Add option to retain the API Gateway stage in the URL passed to fastify (#164)

* adds option to retain stage part of the url

* added test for retain stage

Author: Thorkil Holm-Jacobsen

README.md

@@ -20,14 +20,15 @@ $ npm i @fastify/aws-lambda
 
 **@fastify/aws-lambda** can take options by passing them with : `awsLambdaFastify(app, options)`
 
-| property                       | description                                                                                                                          | default value |
-| ------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------ | ------------- |
-| binaryMimeTypes                | Array of binary MimeTypes to handle                                                                                                  | `[]`          |
-| enforceBase64                  | Function that receives the response and returns a boolean indicating if the response content is binary or not and should be base64-encoded                          | `undefined`   |
-| serializeLambdaArguments       | Activate the serialization of lambda Event and Context in http header `x-apigateway-event` `x-apigateway-context`                    | `false` *(was `true` for <v2.0.0)*        |
-| decorateRequest       | Decorates the fastify request with the lambda Event and Context `request.awsLambda.event` `request.awsLambda.context`                    | `true`        |
-| decorationPropertyName       | The default property name for request decoration                    | `awsLambda`        |
-| callbackWaitsForEmptyEventLoop | See: [Official Documentation](https://docs.aws.amazon.com/lambda/latest/dg/nodejs-context.html#nodejs-prog-model-context-properties) | `undefined`   |
+| property                       | description                                                                                                                                | default value                      |
+| ------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------- |
+| binaryMimeTypes                | Array of binary MimeTypes to handle                                                                                                        | `[]`                               |
+| enforceBase64                  | Function that receives the response and returns a boolean indicating if the response content is binary or not and should be base64-encoded | `undefined`                        |
+| serializeLambdaArguments       | Activate the serialization of lambda Event and Context in http header `x-apigateway-event` `x-apigateway-context`                          | `false` *(was `true` for <v2.0.0)* |
+| decorateRequest                | Decorates the fastify request with the lambda Event and Context `request.awsLambda.event` `request.awsLambda.context`                      | `true`                             |
+| decorationPropertyName         | The default property name for request decoration                                                                                           | `awsLambda`                        |
+| callbackWaitsForEmptyEventLoop | See: [Official Documentation](https://docs.aws.amazon.com/lambda/latest/dg/nodejs-context.html#nodejs-prog-model-context-properties)       | `undefined`                        |
+| retainStage                    | Retain the stage part of the API Gateway URL                                                                                               | `false`                            |
 
 ## 📖Example
 

index.js

@@ -15,6 +15,7 @@ module.exports = (app, options) => {
   options.binaryMimeTypes = options.binaryMimeTypes || []
   options.serializeLambdaArguments = options.serializeLambdaArguments !== undefined ? options.serializeLambdaArguments : false
   options.decorateRequest = options.decorateRequest !== undefined ? options.decorateRequest : true
+  options.retainStage = options.retainStage !== undefined ? options.retainStage : false
   let currentAwsArguments = {}
   if (options.decorateRequest) {
     options.decorationPropertyName = options.decorationPropertyName || 'awsLambda'
@@ -40,8 +41,8 @@ module.exports = (app, options) => {
     const method = event.httpMethod || (event.requestContext && event.requestContext.http ? event.requestContext.http.method : undefined)
     let url = event.path || event.rawPath || '/' // seen rawPath for HTTP-API
     // NOTE: if used directly via API Gateway domain and /stage
-    if (event.requestContext && event.requestContext.stage && event.requestContext.resourcePath &&
-        (url).indexOf(`/${event.requestContext.stage}/`) === 0 &&
+    if (!options.retainStage && event.requestContext && event.requestContext.stage &&
+        event.requestContext.resourcePath && (url).indexOf(`/${event.requestContext.stage}/`) === 0 &&
         event.requestContext.resourcePath.indexOf(`/${event.requestContext.stage}/`) !== 0) {
       url = url.substring(event.requestContext.stage.length + 1)
     }

test/basic.test.js

@@ -351,6 +351,36 @@ test('subpath', async (t) => {
   t.same(ret.multiValueHeaders['set-cookie'], ['qwerty=one', 'qwerty=two'])
 })
 
+test('subpath retain stage', async (t) => {
+  t.plan(7)
+
+  const app = fastify()
+  app.get('/dev/test', async (request, reply) => {
+    t.equal(request.headers['x-my-header'], 'wuuusaaa')
+    t.equal(request.headers['x-apigateway-event'], '%7B%22httpMethod%22%3A%22GET%22%2C%22path%22%3A%22%2Fdev%2Ftest%22%2C%22headers%22%3A%7B%22X-My-Header%22%3A%22wuuusaaa%22%7D%2C%22requestContext%22%3A%7B%22resourcePath%22%3A%22%2Ftest%22%2C%22stage%22%3A%22dev%22%7D%7D')
+    t.equal(request.headers['user-agent'], 'lightMyRequest')
+    t.equal(request.headers.host, 'localhost:80')
+    t.equal(request.headers['content-length'], '0')
+    reply.header('Set-Cookie', 'qwerty=one')
+    reply.header('Set-Cookie', 'qwerty=two')
+    reply.send({ hello: 'world' })
+  })
+  const proxy = awsLambdaFastify(app, { retainStage: true, serializeLambdaArguments: true })
+  const ret = await proxy({
+    httpMethod: 'GET',
+    path: '/dev/test',
+    headers: {
+      'X-My-Header': 'wuuusaaa'
+    },
+    requestContext: {
+      resourcePath: '/test',
+      stage: 'dev'
+    }
+  })
+  t.equal(ret.statusCode, 200)
+  t.equal(ret.body, '{"hello":"world"}')
+})
+
 test('serializeLambdaArguments = false', async (t) => {
   t.plan(14)
 

types/index.d.ts

@@ -11,6 +11,7 @@ declare namespace awsLambdaFastify {
     decorateRequest?: boolean;
     decorationPropertyName?: string;
     enforceBase64?: (response: LightMyRequestResponse) => boolean;
+    retainStage?: boolean;
   }
 
   export interface LambdaResponse {

types/index.test-d.ts

@@ -75,6 +75,18 @@ expectAssignable<LambdaFastifyOptions>({
       return false;
   },
 });
+expectAssignable<LambdaFastifyOptions>({
+  binaryMimeTypes: ["foo", "bar"],
+  callbackWaitsForEmptyEventLoop: true,
+  serializeLambdaArguments: false,
+  decorateRequest: true,
+  decorationPropertyName: "myAWSstuff",
+  enforceBase64: (response) => {
+      expectType<LightMyRequestResponse>(response);
+      return false;
+  },
+  retainStage: true,
+});
 
 expectError(awsLambdaFastify());
 expectError(awsLambdaFastify(app, { neh: "definition" }));