Support msw v2 and custom server implementations

README.md

@@ -142,6 +142,31 @@ const tearDown = async ({ jwksMock, server }) => {
 
 You can also find [this example in the repo](example/authentication.test.js).
 
+### Custom Mock Server Worker (MSW) usage
+
+Internally this library uses Mock Server Worker (MSW) to create network mocks
+for the JWKS keyset. This can cause issues if you're already using MSW because
+running multiple MSW server instances is not recommended.
+
+In this case, instead of calling `start()/stop()`, use the `jwksHandler()` 
+function to create an MSW handler you can add to your existing server
+instance. Like this:
+
+```typescript
+// Import your existing global msw server
+import { server } from "./msw-server.js";
+
+describe("example reusing global msw server", () => {
+  beforeEach(() => {
+    // Prepend the jwks handler to the server
+    server.use(jwksMock.jwksHandler())
+  })
+  test("does something requiring jwks", () => {
+    // Test logic
+  })
+})
+```
+
 ## Under the hood
 
 `createJWKSMock` will create a local PKI and generate a working JWKS.json. Calling `jwksMock.start()` will use [msw](https://mswjs.io/)

package.json

@@ -91,7 +91,7 @@
   "dependencies": {
     "base64-url": "^2.3.3",
     "jsonwebtoken": "^9.0.0",
-    "msw": "^1.2.2",
+    "msw": "^2.3.1",
     "node-forge": "^1.3.1",
     "node-rsa": "^1.1.1"
   },

src/index.ts

@@ -1,22 +1,24 @@
 import { JwtPayload } from 'jsonwebtoken'
 import { createJWKS, createKeyPair, signJwt } from './tools.js'
 import { setupServer } from 'msw/node'
-import { rest } from 'msw'
+import { HttpResponse, http, RequestHandlerOptions, HttpHandler } from 'msw'
 
 const createJWKSMock = (
   jwksBase: string,
   jwksPath = '/.well-known/jwks.json'
-) => {
+): JWKSMock => {
   const keypair = createKeyPair()
   const JWKS = createJWKS({
     ...keypair,
     jwksOrigin: jwksBase,
   })
-  const server = setupServer(
-    rest.get(new URL(jwksPath, jwksBase).href, (_, res, ctx) =>
-      res(ctx.status(200), ctx.json(JWKS))
+  const jwksHandler = (options?: RequestHandlerOptions) =>
+    http.get(
+      new URL(jwksPath, jwksBase).href,
+      () => HttpResponse.json(JWKS),
+      options
     )
-  )
+  const server = setupServer(jwksHandler())
 
   const kid = () => JWKS.keys[0].kid
 
@@ -35,9 +37,16 @@ const createJWKSMock = (
     stop,
     kid,
     token,
+    jwksHandler,
   }
 }
 
-export type JWKSMock = ReturnType<typeof createJWKSMock>
+export type JWKSMock = {
+  start: () => void
+  stop: () => void
+  kid: () => string
+  token: (token: JwtPayload) => string
+  jwksHandler: (options?: RequestHandlerOptions) => HttpHandler
+}
 
 export default createJWKSMock

src/jwksRsa.test.ts

@@ -1,19 +1,19 @@
 import JWT from 'jsonwebtoken'
 import jwksClient, { CertSigningKey, RsaSigningKey } from 'jwks-rsa'
-import createAuth0Mock from './index.js'
+import createAuth0Mock, { type JWKSMock } from './index.js'
 import pify from 'pify'
 import { beforeEach, describe, expect, test } from 'vitest'
+import { setupServer } from 'msw/node'
 
-const auth0Mock = createAuth0Mock('https://hardfork.eu.auth0.com')
-const client = jwksClient({
-  jwksUri: 'https://hardfork.eu.auth0.com/.well-known/jwks.json',
-})
-
-describe('Tests for JWKS being correctly consumed by jwks-rsa client', () => {
-  beforeEach(() => {
-    auth0Mock.start()
-    return auth0Mock.stop
+const initialise = () => {
+  const auth0Mock = createAuth0Mock('https://hardfork.eu.auth0.com')
+  const client = jwksClient({
+    jwksUri: 'https://hardfork.eu.auth0.com/.well-known/jwks.json',
   })
+  return { auth0Mock, client }
+}
+
+const rsaClientTests = (auth0Mock: JWKSMock, client: jwksClient.JwksClient) => {
   test('mock returns a signing key', () =>
     expect(pify(client.getSigningKey)(auth0Mock.kid())).resolves.toBeTruthy())
   test('generated token should be valid against the JWKS key', async () => {
@@ -86,4 +86,29 @@ describe('Tests for JWKS being correctly consumed by jwks-rsa client', () => {
         'delete:all',
       ],
     }))
+}
+
+describe('Tests for JWKS being correctly consumed by jwks-rsa client', () => {
+  describe('Using built-in msw server mocks', () => {
+    const { auth0Mock, client } = initialise()
+
+    beforeEach(() => {
+      auth0Mock.start()
+      return auth0Mock.stop
+    })
+
+    rsaClientTests(auth0Mock, client)
+  })
+
+  describe('Using custom msw server mocks', () => {
+    const { auth0Mock, client } = initialise()
+
+    beforeEach(() => {
+      const server = setupServer(auth0Mock.jwksHandler())
+      server.listen()
+      return () => server.close()
+    })
+
+    rsaClientTests(auth0Mock, client)
+  })
 })