feat: serverless-offline-lambda-function-urls plugin

Author: MarioSimou

.gitignore

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+node_modules/
+.turbo/

.prettierignore

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+node_modules/
+.turbo/

.prettierrc.cjs

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+module.exports = require('../configuration/prettier.json')

README.md

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+# Serverless Offline - Lambda Function Urls
+
+## Description
+
+This plugin provides a temporal solution to the issue described [here](https://github.com/dherault/serverless-offline/issues/1382).
+
+### Setup
+
+1. Inside your project's `serverless.yml` file, add the following entry in the `plugins` section.
+
+```yaml
+plugins:
+  - serverless-offline
+  - serverless-offline-lambda-function-urls
+```
+
+2. Configure the port where the new server will be running. By default, the server will run on 3003.
+
+```yaml
+serverless-offline:
+  urlLambdaFunctionsHttpPort: 3003
+```
+
+3. Configure a lambda url function. When you add the `url` option, the handler will expose it as a `GET/POST` HTTP endpoint(`/dev/ping`). The HTTP endpoint doesn't go through the API Gateway, which means that you can set your own `timeout` and it will respect it. Traditionally, the API Gateway would timeout after 30 seconds.
+
+```yaml
+ping:
+  handler: ./src/functions/ping.handler
+  url: true
+  timeout: 120 # The handler will timeout after 2 minutes and API Gateway won't interrupt it
+```
+
+4. Run `serverless offline` and the plugin will be triggerred by the `offline:start:init` event.
+
+```bash
+serverless offline start
+```

index.js

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+import {resolve, join} from 'node:path'
+import {cwd} from 'node:process'
+
+export default class ServerlessOfflineLambdaFunctionUrls {
+  constructor(serverless) {
+    const configuration = serverless.config.serverless.configurationInput
+    this.serverless = serverless
+    this.configuration = configuration
+    this.hooks = {
+      'offline:start:init': () => this.init(),
+    }
+  }
+  getLambdas(functions) {
+    return Object.entries(functions).reduce(
+      (lambdas, [functionKey, functionDefinition]) => [
+        ...lambdas,
+        {
+          functionKey,
+          functionDefinition: {
+            ...functionDefinition,
+            handler: this.getTranspiledHandlerFilepath(functionDefinition.handler),
+          },
+        },
+      ],
+      []
+    )
+  }
+  filterNonUrlEnabledFunctions(configuration) {
+    return Object.entries(configuration.functions).reduce((functions, [functionKey, functionDefinition]) => {
+      if (!functionDefinition.url) {
+        return functions
+      }
+      return {...functions, [functionKey]: functionDefinition}
+    }, {})
+  }
+  getEvents(functions) {
+    return Object.entries(functions).reduce((events, [functionKey, {handler}]) => {
+      const path = `/${encodeURIComponent(functionKey)}`
+      return [
+        ...events,
+        {functionKey, handler, http: {path, method: 'GET'}},
+        {functionKey, handler, http: {path, method: 'POST'}},
+      ]
+    }, [])
+  }
+  mergeServerlessOfflineOptions(options) {
+    const stage = this.serverless.variables.options?.stage ?? this.configuration.provider?.stage
+    const serverlessOfflineOptions = this.configuration.custom['serverless-offline']
+    return {
+      ...serverlessOfflineOptions,
+      stage,
+      httpPort: serverlessOfflineOptions['urlLambdaFunctionsHttpPort'] ?? 3003,
+      ...options,
+    }
+  }
+  getTranspiledHandlerFilepath(handler) {
+    return join('.esbuild', '.build', handler)
+  }
+  getFullPath(...args) {
+    return resolve(cwd(), ...args)
+  }
+  async init() {
+    const {default: Lambda} = await import(this.getFullPath('node_modules', 'serverless-offline/src/lambda/Lambda.js'))
+    const {default: Http} = await import(this.getFullPath('node_modules', 'serverless-offline/src/events/http/Http.js'))
+    const functions = this.filterNonUrlEnabledFunctions(this.configuration)
+
+    const lambda = new Lambda(this.serverless, this.mergeServerlessOfflineOptions({noTimeout: true}))
+    lambda.create(this.getLambdas(functions))
+
+    const http = new Http(this.serverless, this.mergeServerlessOfflineOptions(), lambda)
+
+    await http.createServer()
+
+    http.create(this.getEvents(functions))
+    http.createResourceRoutes()
+    http.create404Route()
+
+    await http.start()
+  }
+}

package.json

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+{
+  "name": "serverless-offline-lambda-function-urls",
+  "version": "0.1.0",
+  "license": "ISC",
+  "description": "An extension off serverless-offline that adds support to lambda function urls",
+  "type": "module",
+  "main": "./index.js",
+  "files": [
+    "index.js"
+  ],
+  "bugs": {
+    "url": "https://github.com/MarioSimou/serverless-offline-lambda-function-urls/issues"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/MarioSimou/serverless-offline-lambda-function-urls.git"
+  },
+  "scripts": {
+    "prettier": "prettier '.'",
+    "prettier:check": "pnpm prettier -c",
+    "prettier:format": "pnpm prettier -l -w ",
+    "clean": "rm -rf node_modules 2>dev/null"
+  },
+  "peerDependencies": {
+    "serverless-offline": ">= 12.x"
+  },
+  "keywords": [
+    "serverless-offline",
+    "Lambda Function Urls"
+  ],
+  "author": "Marios Simou",
+  "contributors": [
+    {
+      "name": "Marios Simou",
+      "url": "https://www.mariossimou.dev",
+      "author": true
+    }
+  ]
+}