fix: lambda integration returning object with body (#1547)

src/events/http/HttpServer.js

@@ -788,12 +788,6 @@ export default class HttpServer {
           response.variety = 'buffer'
         } else if (typeof result === 'string') {
           response.source = stringify(result)
-        } else if (result && result.body && typeof result.body !== 'string') {
-          return this.#reply502(
-            response,
-            'According to the API Gateway specs, the body content must be stringified. Check your Lambda response and make sure you are invoking JSON.stringify(YOUR_CONTENT) on your body object',
-            {},
-          )
         } else {
           response.source = result
         }
@@ -888,6 +882,7 @@ export default class HttpServer {
             response.variety = 'buffer'
           } else {
             if (result && result.body && typeof result.body !== 'string') {
+              // FIXME TODO we should probably just write to console instead of returning a payload
               return this.#reply502(
                 response,
                 'According to the API Gateway specs, the body content must be stringified. Check your Lambda response and make sure you are invoking JSON.stringify(YOUR_CONTENT) on your body object',

tests/integration/lambda-integration/lambdaIntegration.test.js

@@ -28,6 +28,19 @@ describe('lambda integration tests', function desc() {
       status: 200,
     },
 
+    // https://github.com/dherault/serverless-offline/issues/1502
+    {
+      description: 'should return JSON',
+      expected: {
+        body: {
+          foo: 'bar',
+        },
+        statusCode: 200,
+      },
+      path: '/dev/lambda-integration-json-with-body',
+      status: 200,
+    },
+
     {
       description: 'should return stringified JSON',
       expected: stringify({

tests/integration/lambda-integration/serverless.yml

@@ -22,6 +22,14 @@ functions:
           path: '/lambda-integration-json'
     handler: src/handler.lambdaIntegrationJson
 
+  integrationJsonWithBody:
+    events:
+      - http:
+          integration: lambda
+          method: get
+          path: '/lambda-integration-json-with-body'
+    handler: src/handler.lambdaIntegrationJsonWithBody
+
   integrationStringified:
     events:
       - http:

tests/integration/lambda-integration/src/handler.js

@@ -8,6 +8,16 @@ exports.lambdaIntegrationJson = async function lambdaIntegrationJson() {
   }
 }
 
+exports.lambdaIntegrationJsonWithBody =
+  async function lambdaIntegrationJsonWithBody() {
+    return {
+      body: {
+        foo: 'bar',
+      },
+      statusCode: 200,
+    }
+  }
+
 exports.lambdaIntegrationStringified =
   async function lambdaIntegrationStringified() {
     return stringify({