
index 96cef288877f..6e8c7d3e5070 100644
--- a/fixtures/vitest-pool-workers-examples/queues/test/queue-producer-unit.test.ts
+++ b/fixtures/vitest-pool-workers-examples/queues/test/queue-producer-unit.test.ts
@@ -41,7 +41,7 @@ it("produces queue message with mocked send", async () => {
 it("produces queue message with mocked consumer", async () => {
 	// Intercept calls to `worker.queue()`. Note the runner worker has a queue
 	// consumer configured that gets its handler from the `main` option in
-	// `vitest.config.ts`. Importantly, this uses the exact `worker` instance
+	// `vitest.config.mts`. Importantly, this uses the exact `worker` instance
 	// we're spying on here.
 	const consumerSpy = vi
 		.spyOn(worker, "queue")
diff --git a/fixtures/vitest-pool-workers-examples/queues/wrangler.toml b/fixtures/vitest-pool-workers-examples/queues/wrangler.toml
index 9d16ac6b78ce..222b39986c25 100644
--- a/fixtures/vitest-pool-workers-examples/queues/wrangler.toml
+++ b/fixtures/vitest-pool-workers-examples/queues/wrangler.toml
@@ -13,4 +13,4 @@ queue = "queue"
 
 [[queues.consumers]]
 queue = "queue"
-max_batch_timeout = 3 # Overridden in `vitest.config.ts`
+max_batch_timeout = 3 # Overridden in `vitest.config.mts`
diff --git a/fixtures/vitest-pool-workers-examples/vitest.workspace.ts b/fixtures/vitest-pool-workers-examples/vitest.workspace.ts
index 4c356ec93edc..ed4639590b61 100644
--- a/fixtures/vitest-pool-workers-examples/vitest.workspace.ts
+++ b/fixtures/vitest-pool-workers-examples/vitest.workspace.ts
@@ -1 +1 @@
-export default ["*/vitest.config.ts"];
+export default ["*/vitest.config.*ts"];
diff --git a/fixtures/worker-app/vitest.config.ts b/fixtures/worker-app/vitest.config.mts
similarity index 100%
rename from fixtures/worker-app/vitest.config.ts
rename to fixtures/worker-app/vitest.config.mts
diff --git a/lint-turbo.mjs b/lint-turbo.mjs
index 4c8a47df502f..5148a9c99ec1 100644
--- a/lint-turbo.mjs
+++ b/lint-turbo.mjs
@@ -31,7 +31,10 @@ for (const p of paths) {
 	}
 
 	// Ensure all packages with a vitest config file have a "test:ci" script
-	if (existsSync(path.join(p, "vitest.config.ts"))) {
+	if (
+		existsSync(path.join(p, "vitest.config.ts")) ||
+		existsSync(path.join(p, "vitest.config.mts"))
+	) {
 		assert(
 			pkg.scripts["test:ci"],
 			`Package "${p}" is missing a "test:ci" script in package.json`
diff --git a/packages/cli/vitest.config.ts b/packages/cli/vitest.config.mts
similarity index 100%
rename from packages/cli/vitest.config.ts
rename to packages/cli/vitest.config.mts
diff --git a/packages/create-cloudflare/package.json b/packages/create-cloudflare/package.json
index e45495b12ce5..61c978d58a2b 100644
--- a/packages/create-cloudflare/package.json
+++ b/packages/create-cloudflare/package.json
@@ -37,10 +37,10 @@
 		"test:e2e:pnpm": "pnpm run build && cross-env TEST_PM=pnpm vitest run --config ./vitest-e2e.config.ts",
 		"test:e2e:bun": "pnpm run build && cross-env TEST_PM=bun vitest run --config ./vitest-e2e.config.ts",
 		"test:e2e:yarn": "pnpm run build && cross-env TEST_PM=yarn vitest run --config ./vitest-e2e.config.ts",
-		"test:unit": "vitest run --config ./vitest.config.ts",
-		"test:unit:watch": "vitest --config ./vitest.config.ts",
+		"test:unit": "vitest run --config ./vitest.config.mts",
+		"test:unit:watch": "vitest --config ./vitest.config.mts",
 		"watch": "node -r esbuild-register scripts/build.ts --watch",
-		"test:ci": "vitest run --config ./vitest.config.ts"
+		"test:ci": "vitest run --config ./vitest.config.mts"
 	},
 	"devDependencies": {
 		"@babel/parser": "^7.21.3",
diff --git a/packages/create-cloudflare/templates/hello-world/ts/vitest.config.ts b/packages/create-cloudflare/templates/hello-world/ts/vitest.config.mts
similarity index 100%
rename from packages/create-cloudflare/templates/hello-world/ts/vitest.config.ts
rename to packages/create-cloudflare/templates/hello-world/ts/vitest.config.mts
diff --git a/packages/create-cloudflare/vitest.config.ts b/packages/create-cloudflare/vitest.config.mts
similarity index 100%
rename from packages/create-cloudflare/vitest.config.ts
rename to packages/create-cloudflare/vitest.config.mts
diff --git a/packages/edge-preview-authenticated-proxy/vitest.config.ts b/packages/edge-preview-authenticated-proxy/vitest.config.mts
similarity index 100%
rename from packages/edge-preview-authenticated-proxy/vitest.config.ts
rename to packages/edge-preview-authenticated-proxy/vitest.config.mts
diff --git a/packages/pages-shared/vitest.config.ts b/packages/pages-shared/vitest.config.mts
similarity index 100%
rename from packages/pages-shared/vitest.config.ts
rename to packages/pages-shared/vitest.config.mts
diff --git a/packages/vitest-pool-workers/.eslintrc.js b/packages/vitest-pool-workers/.eslintrc.js
index 2fc46348db1c..1410e90c546b 100644
--- a/packages/vitest-pool-workers/.eslintrc.js
+++ b/packages/vitest-pool-workers/.eslintrc.js
@@ -19,7 +19,7 @@ module.exports = {
 			},
 		},
 		{
-			files: "test/**/vitest.config.ts",
+			files: "test/**/vitest.config.*ts",
 			parserOptions: {
 				ecmaVersion: 2022,
 				sourceType: "module",
diff --git a/packages/vitest-pool-workers/src/worker/fetch-mock.ts b/packages/vitest-pool-workers/src/worker/fetch-mock.ts
index e3ff9585eb23..a97f67c3bcfa 100644
--- a/packages/vitest-pool-workers/src/worker/fetch-mock.ts
+++ b/packages/vitest-pool-workers/src/worker/fetch-mock.ts
@@ -37,7 +37,7 @@ setDispatcher((opts, handler) => {
 // worker. We kind of have to do it this way, as `fetchMock` supports functions
 // as reply callbacks, and we can't serialise arbitrary functions across worker
 // boundaries. For mocking requests in other workers, Miniflare's `fetchMock`
-// option can be used in the `vitest.config.ts`.
+// option can be used in the `vitest.config.mts`.
 globalThis.fetch = async (input, init) => {
 	const isActive = isMockActive(fetchMock);
 	if (!isActive) {
diff --git a/packages/vitest-pool-workers/test/chunking.test.ts b/packages/vitest-pool-workers/test/chunking.test.ts
index d48f688607a4..132cb856a5d4 100644
--- a/packages/vitest-pool-workers/test/chunking.test.ts
+++ b/packages/vitest-pool-workers/test/chunking.test.ts
@@ -10,7 +10,7 @@ test("chunks large WebSocket messages bi-directionally", async ({
 	const bigText = "xyz".repeat(400_000);
 	await seed({
 		"big.txt": bigText,
-		"vitest.config.ts": dedent`
+		"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			export default defineWorkersConfig({
 					test: {
diff --git a/packages/vitest-pool-workers/test/console.test.ts b/packages/vitest-pool-workers/test/console.test.ts
index 37e11572545e..7a9acfd68ed3 100644
--- a/packages/vitest-pool-workers/test/console.test.ts
+++ b/packages/vitest-pool-workers/test/console.test.ts
@@ -5,7 +5,7 @@ test.skipIf(process.platform === "win32")(
 	"console.log()s include correct source-mapped locations",
 	async ({ expect, seed, vitestDev }) => {
 		await seed({
-			"vitest.config.ts": minimalVitestConfig,
+			"vitest.config.mts": minimalVitestConfig,
 			"index.test.ts": dedent`
 			import { describe, it } from "vitest";
 			console.log("global");
@@ -59,7 +59,7 @@ test("console.logs() inside `export default`ed handlers with SELF", async ({
 	vitestRun,
 }) => {
 	await seed({
-		"vitest.config.ts": dedent`
+		"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			export default defineWorkersConfig({
 				test: {
diff --git a/packages/vitest-pool-workers/test/isolation.test.ts b/packages/vitest-pool-workers/test/isolation.test.ts
index 246b3cb4079a..aaee4a474486 100644
--- a/packages/vitest-pool-workers/test/isolation.test.ts
+++ b/packages/vitest-pool-workers/test/isolation.test.ts
@@ -29,7 +29,7 @@ test("isolated storage with multiple workers", async ({
 				}
 			}
 		`,
-		"vitest.config.ts": dedent`
+		"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			import { DeterministicSequencer } from "./sequencer.ts";
 
@@ -126,7 +126,7 @@ test("isolated storage with single worker", async ({
 				}
 			}
 		`,
-		"vitest.config.ts": dedent`
+		"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			import { DeterministicSequencer } from "./sequencer.ts";
 
@@ -235,7 +235,7 @@ test("shared storage with multiple workers", async ({
 				}
 			}
 		`,
-		"vitest.config.ts": dedent`
+		"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			import { DeterministicSequencer } from "./sequencer.ts";
 
@@ -327,7 +327,7 @@ test(
 				}
 			}
 		`,
-			"vitest.config.ts": dedent`
+			"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			import { DeterministicSequencer } from "./sequencer.ts";
 
diff --git a/packages/vitest-pool-workers/test/snapshots.test.ts b/packages/vitest-pool-workers/test/snapshots.test.ts
index 21d2a70d4f14..caa6c3aeb535 100644
--- a/packages/vitest-pool-workers/test/snapshots.test.ts
+++ b/packages/vitest-pool-workers/test/snapshots.test.ts
@@ -9,7 +9,7 @@ test(
 	async ({ expect, seed, vitestRun, tmpPath }) => {
 		// Check writes new snapshots
 		await seed({
-			"vitest.config.ts": minimalVitestConfig,
+			"vitest.config.mts": minimalVitestConfig,
 			"index.test.ts": dedent`
 			import { it, expect } from "vitest";
 			it("matches snapshot", () => {
@@ -117,7 +117,7 @@ test.skipIf(process.platform === "win32")(
 	async ({ expect, seed, vitestRun, tmpPath }) => {
 		// Check writes new snapshots
 		await seed({
-			"vitest.config.ts": minimalVitestConfig,
+			"vitest.config.mts": minimalVitestConfig,
 			"index.test.ts": dedent`
 			import { it, expect } from "vitest";
 			it("matches snapshot", () => {
@@ -146,7 +146,7 @@ test.skipIf(process.platform === "win32")(
 
 		// Check fails if snapshots differ
 		await seed({
-			"vitest.config.ts": minimalVitestConfig,
+			"vitest.config.mts": minimalVitestConfig,
 			"index.test.ts": dedent`
 			import { it, expect } from "vitest";
 			it("matches snapshot", () => {
diff --git a/packages/vitest-pool-workers/test/validation.test.ts b/packages/vitest-pool-workers/test/validation.test.ts
index f9487aa8881c..78357358c23a 100644
--- a/packages/vitest-pool-workers/test/validation.test.ts
+++ b/packages/vitest-pool-workers/test/validation.test.ts
@@ -9,7 +9,7 @@ test(
 
 		// Check top-level options validated
 		await seed({
-			"vitest.config.ts": dedent`
+			"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			export default defineWorkersConfig({
 				test: {
@@ -29,7 +29,7 @@ test(
 		let result = await vitestRun();
 		expect(await result.exitCode).toBe(1);
 		let expected = dedent`
-		TypeError: Unexpected pool options in project ${path.join(tmpPathName, "vitest.config.ts")}:
+		TypeError: Unexpected pool options in project ${path.join(tmpPathName, "vitest.config.mts")}:
 		{
 			test: {
 				poolOptions: {
@@ -51,7 +51,7 @@ test(
 
 		// Check `miniflare` options validated with correct error paths
 		await seed({
-			"vitest.config.ts": dedent`
+			"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			export default defineWorkersConfig({
 				test: {
@@ -70,7 +70,7 @@ test(
 		result = await vitestRun();
 		expect(await result.exitCode).toBe(1);
 		expected = dedent`
-		TypeError: Unexpected pool options in project ${path.join(tmpPathName, "vitest.config.ts")}:
+		TypeError: Unexpected pool options in project ${path.join(tmpPathName, "vitest.config.mts")}:
 		{
 			test: {
 				poolOptions: {
@@ -96,7 +96,7 @@ test(
 
 		// Check messages without Wrangler configuration path defined
 		await seed({
-			"vitest.config.ts": dedent`
+			"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			export default defineWorkersConfig({});
 		`,
@@ -105,13 +105,13 @@ test(
 		let result = await vitestRun();
 		expect(await result.exitCode).toBe(1);
 		let expected = dedent`
-		Error: In project ${path.join(tmpPathName, "vitest.config.ts")}, \`test.poolOptions.workers.miniflare.compatibilityFlags\` must contain "export_commonjs_default", or \`test.poolOptions.workers.miniflare.compatibilityDate\` must be >= "2022-10-31".
+		Error: In project ${path.join(tmpPathName, "vitest.config.mts")}, \`test.poolOptions.workers.miniflare.compatibilityFlags\` must contain "export_commonjs_default", or \`test.poolOptions.workers.miniflare.compatibilityDate\` must be >= "2022-10-31".
 		This flag is required to use \`@cloudflare/vitest-pool-workers\`.
 	`.replaceAll("\t", "  ");
 		expect(result.stderr).toMatch(expected);
 
 		await seed({
-			"vitest.config.ts": dedent`
+			"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			export default defineWorkersConfig({
 				test: {
@@ -127,14 +127,14 @@ test(
 		result = await vitestRun();
 		expect(await result.exitCode).toBe(1);
 		expected = dedent`
-		Error: In project ${path.join(tmpPathName, "vitest.config.ts")}, \`test.poolOptions.workers.miniflare.compatibilityFlags\` must contain "nodejs_compat".
+		Error: In project ${path.join(tmpPathName, "vitest.config.mts")}, \`test.poolOptions.workers.miniflare.compatibilityFlags\` must contain "nodejs_compat".
 		This flag is required to use \`@cloudflare/vitest-pool-workers\`.
 	`.replaceAll("\t", "  ");
 		expect(result.stderr).toMatch(expected);
 
 		// Check messages with Wrangler configuration path defined
 		await seed({
-			"vitest.config.ts": dedent`
+			"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			export default defineWorkersConfig({
 				test: {
@@ -151,7 +151,7 @@ test(
 		result = await vitestRun();
 		expect(await result.exitCode).toBe(1);
 		expected = dedent`
-		Error: In project ${path.join(tmpPathName, "vitest.config.ts")}'s configuration file ${path.join(tmpPathName, "wrangler.toml")}, \`compatibility_flags\` must contain "export_commonjs_default", or \`compatibility_date\` must be >= "2022-10-31".
+		Error: In project ${path.join(tmpPathName, "vitest.config.mts")}'s configuration file ${path.join(tmpPathName, "wrangler.toml")}, \`compatibility_flags\` must contain "export_commonjs_default", or \`compatibility_date\` must be >= "2022-10-31".
 		This flag is required to use \`@cloudflare/vitest-pool-workers\`.
 	`.replaceAll("\t", "  ");
 		expect(result.stderr).toMatch(expected);
@@ -164,7 +164,7 @@ test(
 		result = await vitestRun();
 		expect(await result.exitCode).toBe(1);
 		expected = dedent`
-		Error: In project ${path.join(tmpPathName, "vitest.config.ts")}'s configuration file ${path.join(tmpPathName, "wrangler.toml")}, \`compatibility_flags\` must contain "nodejs_compat".
+		Error: In project ${path.join(tmpPathName, "vitest.config.mts")}'s configuration file ${path.join(tmpPathName, "wrangler.toml")}, \`compatibility_flags\` must contain "nodejs_compat".
 		This flag is required to use \`@cloudflare/vitest-pool-workers\`.
 	`.replaceAll("\t", "  ");
 		expect(result.stderr).toMatch(expected);
@@ -179,7 +179,7 @@ test(
 
 		// Check with no entrypoint
 		await seed({
-			"vitest.config.ts": dedent`
+			"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			export default defineWorkersConfig({
 				test: {
@@ -213,7 +213,7 @@ test(
 
 		// Check with service worker
 		await seed({
-			"vitest.config.ts": dedent`
+			"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			export default defineWorkersConfig({
 				test: {
diff --git a/packages/vitest-pool-workers/test/watch.test.ts b/packages/vitest-pool-workers/test/watch.test.ts
index 5781714c7787..e0d846144323 100644
--- a/packages/vitest-pool-workers/test/watch.test.ts
+++ b/packages/vitest-pool-workers/test/watch.test.ts
@@ -7,7 +7,7 @@ test("automatically re-runs unit tests", async ({
 	vitestDev,
 }) => {
 	await seed({
-		"vitest.config.ts": minimalVitestConfig,
+		"vitest.config.mts": minimalVitestConfig,
 		"index.ts": dedent`
 			export default {
 				async fetch(request, env, ctx) {
@@ -54,7 +54,7 @@ test("automatically re-runs integration tests", async ({
 	vitestDev,
 }) => {
 	await seed({
-		"vitest.config.ts": dedent`
+		"vitest.config.mts": dedent`
 			import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
 			export default defineWorkersConfig({
 				test: {
diff --git a/packages/vitest-pool-workers/tsconfig.json b/packages/vitest-pool-workers/tsconfig.json
index f16ed68962ee..0240c5ea0c1b 100644
--- a/packages/vitest-pool-workers/tsconfig.json
+++ b/packages/vitest-pool-workers/tsconfig.json
@@ -15,7 +15,7 @@
 		"./src/pool/**/*.ts",
 		"./src/shared/**/*.ts",
 		"./test/**/*.ts",
-		"./vitest.config.ts",
+		"./vitest.config.*ts",
 		"./vitest.workspace.ts"
 	]
 }
diff --git a/packages/vitest-pool-workers/vitest.config.ts b/packages/vitest-pool-workers/vitest.config.mts
similarity index 100%
rename from packages/vitest-pool-workers/vitest.config.ts
rename to packages/vitest-pool-workers/vitest.config.mts
diff --git a/packages/workers.new/vitest.config.ts b/packages/workers.new/vitest.config.mts
similarity index 100%
rename from packages/workers.new/vitest.config.ts
rename to packages/workers.new/vitest.config.mts
diff --git a/packages/wrangler/e2e/vitest.config.ts b/packages/wrangler/e2e/vitest.config.mts
similarity index 100%
rename from packages/wrangler/e2e/vitest.config.ts
rename to packages/wrangler/e2e/vitest.config.mts
diff --git a/packages/wrangler/package.json b/packages/wrangler/package.json
index 45001bdd04ca..596b6c22e611 100644
--- a/packages/wrangler/package.json
+++ b/packages/wrangler/package.json
@@ -64,7 +64,7 @@
 		"test": "pnpm run assert-git-version && vitest",
 		"test:ci": "pnpm run test run",
 		"test:debug": "pnpm run test --silent=false --verbose=true",
-		"test:e2e": "vitest -c ./e2e/vitest.config.ts",
+		"test:e2e": "vitest -c ./e2e/vitest.config.mts",
 		"test:watch": "pnpm run test --testTimeout=50000 --watch",
 		"type:tests": "tsc -p ./src/__tests__/tsconfig.json && tsc -p ./e2e/tsconfig.json"
 	},
diff --git a/packages/wrangler/vitest.config.ts b/packages/wrangler/vitest.config.mts
similarity index 100%
rename from packages/wrangler/vitest.config.ts
rename to packages/wrangler/vitest.config.mts
diff --git a/tools/vitest.config.ts b/tools/vitest.config.mts
similarity index 100%
rename from tools/vitest.config.ts
rename to tools/vitest.config.mts
diff --git a/vitest.workspace.ts b/vitest.workspace.ts
index edbed77fe47a..3095a872ee14 100644
--- a/vitest.workspace.ts
+++ b/vitest.workspace.ts
@@ -1,5 +1,5 @@
 export default [
-	"packages/*/vitest.config.ts",
-	"fixtures/*/vitest.config.ts",
-	"tools/vitest.config.ts",
+	"packages/*/vitest.config.mts",
+	"fixtures/*/vitest.config.mts",
+	"tools/vitest.config.mts",
 ];