fix(event-handler): handle nullable fields in APIGatewayProxyEvent (#4455)

Author: svozza

packages/event-handler/src/rest/utils.ts

@@ -75,10 +75,17 @@ export const isAPIGatewayProxyEvent = (
     isString(event.httpMethod) &&
     isString(event.path) &&
     isString(event.resource) &&
-    isRecord(event.headers) &&
+    (event.headers == null || isRecord(event.headers)) &&
+    (event.multiValueHeaders == null || isRecord(event.multiValueHeaders)) &&
     isRecord(event.requestContext) &&
     typeof event.isBase64Encoded === 'boolean' &&
-    (event.body === null || isString(event.body))
+    (event.body === null || isString(event.body)) &&
+    (event.pathParameters === null || isRecord(event.pathParameters)) &&
+    (event.queryStringParameters === null ||
+      isRecord(event.queryStringParameters)) &&
+    (event.multiValueQueryStringParameters === null ||
+      isRecord(event.multiValueQueryStringParameters)) &&
+    (event.stageVariables === null || isRecord(event.stageVariables))
   );
 };
 

packages/event-handler/tests/unit/rest/utils.test.ts

@@ -214,45 +214,105 @@ describe('Path Utilities', () => {
   });
 
   describe('isAPIGatewayProxyEvent', () => {
-    it('should return true for valid API Gateway Proxy event', () => {
-      const validEvent: APIGatewayProxyEvent = {
-        httpMethod: 'GET',
+    const baseValidEvent = {
+      httpMethod: 'GET',
+      path: '/test',
+      resource: '/test',
+      headers: {},
+      multiValueHeaders: {},
+      queryStringParameters: {},
+      multiValueQueryStringParameters: {},
+      pathParameters: {},
+      stageVariables: {},
+      requestContext: { stage: 'test' },
+      isBase64Encoded: false,
+      body: null,
+    };
+
+    it('should return true for valid API Gateway Proxy event with all fields populated', () => {
+      expect(isAPIGatewayProxyEvent(baseValidEvent)).toBe(true);
+    });
+
+    it('should return true for real API Gateway event with null fields', () => {
+      const realEvent = {
+        resource: '/{proxy+}',
         path: '/test',
-        resource: '/test',
-        headers: {},
+        httpMethod: 'GET',
+        headers: null,
+        multiValueHeaders: null,
+        queryStringParameters: null,
+        multiValueQueryStringParameters: null,
+        pathParameters: { proxy: 'test' },
+        stageVariables: null,
         requestContext: {
-          accountId: '123456789012',
-          apiId: 'test-api',
+          resourceId: 'ovdb9g',
+          resourcePath: '/{proxy+}',
           httpMethod: 'GET',
-          requestId: 'test-request-id',
-          resourceId: 'test-resource',
-          resourcePath: '/test',
-          stage: 'test',
-          identity: {
-            sourceIp: '127.0.0.1',
-          },
-        } as any,
-        isBase64Encoded: false,
+          stage: 'test-invoke-stage',
+          requestId: 'eecdfcfa-225a-4ee3-bdca-05fc31b6018a',
+          identity: { sourceIp: 'test-invoke-source-ip' },
+        },
         body: null,
-      } as APIGatewayProxyEvent;
+        isBase64Encoded: false,
+      };
 
-      expect(isAPIGatewayProxyEvent(validEvent)).toBe(true);
+      expect(isAPIGatewayProxyEvent(realEvent)).toBe(true);
     });
 
-    it('should return true for valid event with string body', () => {
-      const validEvent = {
+    it('should return true for event with string body', () => {
+      const eventWithBody = {
+        ...baseValidEvent,
         httpMethod: 'POST',
-        path: '/test',
-        resource: '/test',
-        headers: { 'content-type': 'application/json' },
-        requestContext: { stage: 'test' },
-        isBase64Encoded: false,
         body: '{"key":"value"}',
       };
 
-      expect(isAPIGatewayProxyEvent(validEvent)).toBe(true);
+      expect(isAPIGatewayProxyEvent(eventWithBody)).toBe(true);
     });
 
+    it.each([
+      // Headers can be null in reality (even though types say otherwise)
+      { field: 'headers', value: null },
+      { field: 'headers', value: undefined },
+      { field: 'multiValueHeaders', value: null },
+      { field: 'multiValueHeaders', value: undefined },
+      // These are officially nullable in the type definition
+      { field: 'body', value: null },
+      { field: 'pathParameters', value: null },
+      { field: 'queryStringParameters', value: null },
+      { field: 'multiValueQueryStringParameters', value: null },
+      { field: 'stageVariables', value: null },
+    ])('should return true when $field is $value', ({ field, value }) => {
+      const event = { ...baseValidEvent, [field]: value };
+      expect(isAPIGatewayProxyEvent(event)).toBe(true);
+    });
+
+    it.each([
+      {
+        field: 'headers',
+        value: { 'content-type': undefined, 'x-api-key': 'test' },
+      },
+      {
+        field: 'multiValueHeaders',
+        value: { accept: undefined, 'x-custom': ['val1', 'val2'] },
+      },
+      { field: 'pathParameters', value: { id: undefined, name: 'test' } },
+      {
+        field: 'queryStringParameters',
+        value: { filter: undefined, sort: 'asc' },
+      },
+      {
+        field: 'multiValueQueryStringParameters',
+        value: { tags: undefined, categories: ['a', 'b'] },
+      },
+      { field: 'stageVariables', value: { env: undefined, version: 'v1' } },
+    ])(
+      'should return true when $field contains undefined values',
+      ({ field, value }) => {
+        const event = { ...baseValidEvent, [field]: value };
+        expect(isAPIGatewayProxyEvent(event)).toBe(true);
+      }
+    );
+
     it.each([
       { case: 'null', event: null },
       { case: 'undefined', event: undefined },
@@ -266,42 +326,52 @@ describe('Path Utilities', () => {
     it.each([
       { field: 'httpMethod', value: 123 },
       { field: 'httpMethod', value: null },
+      { field: 'httpMethod', value: undefined },
       { field: 'path', value: 123 },
       { field: 'path', value: null },
+      { field: 'path', value: undefined },
       { field: 'resource', value: 123 },
       { field: 'resource', value: null },
+      { field: 'resource', value: undefined },
       { field: 'headers', value: 'not an object' },
-      { field: 'headers', value: null },
+      { field: 'headers', value: 123 },
+      { field: 'multiValueHeaders', value: 'not an object' },
+      { field: 'multiValueHeaders', value: 123 },
+      { field: 'queryStringParameters', value: 'not an object' },
+      { field: 'queryStringParameters', value: 123 },
+      { field: 'multiValueQueryStringParameters', value: 'not an object' },
+      { field: 'multiValueQueryStringParameters', value: 123 },
+      { field: 'pathParameters', value: 'not an object' },
+      { field: 'pathParameters', value: 123 },
+      { field: 'stageVariables', value: 'not an object' },
+      { field: 'stageVariables', value: 123 },
       { field: 'requestContext', value: 'not an object' },
       { field: 'requestContext', value: null },
+      { field: 'requestContext', value: undefined },
+      { field: 'requestContext', value: 123 },
       { field: 'isBase64Encoded', value: 'not a boolean' },
       { field: 'isBase64Encoded', value: null },
+      { field: 'isBase64Encoded', value: undefined },
+      { field: 'isBase64Encoded', value: 123 },
       { field: 'body', value: 123 },
+      { field: 'body', value: {} },
     ])(
       'should return false when $field is invalid ($value)',
       ({ field, value }) => {
-        const baseEvent = {
-          httpMethod: 'GET',
-          path: '/test',
-          resource: '/test',
-          headers: {},
-          requestContext: {},
-          isBase64Encoded: false,
-          body: null,
-        };
-
-        const invalidEvent = { ...baseEvent, [field]: value };
+        const invalidEvent = { ...baseValidEvent, [field]: value };
         expect(isAPIGatewayProxyEvent(invalidEvent)).toBe(false);
       }
     );
 
-    it('should return false when required fields are missing', () => {
-      const incompleteEvent = {
-        httpMethod: 'GET',
-        path: '/test',
-        // missing resource, headers, requestContext, isBase64Encoded, body
-      };
-
+    it.each([
+      'httpMethod',
+      'path',
+      'resource',
+      'requestContext',
+      'isBase64Encoded',
+    ])('should return false when required field %s is missing', (field) => {
+      const incompleteEvent = { ...baseValidEvent };
+      delete incompleteEvent[field as keyof typeof incompleteEvent];
       expect(isAPIGatewayProxyEvent(incompleteEvent)).toBe(false);
     });
   });