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ofhouseofhouse
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Adds ability to start lambdas without API (#7)
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‎.github/workflows/CI.yml

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name: CI
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on:
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push:
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branches:
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- main
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pull_request:
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test:
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runs-on: ubuntu-latest
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env:
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SAM_CLI_TELEMETRY: 0
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# Don't worry these are fake AWS credentials for AWS SAM
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AWS_ACCESS_KEY_ID: ABIAZLJNBT8I3KFOU4NO
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AWS_SECRET_ACCESS_KEY: 4Xt3Rbx4DO21MhK1IHXZXRvVRDuqaQ0Wo5lILA/h
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steps:
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- name: Setup AWS SAM
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run: |
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brew tap aws/tap
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brew install aws-sam-cli
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sam --version
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- uses: actions/checkout@v2
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- uses: actions/setup-node@v2
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with:
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node-version: '14'
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cache: 'yarn'
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- name: Install dependencies
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run: yarn install --frozen-lockfile --check-files
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- name: Run tests
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run: yarn test --runInBand

‎.prettierignore

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# Build output
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dist

‎README.md

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yarn add -D @dealmore/sammy # or yarn
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```
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Assuming you have a Lambda function with the following content:
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```js
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// handler.js
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exports.handler = async function (event, context) {
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return {
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isBase64Encoded: false,
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statusCode: 200,
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body: 'Hello World!',
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headers: {
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'content-type': 'application/json',
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},
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};
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};
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```
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which is packaged into a compressed zip file called `lambda.zip`.
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### Run lambda locally with API-Gateway
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You can now start the Lambda function locally and access it through an API-Endpoint:
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```ts
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import * as path from 'path';
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import type { APISAMGenerator } from '@dealmore/sammy';
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import { generateAPISAM } from '@dealmore/sammy';
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const lambdaSAM = await generateAPISAM({
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lambdas: {
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first: {
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filename: 'first.zip',
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handler: 'handler.handler',
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runtime: 'nodejs14.x',
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route: '/test',
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method: 'get',
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},
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},
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cwd: process.cwd(),
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});
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const response = await lambdaSAM.sendApiGwRequest('/test');
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console.log(await response.text());
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// => Hello World!
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```
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## License
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Apache-2.0 - see [LICENSE](./LICENSE) for details.

‎jest.config.js

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module.exports = {
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preset: 'ts-jest',
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testEnvironment: 'node',
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rootDir: './',
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};

‎lib/SAMGenerator.ts

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import * as fs from 'fs';
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import { EventEmitter } from 'events';
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import * as path from 'path';
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import getPort from 'get-port';
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import { dirSync as tmpDirSync, DirResult } from 'tmp';
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import { SAMTemplate } from './SAMTemplate';
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import { ConfigLambda, SAMLocalAPICLIOptions } from './types';
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import { unzipToLocation } from './utils';
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import { createSAMLocal, SAMLocal } from './SAMLocal';
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type GeneratorType = 'api' | 'sdk';
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type SAMInstance = {
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port: number;
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host: string;
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endpoint: string;
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region: string;
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};
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class LoggerEmitter extends EventEmitter {}
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/**
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* Generator for an AWS SAM CLI instance
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*/
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class SAMGenerator {
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loggerEmitter: LoggerEmitter;
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SAM?: SAMLocal;
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SAMInstance?: SAMInstance;
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template: SAMTemplate;
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tmpDir: DirResult;
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type: GeneratorType;
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constructor(type: GeneratorType) {
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this.loggerEmitter = new LoggerEmitter();
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this.tmpDir = tmpDirSync({ unsafeCleanup: true });
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this.template = new SAMTemplate();
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this.type = type;
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}
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// Explicit `this` binding
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private onData = (message: any) => {
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this.loggerEmitter.emit('data', message);
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};
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// Explicit `this` binding
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private onError = (message: any) => {
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this.loggerEmitter.emit('error', message);
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};
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/**
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* Unpacks the lambdas into a temporary workDir and creates a SAM Template
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* that can be passed to AWS SAM CLI
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*
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* @param lambdas - Key/Value object with the lambdas that should be created
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* @param cwd
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*/
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async generateLambdas(
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lambdas: Record<string, ConfigLambda>,
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cwd: string = process.cwd()
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) {
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// Unpack all lambdas
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for (const [functionName, lambda] of Object.entries(lambdas)) {
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const functionSourcePath = path.isAbsolute(lambda.filename)
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? lambda.filename
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: path.join(cwd, lambda.filename);
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await unzipToLocation(
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functionSourcePath,
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path.join(this.tmpDir.name, functionName)
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);
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this.template.addLambda(functionName, {
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Type: 'AWS::Serverless::Function',
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Properties: {
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Handler: `${functionName}/${lambda.handler}`,
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Description: functionName,
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Runtime: lambda.runtime,
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MemorySize: lambda.memorySize ?? 128,
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Timeout: 29, // Max timeout from API Gateway
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Environment: {
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Variables: lambda.environment ?? {},
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},
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},
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});
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if (lambda.route) {
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this.template.addRoute(functionName, 'api', {
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Type: 'HttpApi',
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Properties: {
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Path: lambda.route,
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Method: lambda.method ?? 'any',
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TimeoutInMillis: 29000, // Max timeout
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PayloadFormatVersion: '2.0',
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},
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});
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} else if (lambda.routes) {
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for (const routeKey in lambda.routes) {
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this.template.addRoute(functionName, routeKey, {
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Type: 'HttpApi',
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Properties: {
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Path: lambda.routes[routeKey],
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Method: lambda.method ?? 'any',
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TimeoutInMillis: 29000, // Max timeout
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PayloadFormatVersion: '2.0',
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},
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});
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}
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}
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// Write the SAM template
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fs.writeFileSync(
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path.join(this.tmpDir.name, 'template.yml'),
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this.template.toYaml()
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);
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}
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}
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/**
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* Start the AWS SAM CLI
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*
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* @param cliOptions
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*/
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async start(cliOptions: SAMLocalAPICLIOptions = {}) {
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const port = cliOptions.port || (await getPort());
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const host = cliOptions.host || '127.0.0.1';
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const endpoint = `http://${host}:${port}`;
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const region = cliOptions.region || 'local';
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this.SAM = await createSAMLocal(this.type, this.tmpDir.name, {
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onData: this.onData,
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onError: this.onError,
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cliOptions: { ...cliOptions, port, host, region },
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});
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this.SAMInstance = {
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port,
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host,
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endpoint,
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region,
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};
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return this.SAMInstance;
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}
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/**
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* Stop the AWS SAM CLI
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*/
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async stop() {
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if (this.SAM) {
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await this.SAM.kill();
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}
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this.tmpDir.removeCallback();
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this.SAMInstance = undefined;
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}
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/**
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* Subscribe to data or error messages from the CLI
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* @param topic
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* @param callback
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*/
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on(topic: 'data' | 'error', callback: (data: string) => void) {
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this.loggerEmitter.on(topic, callback);
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}
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/**
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* Unsubscribe to data or error messages from the CLI
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* @param topic
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* @param callback
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*/
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off(topic: 'data' | 'error', callback: (data: string) => void) {
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this.loggerEmitter.off(topic, callback);
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}
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}
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export { SAMGenerator };

‎lib/SAMTemplate.ts

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import { stringify as yaml } from 'yaml';
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import {
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SAMTemplate as SAMTemplateJSON,
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ServerLessFunction,
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ServerLessFunctionAPIEvent,
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} from './types';
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type PickPartial<T, K extends keyof T> = { [P in K]: Partial<T[P]> };
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type PartialServerLessFunctionProps = 'MemorySize' | 'Runtime' | 'Timeout';
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type ServerLessFunctionArgs = ServerLessFunction & {
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Properties: PickPartial<
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ServerLessFunction['Properties'],
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PartialServerLessFunctionProps
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>;
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};
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const defaultFunctionProperties: Pick<
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ServerLessFunction['Properties'],
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PartialServerLessFunctionProps
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> = {
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MemorySize: 128, // in mb
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Runtime: 'nodejs14.x',
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Timeout: 30, // in seconds
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};
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/**
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* Helper class to generate the SAMTemplate
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*/
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class SAMTemplate {
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template: SAMTemplateJSON;
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constructor() {
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// Default header
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this.template = {
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AWSTemplateFormatVersion: '2010-09-09',
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Transform: ['AWS::Serverless-2016-10-31'],
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Resources: {},
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};
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}
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private addAPIGatewayOutput() {
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if (!this.template.Outputs) {
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this.template.Outputs = {};
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}
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if (!('WebEndpoint' in this.template.Outputs)) {
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this.template.Outputs['WebEndpoint'] = {
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Value:
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"!Sub 'https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/'",
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};
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}
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}
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addLambda(functionName: string, lambda: ServerLessFunctionArgs) {
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this.template.Resources[functionName] = {
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...lambda,
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Properties: {
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...defaultFunctionProperties,
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...lambda.Properties,
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},
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};
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}
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addRoute(
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functionName: string,
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routeKey: string,
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apiEvent: ServerLessFunctionAPIEvent
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) {
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if (!(functionName in this.template.Resources)) {
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throw new Error(
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`No function resource with name "${functionName}". Please create the function first before adding routes.`
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);
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}
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// Initialize Events if not present
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if (!this.template.Resources[functionName].Properties.Events) {
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this.template.Resources[functionName].Properties.Events = {};
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}
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this.template.Resources[functionName].Properties.Events![
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routeKey
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] = apiEvent;
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this.addAPIGatewayOutput();
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}
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toYaml() {
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return yaml(this.template);
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}
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}
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export { SAMTemplate };

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