Merge pull request #40 from apollo-server-integrations/feature/accept-alb-event-type

Added support for ALB event type

Author: BlenderDude

.changeset/blue-baboons-attend.md

@@ -0,0 +1,5 @@
+---
+'@as-integrations/aws-lambda': minor
+---
+
+ALB Event type integration

src/__tests__/integrationALB.test.ts

@@ -0,0 +1,51 @@
+import { ApolloServer, ApolloServerOptions, BaseContext } from '@apollo/server';
+import {
+  CreateServerForIntegrationTestsOptions,
+  defineIntegrationTestSuite,
+} from '@apollo/server-integration-testsuite';
+import type { ALBEvent, ALBResult, Handler } from 'aws-lambda';
+import { createServer } from 'http';
+import { startServerAndCreateLambdaHandler } from '..';
+import { createMockALBServer } from './mockALBServer';
+import { urlForHttpServer } from './mockServer';
+
+describe('lambdaHandlerALB', () => {
+  defineIntegrationTestSuite(
+    async function (
+      serverOptions: ApolloServerOptions<BaseContext>,
+      testOptions?: CreateServerForIntegrationTestsOptions,
+    ) {
+      const httpServer = createServer();
+      const server = new ApolloServer({
+        ...serverOptions,
+      });
+
+      const handler = testOptions
+        ? startServerAndCreateLambdaHandler(server, testOptions)
+        : startServerAndCreateLambdaHandler(server);
+
+      httpServer.addListener(
+        'request',
+        createMockALBServer(handler as Handler<ALBEvent, ALBResult>),
+      );
+
+      await new Promise<void>((resolve) => {
+        httpServer.listen({ port: 0 }, resolve);
+      });
+
+      return {
+        server,
+        url: urlForHttpServer(httpServer),
+        async extraCleanup() {
+          await new Promise<void>((resolve) => {
+            httpServer.close(() => resolve());
+          });
+        },
+      };
+    },
+    {
+      serverIsStartedInBackground: true,
+      noIncrementalDelivery: true,
+    },
+  );
+});

src/__tests__/mockALBServer.ts

@@ -0,0 +1,46 @@
+import url from 'url';
+import type { IncomingMessage } from 'http';
+import type { ALBEvent, ALBResult, Handler } from 'aws-lambda';
+import { createMockServer } from './mockServer';
+
+export function createMockALBServer(handler: Handler<ALBEvent, ALBResult>) {
+  return createMockServer(handler, albEventFromRequest);
+}
+
+function albEventFromRequest(req: IncomingMessage, body: string): ALBEvent {
+  const urlObject = url.parse(req.url || '', false);
+  const searchParams = new URLSearchParams(urlObject.search ?? '');
+
+  const multiValueQueryStringParameters: ALBEvent['multiValueQueryStringParameters'] =
+    {};
+
+  for (const [key] of searchParams.entries()) {
+    const all = searchParams.getAll(key);
+    if (all.length > 1) {
+      multiValueQueryStringParameters[key] = all;
+    }
+  }
+
+  return {
+    requestContext: {
+      elb: {
+        targetGroupArn: '...',
+      },
+    },
+    httpMethod: req.method ?? 'GET',
+    path: urlObject.pathname ?? '/',
+    queryStringParameters: Object.fromEntries(searchParams.entries()),
+    headers: Object.fromEntries(
+      Object.entries(req.headers).map(([name, value]) => {
+        if (Array.isArray(value)) {
+          return [name, value.join(',')];
+        } else {
+          return [name, value];
+        }
+      }),
+    ),
+    multiValueQueryStringParameters,
+    body,
+    isBase64Encoded: false,
+  };
+}

src/__tests__/mockServer.ts

@@ -1,24 +1,28 @@
 import type { IncomingMessage, Server, ServerResponse } from 'http';
 import type {
+  ALBResult,
   APIGatewayProxyEvent,
+  APIGatewayProxyEventV2,
   APIGatewayProxyResult,
   APIGatewayProxyStructuredResultV2,
   Context as LambdaContext,
   Handler,
 } from 'aws-lambda';
 import { format } from 'url';
 import type { AddressInfo } from 'net';
-import type { GatewayEvent } from '..';
+import type { IncomingEvent } from '..';
 
-type LambdaHandler<T = GatewayEvent> = Handler<
+type LambdaHandler<T = IncomingEvent> = Handler<
   T,
   T extends APIGatewayProxyEvent
     ? APIGatewayProxyResult
-    : APIGatewayProxyStructuredResultV2
+    : T extends APIGatewayProxyEventV2
+    ? APIGatewayProxyStructuredResultV2
+    : ALBResult
 >;
 
 // Returns a Node http handler that invokes a Lambda handler (v1 / v2)
-export function createMockServer<T extends GatewayEvent>(
+export function createMockServer<T extends IncomingEvent>(
   handler: LambdaHandler<T>,
   eventFromRequest: (req: IncomingMessage, body: string) => T,
 ) {

src/index.ts

@@ -7,31 +7,41 @@ import type {
 import { HeaderMap } from '@apollo/server';
 import type { WithRequired } from '@apollo/utils.withrequired';
 import type {
+  ALBEvent,
+  ALBResult,
   APIGatewayProxyEvent,
-  APIGatewayProxyEventHeaders,
-  APIGatewayProxyEventQueryStringParameters,
   APIGatewayProxyEventV2,
   APIGatewayProxyResult,
   APIGatewayProxyStructuredResultV2,
   Context,
   Handler,
 } from 'aws-lambda';
 
-export type GatewayEvent = APIGatewayProxyEvent | APIGatewayProxyEventV2;
+export type IncomingEvent =
+  | APIGatewayProxyEvent
+  | APIGatewayProxyEventV2
+  | ALBEvent;
+
+/**
+ * @deprecated Use {IncomingEvent} instead
+ */
+export type GatewayEvent = IncomingEvent;
 
 export interface LambdaContextFunctionArgument {
-  event: GatewayEvent;
+  event: IncomingEvent;
   context: Context;
 }
 
 export interface LambdaHandlerOptions<TContext extends BaseContext> {
   context?: ContextFunction<[LambdaContextFunctionArgument], TContext>;
 }
 
-type LambdaHandler = Handler<
-  GatewayEvent,
-  APIGatewayProxyStructuredResultV2 | APIGatewayProxyResult
->;
+export type HandlerResult =
+  | APIGatewayProxyStructuredResultV2
+  | APIGatewayProxyResult
+  | ALBResult;
+
+type LambdaHandler = Handler<IncomingEvent, HandlerResult>;
 
 export function startServerAndCreateLambdaHandler(
   server: ApolloServer<BaseContext>,
@@ -62,7 +72,7 @@ export function startServerAndCreateLambdaHandler<TContext extends BaseContext>(
 
   return async function (event, context) {
     try {
-      const normalizedEvent = normalizeGatewayEvent(event);
+      const normalizedEvent = normalizeIncomingEvent(event);
 
       const { body, headers, status } = await server.executeHTTPGraphQLRequest({
         httpGraphQLRequest: normalizedEvent,
@@ -90,63 +100,33 @@ export function startServerAndCreateLambdaHandler<TContext extends BaseContext>(
   };
 }
 
-function normalizeGatewayEvent(event: GatewayEvent): HTTPGraphQLRequest {
-  if (isV1Event(event)) {
-    return normalizeV1Event(event);
-  }
-
-  if (isV2Event(event)) {
-    return normalizeV2Event(event);
+function normalizeIncomingEvent(event: IncomingEvent): HTTPGraphQLRequest {
+  let httpMethod: string;
+  if ('httpMethod' in event) {
+    httpMethod = event.httpMethod;
+  } else {
+    httpMethod = event.requestContext.http.method;
   }
-
-  throw Error('Unknown event type');
-}
-
-function isV1Event(event: GatewayEvent): event is APIGatewayProxyEvent {
-  // APIGatewayProxyEvent incorrectly omits `version` even though API Gateway v1
-  // events may include `version: "1.0"`
-  return (
-    !('version' in event) || ('version' in event && event.version === '1.0')
-  );
-}
-
-function isV2Event(event: GatewayEvent): event is APIGatewayProxyEventV2 {
-  return 'version' in event && event.version === '2.0';
-}
-
-function normalizeV1Event(event: APIGatewayProxyEvent): HTTPGraphQLRequest {
   const headers = normalizeHeaders(event.headers);
-  const body = parseBody(event.body, headers.get('content-type'));
-  // Single value parameters can be directly added
-  const searchParams = new URLSearchParams(
-    normalizeQueryStringParams(event.queryStringParameters),
-  );
-  // Passing a key with an array entry to the constructor yields
-  // one value in the querystring with %2C as the array was flattened to a string
-  // Multi values must be appended individually to get the to-spec output
-  for (const [key, values] of Object.entries(
-    event.multiValueQueryStringParameters ?? {},
-  )) {
-    for (const value of values ?? []) {
-      searchParams.append(key, value);
-    }
+  let search: string;
+  if ('rawQueryString' in event) {
+    search = event.rawQueryString;
+  } else if ('queryStringParameters' in event) {
+    search = normalizeQueryStringParams(
+      event.queryStringParameters,
+      event.multiValueQueryStringParameters,
+    ).toString();
+  } else {
+    throw new Error('Search params not parsable from event');
   }
 
-  return {
-    method: event.httpMethod,
-    headers,
-    search: searchParams.toString(),
-    body,
-  };
-}
+  const body = event.body ?? '';
 
-function normalizeV2Event(event: APIGatewayProxyEventV2): HTTPGraphQLRequest {
-  const headers = normalizeHeaders(event.headers);
   return {
-    method: event.requestContext.http.method,
+    method: httpMethod,
     headers,
-    search: event.rawQueryString,
-    body: parseBody(event.body, headers.get('content-type')),
+    search,
+    body: parseBody(body, headers.get('content-type')),
   };
 }
 
@@ -165,20 +145,31 @@ function parseBody(
   return '';
 }
 
-function normalizeHeaders(headers: APIGatewayProxyEventHeaders): HeaderMap {
+function normalizeHeaders(headers: IncomingEvent['headers']): HeaderMap {
   const headerMap = new HeaderMap();
-  for (const [key, value] of Object.entries(headers)) {
+  for (const [key, value] of Object.entries(headers ?? {})) {
     headerMap.set(key, value ?? '');
   }
   return headerMap;
 }
 
 function normalizeQueryStringParams(
-  queryStringParams: APIGatewayProxyEventQueryStringParameters | null,
-): Record<string, string> {
-  const queryStringRecord: Record<string, string> = {};
+  queryStringParams: Record<string, string | undefined> | null | undefined,
+  multiValueQueryStringParameters:
+    | Record<string, string[] | undefined>
+    | null
+    | undefined,
+): URLSearchParams {
+  const params = new URLSearchParams();
   for (const [key, value] of Object.entries(queryStringParams ?? {})) {
-    queryStringRecord[key] = value ?? '';
+    params.append(key, value ?? '');
+  }
+  for (const [key, value] of Object.entries(
+    multiValueQueryStringParameters ?? {},
+  )) {
+    for (const v of value ?? []) {
+      params.append(key, v);
+    }
   }
-  return queryStringRecord;
+  return params;
 }