Use aws-lambda types and multi value headers

Author: blakeembrey

package-lock.json

@@ -79,7 +79,7 @@
     "servie": "^3.0.0"
   },
   "dependencies": {
-    "bit-string-mask": "^1.0.0",
+    "@types/aws-lambda": "^8.10.23",
     "servie-errorhandler": "^1.2.0",
     "servie-finalhandler": "^1.1.0",
     "servie-http": "^1.1.0"

package.json

@@ -9,20 +9,26 @@ describe("servie-lambda", () => {
     httpMethod: "GET",
     body: null,
     resource: "/test",
-    headers: null,
-    queryStringParameters: null,
+    headers: {},
+    multiValueHeaders: {
+      Test: ["a", "b", "c"]
+    },
+    isBase64Encoded: false,
+    queryStringParameters: {},
+    multiValueQueryStringParameters: {},
+    stageVariables: {},
     requestContext: {
       identity: {
-        sourceIp: ""
+        sourceIp: "127.0.0.1"
       }
-    }
+    } as any
   };
 
-  const context = {
+  const context = ({
     functionName: "",
     functionVersion: "$LATEST",
     memoryLimitInMB: "128"
-  } as Context;
+  } as any) as Context;
 
   it("should support routers", done => {
     const handler = createHandler(function() {
@@ -34,17 +40,15 @@ describe("servie-lambda", () => {
       );
     });
 
-    return handler(event, context, (err: Error | null, res: Result) => {
-      if (err) {
-        return done(err);
-      }
+    return handler(event, context, (err, res) => {
+      if (err) return done(err);
 
       expect(res).toEqual({
         statusCode: 200,
         body: "response",
-        headers: {
-          "content-type": "text/plain",
-          "content-length": "8"
+        multiValueHeaders: {
+          "Content-Type": ["text/plain"],
+          "Content-Length": ["8"]
         },
         isBase64Encoded: false
       });
@@ -56,19 +60,17 @@ describe("servie-lambda", () => {
   it("should fall through to 404", done => {
     const handler = createHandler((_req, next) => next());
 
-    return handler(event, context, (err: Error | null, res: Result) => {
-      if (err) {
-        return done(err);
-      }
+    return handler(event, context, (err, res) => {
+      if (err) return done(err);
 
       expect(res).toEqual({
         statusCode: 404,
         body: "Cannot GET /test",
-        headers: {
-          "content-type": "text/plain",
-          "content-security-policy": "default-src 'self'",
-          "x-content-type-options": "nosniff",
-          "content-length": "16"
+        multiValueHeaders: {
+          "Content-Type": ["text/plain"],
+          "Content-Security-Policy": ["default-src 'self'"],
+          "X-Content-Type-Options": ["nosniff"],
+          "Content-Length": ["16"]
         },
         isBase64Encoded: false
       });
@@ -86,18 +88,14 @@ describe("servie-lambda", () => {
       });
     });
 
-    return handler(event, context, (err: Error | null, res: Result) => {
-      if (err) {
-        return done(err);
-      }
+    return handler(event, context, (err, res) => {
+      if (err) return done(err);
 
       expect(res).toEqual({
         statusCode: 200,
         body: "",
-        headers: {
-          "set-cookie": "a=a",
-          "Set-cookie": "b=b",
-          "sEt-cookie": "c=c"
+        multiValueHeaders: {
+          "Set-Cookie": ["a=a", "b=b", "c=c"]
         },
         isBase64Encoded: false
       });
@@ -112,14 +110,12 @@ describe("servie-lambda", () => {
       logError
     });
 
-    return handler(event, context, (err: Error | null, res: Result) => {
-      if (err) {
-        return done(err);
-      }
+    return handler(event, context, (err, res) => {
+      if (err) return done(err);
 
-      expect(res.statusCode).toEqual(500);
-      expect(res.isBase64Encoded).toEqual(false);
-      expect(res.body).toContain("boom");
+      expect(res!.statusCode).toEqual(500);
+      expect(res!.isBase64Encoded).toEqual(false);
+      expect(res!.body).toContain("boom");
       expect(logError).toHaveBeenCalled();
 
       return done();

src/index.spec.ts

@@ -4,79 +4,14 @@ import { HttpRequest, HttpRequestOptions } from "servie-http";
 import { createBody } from "servie/dist/body/node";
 import { errorhandler } from "servie-errorhandler";
 import { finalhandler } from "servie-finalhandler";
-import { mask } from "bit-string-mask";
+import {
+  APIGatewayEvent as Event,
+  APIGatewayProxyHandler as Handler,
+  APIGatewayProxyResult as Result,
+  Context
+} from "aws-lambda";
 
-/**
- * AWS Lambda event object.
- */
-export interface Event {
-  path: string;
-  httpMethod: string;
-  body: string | null;
-  isBase64Encoded?: boolean;
-  resource: string;
-  headers: {
-    [key: string]: string;
-  } | null;
-  queryStringParameters: {
-    [key: string]: string;
-  } | null;
-  pathParameters: {
-    [key: string]: string;
-  } | null;
-  requestContext: {
-    identity: {
-      sourceIp: string;
-    };
-  };
-}
-
-/**
- * AWS lambda context object.
- *
- * Reference: https://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-context.html
- */
-export interface Context {
-  getRemainingTimeInMillis: () => number;
-  callbackWaitsForEmptyEventLoop: boolean;
-  functionName: string;
-  functionVersion: string;
-  invokedFunctionArn: string;
-  memoryLimitInMB: string;
-  awsRequestId: string;
-  logGroupName: string;
-  logStreamName: string;
-  identity: { cognitoIdentityId: string; cognitoIdentityPoolId: string } | null;
-  clientContext: {
-    client: {
-      installation_id: string;
-      app_title: string;
-      app_version_name: string;
-      app_version_code: string;
-      app_package_name: string;
-    };
-    Custom: any;
-    env: {
-      platform_version: string;
-      platform: string;
-      make: string;
-      model: string;
-      locale: string;
-    };
-  } | null;
-}
-
-/**
- * Standard lambda HTTP response.
- */
-export interface Result {
-  body?: string;
-  statusCode?: number;
-  headers?: {
-    [key: string]: string | string[];
-  };
-  isBase64Encoded?: boolean;
-}
+export { Handler, Event, Context, Result };
 
 /**
  * Extends HTTP requests with AWS lambda context.
@@ -117,19 +52,15 @@ export interface Options {
 /**
  * Create a server for handling AWS Lambda requests.
  */
-export function createHandler(app: App, options: Options = {}) {
-  return function(
-    event: Event,
-    context: Context,
-    cb: (err: Error | null, res: Result) => void
-  ): void {
+export function createHandler(app: App, options: Options = {}): Handler {
+  return function(event, context, callback): void {
     const { httpMethod: method } = event;
     const url = format({
       pathname: event.path,
-      query: event.queryStringParameters
+      query: event.multiValueQueryStringParameters
     });
     const isBinary = options.isBinary || (() => false);
-    const headers = createHeaders(event.headers);
+    const headers = createHeaders(event.multiValueHeaders);
     const rawBody = event.body
       ? Buffer.from(event.body, event.isBase64Encoded ? "base64" : "utf8")
       : undefined;
@@ -165,7 +96,7 @@ export function createHandler(app: App, options: Options = {}) {
         .arrayBuffer()
         .then(buffer => {
           const { statusCode } = res;
-          const headers = toHeaders(res.allHeaders);
+          const multiValueHeaders = toMultiValueHeaders(res.allHeaders);
           const isBase64Encoded = isBinary(res);
           const body = Buffer.from(buffer).toString(
             isBase64Encoded ? "base64" : "utf8"
@@ -177,7 +108,12 @@ export function createHandler(app: App, options: Options = {}) {
           res.finished = true;
           res.bytesTransferred = buffer ? buffer.byteLength : 0;
 
-          return cb(null, { statusCode, headers, body, isBase64Encoded });
+          return callback(null, {
+            statusCode,
+            multiValueHeaders,
+            body,
+            isBase64Encoded
+          });
         })
         .catch(err => sendResponse(mapError(err)));
     }
@@ -203,21 +139,8 @@ export function createHandler(app: App, options: Options = {}) {
 /**
  * Return a lambda compatible object of headers.
  */
-function toHeaders(headers: Headers) {
-  const result = Object.create(null);
-  const obj = headers.asObject();
-
-  for (const key of Object.keys(obj)) {
-    const val = obj[key];
-
-    if (Array.isArray(val)) {
-      for (let i = 0; i < val.length; i++) {
-        result[mask(key, i)] = val[i];
-      }
-    } else {
-      result[key] = val;
-    }
-  }
-
+function toMultiValueHeaders(headers: Headers) {
+  const result: NonNullable<Result["multiValueHeaders"]> = Object.create(null);
+  for (const key of headers.keys()) result[key] = headers.getAll(key);
   return result;
 }