@types/aws-lambda: There are no types for the communication with Application Load Balancer (#33763)

* Add the additional types for the usage of Application Load Balancer

* Change the long name "Application Load Balancer" to shorter one "ALB"

* Add ALBCallback for the completeness of the communication with the ALB

types/aws-lambda/aws-lambda-tests.ts

@@ -8,10 +8,14 @@ declare let num: number;
 declare let error: Error;
 declare let bool: boolean;
 declare let boolOrUndefined: boolean | undefined;
+declare let boolOrNumOrStr: boolean | number | string;
 declare let numOrUndefined: number | undefined;
 declare let apiGwEvtReqCtx: AWSLambda.APIGatewayEventRequestContext;
 declare let apiGwEvtReqCtxOpt: AWSLambda.APIGatewayEventRequestContext | null | undefined;
 declare let apiGwEvt: AWSLambda.APIGatewayEvent;
+declare let albEvtReqCtx: AWSLambda.ALBEventRequestContext;
+declare let albEvt: AWSLambda.ALBEvent;
+declare let albRes: AWSLambda.ALBResult;
 declare let customAuthorizerEvt: AWSLambda.CustomAuthorizerEvent;
 declare let clientCtx: AWSLambda.ClientContext;
 declare let clientCtxOrUndefined: AWSLambda.ClientContext | undefined;
@@ -125,6 +129,27 @@ str = apiGwEvt.stageVariables!["example"];
 apiGwEvtReqCtx = apiGwEvt.requestContext;
 str = apiGwEvt.resource;
 
+/* Application Load Balancer Event Request Context */
+str = albEvtReqCtx.elb.targetGroupArn;
+
+/* Application Load Balancer Event */
+str = albEvt.httpMethod;
+str = albEvt.path;
+str = albEvt.queryStringParameters!["example"];
+str = albEvt.headers!["example"];
+str = albEvt.multiValueQueryStringParameters!["example"][0];
+str = albEvt.multiValueHeaders!["example"][0];
+strOrNull = albEvt.body;
+bool = albEvt.isBase64Encoded;
+
+/* Application Load Balancer Result */
+num = albRes.statusCode;
+str = albRes.statusDescription;
+boolOrNumOrStr = albRes.headers!["example"];
+boolOrNumOrStr = albRes.multiValueHeaders!["example"][0];
+str = albRes.body;
+bool = albRes.isBase64Encoded;
+
 /* API Gateway CustomAuthorizer Event */
 str = customAuthorizerEvt.type;
 str = customAuthorizerEvt.methodArn;
@@ -879,6 +904,33 @@ const inferredHandler: AWSLambda.S3Handler = (event, context, cb) => {
 // Test using default Callback type still works.
 const defaultCallbackHandler: AWSLambda.APIGatewayProxyHandler = (event: AWSLambda.APIGatewayEvent, context: AWSLambda.Context, cb: AWSLambda.Callback) => { };
 
+const albSyncHandler: AWSLambda.ALBHandler = (
+    event: AWSLambda.ALBEvent,
+    context: AWSLambda.Context,
+    cb: AWSLambda.ALBCallback,
+) => {
+    cb(null, {
+        statusCode: 200,
+        statusDescription: '200 OK',
+        headers: { },
+        body: '',
+        isBase64Encoded: false,
+    });
+};
+const albAsyncHandler: AWSLambda.ALBHandler = async (
+    event: AWSLambda.ALBEvent,
+    context: AWSLambda.Context,
+    cb: AWSLambda.ALBCallback,
+) => {
+    return {
+        statusCode: 200,
+        statusDescription: '200 OK',
+        headers: { },
+        body: '',
+        isBase64Encoded: false,
+    };
+};
+
 // Specific types
 let s3Handler: AWSLambda.S3Handler = (event: AWSLambda.S3Event, context: AWSLambda.Context, cb: AWSLambda.Callback<void>) => {};
 // Test old name

types/aws-lambda/index.d.ts

@@ -28,6 +28,7 @@
 //                 Loïk Gaonac'h <https://github.com/loikg>
 //                 Roberto Zen <https://github.com/skyzenr>
 //                 Richard Cornelissen <https://github.com/richardcornelissen>
+//                 Grzegorz Redlicki <https://github.com/redlickigrzegorz>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.3
 
@@ -86,6 +87,24 @@ export interface APIGatewayProxyEvent {
 }
 export type APIGatewayEvent = APIGatewayProxyEvent; // Old name
 
+// https://docs.aws.amazon.com/elasticloadbalancing/latest/application/lambda-functions.html
+export interface ALBEventRequestContext {
+    elb: {
+        targetGroupArn: string;
+    };
+}
+export interface ALBEvent {
+    requestContext: ALBEventRequestContext;
+    httpMethod: string;
+    path: string;
+    queryStringParameters?: { [parameter: string]: string }; // URL encoded
+    headers?: { [header: string]: string };
+    multiValueQueryStringParameters?: { [parameter: string]: string[] }; // URL encoded
+    multiValueHeaders?: { [header: string]: string[] };
+    body: string | null;
+    isBase64Encoded: boolean;
+}
+
 // API Gateway CustomAuthorizer "event"
 export interface CustomAuthorizerEvent {
     type: string;
@@ -474,6 +493,15 @@ export interface APIGatewayProxyResult {
 }
 export type ProxyResult = APIGatewayProxyResult; // Old name
 
+export interface ALBResult {
+    statusCode: number;
+    statusDescription: string;
+    headers?: { [header: string]: boolean | number | string };
+    multiValueHeaders?: { [header: string]: Array<boolean | number | string> };
+    body: string;
+    isBase64Encoded: boolean;
+}
+
 /**
  * API Gateway CustomAuthorizer AuthResponse.
  * http://docs.aws.amazon.com/apigateway/latest/developerguide/use-custom-authorizer.html#api-gateway-custom-authorizer-output
@@ -1058,6 +1086,9 @@ export type APIGatewayProxyCallback = Callback<APIGatewayProxyResult>;
 export type ProxyHandler = APIGatewayProxyHandler; // Old name
 export type ProxyCallback = APIGatewayProxyCallback; // Old name
 
+export type ALBHandler = Handler<ALBEvent, ALBResult>;
+export type ALBCallback = Callback<ALBResult>;
+
 // TODO: IoT
 
 export type CodePipelineHandler = Handler<CodePipelineEvent, void>;