better support for duplicate headers for format 2.0, shoud fix #125

Author: adrai

index.js

@@ -52,9 +52,19 @@ module.exports = (app, options) => {
       } else if (event.queryStringParameters) {
         Object.keys(event.queryStringParameters).forEach((q) => {
           query[decodeURIComponent(q)] = decodeURIComponent(event.queryStringParameters[q])
+          if (typeof query[decodeURIComponent(q)] === 'string' && query[decodeURIComponent(q)].indexOf(',') > 0) {
+            query[decodeURIComponent(q)] = query[decodeURIComponent(q)].split(',')
+          }
         })
       }
     } else {
+      if (event.queryStringParameters) {
+        Object.keys(event.queryStringParameters).forEach((k) => {
+          if (typeof event.queryStringParameters[k] === 'string' && event.queryStringParameters[k].indexOf(',') > 0) {
+            event.queryStringParameters[k] = event.queryStringParameters[k].split(',')
+          }
+        })
+      }
       Object.assign(query, event.multiValueQueryStringParameters || event.queryStringParameters)
     }
     const headers = Object.assign({}, event.headers)

test/basic.test.js

@@ -184,6 +184,26 @@ test('GET with multi-value query params', async (t) => {
   t.equal(ret.body, '{"foo":["qux","bar"]}')
 })
 
+test('GET with multi-value query params (queryStringParameters)', async (t) => {
+  t.plan(2)
+
+  const app = fastify()
+  app.get('/test', async (request, reply) => {
+    reply.send(request.query)
+  })
+  const proxy = awsLambdaFastify(app)
+
+  const ret = await proxy({
+    httpMethod: 'GET',
+    path: '/test',
+    queryStringParameters: {
+      foo: 'qux,bar'
+    }
+  })
+  t.equal(ret.statusCode, 200)
+  t.equal(ret.body, '{"foo":["qux","bar"]}')
+})
+
 test('GET with double encoded query value', async (t) => {
   t.plan(2)