conversion to TypeScript

Functional change: multi-value request headers and query parameters are not supported - in these cases the first value is returned

Author: mredele

.gitignore

@@ -59,3 +59,6 @@ typings/
 
 # next.js build output
 .next
+
+# dist
+dist

.prettierrc

@@ -0,0 +1,10 @@
+{
+  "printWidth": 100,
+  "semi": false,
+  "singleQuote": true,
+  "tabWidth": 2,
+  "jsxBracketSameLine": true,
+  "htmlWhitespaceSensitivity": "ignore",
+  "trailingComma": "none",
+  "arrowParens": "avoid"
+}

jest.config.js

@@ -0,0 +1,5 @@
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+  roots: ['src']
+}

package-lock.json

@@ -2,8 +2,14 @@
   "name": "lambda-expressless",
   "version": "0.0.0-development",
   "description": "Wrap AWS Lambda functions with Express-like functions to simplify your code",
-  "main": "src/lambda-wrapper.js",
+  "source": "src/lambda-wrapper.ts",
+  "main": "dist/lambda-wrapper.js",
+  "types": "dist/lambda-wrapper.d.ts",
   "scripts": {
+    "prepare": "npm run build",
+    "build": "tsc",
+    "format": "prettier --write \"src/**/*.ts\" \"src/**/*.js\"",
+    "lint": "tslint -p tsconfig.json",
     "test": "jest",
     "coverage": "jest --coverage",
     "travis-deploy-once": "travis-deploy-once",
@@ -21,12 +27,21 @@
   "homepage": "https://github.com/muratcorlu/lambda-expressless#readme",
   "devDependencies": {
     "body-parser": "^1.19.0",
-    "jest": "^24.9.0",
+    "jest": "^26.0.0",
+    "prettier": "^2.1.2",
     "router": "^1.3.3",
-    "semantic-release": "^15.13.21"
+    "semantic-release": "^15.13.21",
+    "ts-jest": "^26.4.3",
+    "@types/jest": "22.2.3",
+    "tslint": "^6.1.3",
+    "tslint-config-prettier": "^1.18.0",
+    "typescript": "^4.0.3"
   },
   "dependencies": {
+    "@types/node": "^14.11.2",
     "@types/aws-lambda": "^8.10.33",
+    "@types/accepts": "1.3.5",
+    "@types/type-is": "1.6.2",
     "accepts": "^1.3.7",
     "type-is": "^1.6.18"
   }

package.json

@@ -0,0 +1,60 @@
+import { Request } from './request'
+import { Response } from './response'
+import { APIGatewayProxyHandler, APIGatewayProxyResult } from 'aws-lambda'
+
+export interface Middleware {
+  (request: Request, response: Response, next: (param?: unknown) => void): void
+}
+
+export interface OnFinishedHandler {
+  (out: unknown, req: Request, res: Response): Promise<APIGatewayProxyResult>
+}
+
+/**
+ * API Gateway handler generator for Lambda
+ *
+ * @param router Express compatible router instance
+ * @param onFinished Last callback before output gets send. Function params: out, req, res
+ * @return Lambda handler for API gateway events
+ * @public
+ */
+
+exports.ApiGatewayHandler = (router: Middleware, onFinished: OnFinishedHandler) => {
+  /**
+   * Lambda Handler for API Gateway invocations
+   *
+   * @param {object} event API Gateway event object
+   * @param {object} context API Gateway context object
+   * @return {promise} Returns undefined if callback param is set. Return a promise if callback param is undefined.
+   */
+  const handleApiGatewayEvent: APIGatewayProxyHandler = function (event, context) {
+    return new Promise(resolve => {
+      const req = new Request(event)
+      const res = (req.res = new Response(req, async (err, out) => {
+        if (err) {
+          console.error(err)
+        }
+        // run and wait for onFinished callback
+        if (onFinished)
+          try {
+            out = await onFinished(err || out, req, res)
+          } catch (err) {
+            console.error('Error in onFinished callback: ', err)
+          }
+        // resolve promise even if onFinished callback errors out
+        resolve(out)
+      }))
+      router(req, res, err => {
+        // handle generic routing errors
+        // use error handling middleware for more granular control
+        if (err) {
+          console.error('ERROR: ', err)
+          res.status(500).send('Server error')
+        } else {
+          res.status(404).send('Not found')
+        }
+      })
+    })
+  }
+  return handleApiGatewayEvent
+}