feat: generating callbackUri on fly (#258)

* Support FastifyRequest => string as callbackUri option

* Add "callbackUri as function" test

Author: wlinna

README.md

@@ -34,6 +34,8 @@ fastify.register(oauthPlugin, {
   startRedirectPath: '/login/facebook',
   // facebook redirect here after the user login
   callbackUri: 'http://localhost:3000/login/facebook/callback'
+  // You can also define callbackUri as a function that takes a FastifyRequest and returns a string
+  // callbackUri: req => `${req.protocol}://${req.hostname}/login/facebook/callback`,
 })
 
 fastify.get('/login/facebook/callback', async function (request, reply) {

index.js

@@ -50,8 +50,8 @@ function fastifyOauth2 (fastify, options, next) {
   if (typeof options.credentials !== 'object') {
     return next(new Error('options.credentials should be an object'))
   }
-  if (typeof options.callbackUri !== 'string') {
-    return next(new Error('options.callbackUri should be a string'))
+  if (typeof options.callbackUri !== 'string' && typeof options.callbackUri !== 'function') {
+    return next(new Error('options.callbackUri should be a string or a function'))
   }
   if (options.callbackUriParams && typeof options.callbackUriParams !== 'object') {
     return next(new Error('options.callbackUriParams should be a object'))
@@ -168,7 +168,7 @@ function fastifyOauth2 (fastify, options, next) {
         }
 
         const urlOptions = Object.assign({}, generateCallbackUriParams(callbackUriParams, request, scope, state), {
-          redirect_uri: callbackUri,
+          redirect_uri: typeof callbackUri === 'function' ? callbackUri(request) : callbackUri,
           scope,
           state
         }, pkceParams)
@@ -198,10 +198,10 @@ function fastifyOauth2 (fastify, options, next) {
       })
     }
 
-    const cbk = function (o, code, pkceParams, callback) {
+    const cbk = function (o, request, code, pkceParams, callback) {
       const body = Object.assign({}, tokenRequestParams, {
         code,
-        redirect_uri: callbackUri
+        redirect_uri: typeof callbackUri === 'function' ? callbackUri(request) : callbackUri
       }, pkceParams)
 
       return callbackify(o.oauth2.getToken.bind(o.oauth2, body))(callback)
@@ -241,7 +241,7 @@ function fastifyOauth2 (fastify, options, next) {
           callback(err)
           return
         }
-        cbk(fastify[name], code, pkceParams, _callback)
+        cbk(fastify[name], request, code, pkceParams, _callback)
       })
     }
 

test/index.test.js

@@ -210,6 +210,51 @@ t.test('fastify-oauth2', t => {
     makeRequests(t, fastify)
   })
 
+  t.test('callbackUri as function', t => {
+    const fastify = createFastify({ logger: { level: 'silent' } })
+
+    fastify.register(fastifyOauth2, {
+      name: 'githubOAuth2',
+      credentials: {
+        client: {
+          id: 'my-client-id',
+          secret: 'my-secret'
+        },
+        auth: fastifyOauth2.GITHUB_CONFIGURATION
+      },
+      startRedirectPath: '/login/github',
+      callbackUri: req => `${req.protocol}://localhost:3000/callback`,
+      scope: ['notifications']
+    })
+
+    fastify.get('/', function (request, reply) {
+      if (this.githubOAuth2 !== this.oauth2GithubOAuth2) {
+        throw new Error('Expected oauth2GithubOAuth2 to match githubOAuth2')
+      }
+      this.githubOAuth2.getAccessTokenFromAuthorizationCodeFlow(request, (err, result) => {
+        if (err) throw err
+
+        // attempts to refresh the token
+        this.githubOAuth2.getNewAccessTokenUsingRefreshToken(result.token, undefined, (err, result) => {
+          if (err) throw err
+
+          const newToken = result
+
+          reply.send({
+            access_token: newToken.token.access_token,
+            refresh_token: newToken.token.refresh_token,
+            expires_in: newToken.token.expires_in,
+            token_type: newToken.token.token_type
+          })
+        })
+      })
+    })
+
+    t.teardown(fastify.close.bind(fastify))
+
+    makeRequests(t, fastify)
+  })
+
   t.test('promise', t => {
     const fastify = createFastify({ logger: { level: 'silent' } })
 
@@ -1399,7 +1444,7 @@ t.test('options.credentials should be an object', t => {
     })
 })
 
-t.test('options.callbackUri should be an object', t => {
+t.test('options.callbackUri should be a string or a function', t => {
   t.plan(1)
 
   const fastify = createFastify({ logger: { level: 'silent' } })
@@ -1415,7 +1460,7 @@ t.test('options.callbackUri should be an object', t => {
     }
   })
     .ready(err => {
-      t.strictSame(err.message, 'options.callbackUri should be a string')
+      t.strictSame(err.message, 'options.callbackUri should be a string or a function')
     })
 })
 

types/index.d.ts

@@ -34,7 +34,7 @@ declare namespace fastifyOauth2 {
     name: string;
     scope?: string[];
     credentials: Credentials;
-    callbackUri: string;
+    callbackUri: string | ((req: FastifyRequest) => string);
     callbackUriParams?: Object;
     tokenRequestParams?: Object;
     generateStateFunction?: FastifyGenerateStateFunction;

types/index.test-d.ts

@@ -70,6 +70,16 @@ expectAssignable<FastifyOAuth2Options>({
     pkce: 'S256'
 })
 
+expectAssignable<FastifyOAuth2Options>({
+    name: 'testOAuthName',
+    scope: scope,
+    credentials: credentials,
+    callbackUri: req => `${req.protocol}://${req.hostname}/callback`,
+    callbackUriParams: {},
+    startRedirectPath: '/login/testOauth',
+    pkce: 'S256'
+})
+
 expectAssignable<FastifyOAuth2Options>({
     name: 'testOAuthName',
     scope: scope,