migrate to typescript (spring-media#29)

* add typescript + tests and dist/js for comparison
* remove old javascript implementation

Author: tdt17

.editorconfig

@@ -0,0 +1,17 @@
+# EditorConfig helps developers define and maintain consistent
+# coding styles between different editors and IDEs
+# editorconfig.org
+
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+trim_trailing_whitespace = false

.gitignore

@@ -1,3 +1,4 @@
 node_modules
 .idea
 *.iml
+dist

.travis.yml

@@ -1,5 +1,4 @@
 language: node_js
 
-# test on two node.js versions: 0.6 and 0.8
 node_js:
-  - 6
+  - 8

README.md

@@ -36,10 +36,9 @@ $ yarn add aws-lambda-router
 This is a simple example of `aws-lambda-router` in conjunction with ANY method and the API Gateway proxy integration. The following code will respond with a message when executed using an AWS API Gateway with a `GET` request on URL path `<base-url-of-gateway>/gateway-mapping/article/123`.
 
 ```js
-const router = require('aws-lambda-router');
+import * as router from 'aws-lambda-router'
 
-// handler for an api gateway event
-exports.handler = router.handler({
+export const handler = router.handler({
     // for handling an http-call from an AWS API Gateway proxyIntegration we provide the following config:
     proxyIntegration: {
         routes: [
@@ -66,9 +65,9 @@ See the following example:
 
 
 ```js
-const router = require('aws-lambda-router');
+import * as router from 'aws-lambda-router'
 
-exports.handler = router.handler({
+export const handler = router.handler({
     // for handling an http-call from an AWS Apigateway proxyIntegration we provide the following config:
     proxyIntegration: {
         cors: true,
@@ -94,9 +93,9 @@ If CORS is activated, these default headers will be sent on every response:
 ## Errormapping
 
 ```js
-const router = require('aws-lambda-router');
+import * as router from 'aws-lambda-router'
 
-exports.handler = router.handler({
+export const handler = router.handler({
     // for handling an http-call from an AWS Apigateway proxyIntegration we provide the following config:
     proxyIntegration: {
         routes: [
@@ -135,9 +134,9 @@ SNS Event Structure: https://docs.aws.amazon.com/sns/latest/dg/sns-message-and-j
 For handling calls in Lambdas initiated from AWS-SNS you can use the following code snippet:
 
 ```js
-const router = require('aws-lambda-router');
+import * as router from 'aws-lambda-router'
 
-exports.handler = router.handler({
+export const handler = router.handler({
     sns: {
         routes: [
             {
@@ -156,9 +155,9 @@ exports.handler = router.handler({
 For handling calls in Lambdas initiated from AWS-SQS you can use the following code snippet:
 
 ```js
-const router = require('aws-lambda-router');
+import * as router from 'aws-lambda-router'
 
-exports.handler = router.handler({
+export const handler = router.handler({
     sqs: {
         routes: [
             {
@@ -200,9 +199,9 @@ The action method will be called with the records of the [S3Event Structure](htt
 The following examples demonstrates the most use cases:
 
 ```js
-const router = require('aws-lambda-router');
+import * as router from 'aws-lambda-router'
 
-exports.handler = router.handler({
+export const handler = router.handler({
     s3: {
         routes: [
             {
@@ -290,6 +289,7 @@ See here: https://yarnpkg.com/en/docs/cli/link
 
 ## Release History
 
+* 0.7.0 migrate to typescript; using aws-lambda typings; proxyIntegration: cors is now optional (default: false);
 * 0.6.2 take away old gulp dependency to run tests, works now with scripts in package.json; normalize request path to start from local host (thanks to [@napicella](https://github.com/napicella))
 * 0.6.1 s3: fix: aggregate result promises to one promise; fix: s3Route interface
 * 0.6.0 new feature: S3 routes available. 

index.d.ts

@@ -0,0 +1,68 @@
+import { ProxyIntegrationConfig, ProxyIntegrationEvent } from "./lib/proxyIntegration";
+import { SnsConfig, SnsEvent } from "./lib/sns";
+import { SqsConfig, SqsEvent } from "./lib/sqs";
+import { S3Config, S3Event } from "./lib/s3";
+import { Context } from "aws-lambda";
+import { EventProcessor } from "./lib/EventProcessor";
+
+export interface RouteConfig {
+  proxyIntegration?: ProxyIntegrationConfig
+  sns?: SnsConfig
+  sqs?: SqsConfig
+  s3?: S3Config
+  debug?: boolean
+}
+
+export type RouterEvent = ProxyIntegrationEvent | SnsEvent | SqsEvent | S3Event
+
+export const handler = (routeConfig: RouteConfig) => {
+  const eventProcessorMapping = extractEventProcessorMapping(routeConfig);
+
+  return async <TContext extends Context>(event: RouterEvent, context: TContext) => {
+    if (routeConfig.debug) {
+      console.log("Lambda invoked with request:", event);
+      console.log("Lambda invoked with context:", context);
+    }
+
+    for (const [eventProcessorName, eventProcessor] of eventProcessorMapping.entries()) {
+
+      try {
+        // the contract of 'processors' is as follows:
+        // - their method 'process' is called with (config, event)
+        // - the method...
+        //   - returns null: the processor does not feel responsible for the event
+        //   - throws Error: the 'error.toString()' is taken as the error message of processing the event
+        //   - returns object: this is taken as the result of processing the event
+        //   - returns promise: when the promise is resolved, this is taken as the result of processing the event
+        const result = eventProcessor.process((routeConfig as any)[eventProcessorName], event, context);
+        if (result) {
+          // be resilient against a processor returning a value instead of a promise:
+          return await result
+        } else {
+          if (routeConfig.debug) {
+            console.log("Event processor couldn't handle request.")
+          }
+        }
+      } catch (error) {
+        if (error.stack) {
+          console.log(error.stack)
+        }
+        throw error.toString()
+      }
+    }
+    throw 'No event processor found to handle this kind of event!'
+  }
+}
+
+const extractEventProcessorMapping = (routeConfig: RouteConfig) => {
+  const processorMap = new Map<string, EventProcessor>()
+  for (let key of Object.keys(routeConfig)) {
+    if (key === 'debug') continue
+    try {
+      processorMap.set(key, require(`./lib/${key}`))
+    } catch (error) {
+      throw new Error(`The event processor '${key}', that is mentioned in the routerConfig, cannot be instantiated (${error.toString()})`)
+    }
+  }
+  return processorMap;
+}

index.js

@@ -0,0 +1,4 @@
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+};

index.ts

@@ -0,0 +1,6 @@
+export interface EventProcessor<TConfig = any, TEvent = any, TContext = any, TOutput = any> {
+  process: ProcessMethod<TConfig, TEvent, TContext, TOutput>
+}
+
+export type ProcessMethod<TConfig, TEvent, TContext, TOutput = any> =
+  (config: TConfig, event: TEvent, context: TContext) => null | TOutput | Promise<TOutput>