feat(idempotency): create initial class structure for function idempotency

packages/idempotency/LICENSE-THIRD-PARTY

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+@aws-lambda-powertools/commons
+0.0.2 <https://github.com/awslabs/aws-lambda-powertools-typescript>
+license: MIT*
+authors: Amazon Web Services <https://aws.amazon.com>
+
+******************************
+
+@types/aws-lambda
+8.10.87 <https://github.com/DefinitelyTyped/DefinitelyTyped>
+    MIT License
+
+    Copyright (c) Microsoft Corporation.
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE
+
+
+******************************
+
+lodash
+4.17.21 <https://github.com/lodash/lodash>
+Copyright OpenJS Foundation and other contributors <https://openjsf.org/>
+
+Based on Underscore.js, copyright Jeremy Ashkenas,
+DocumentCloud and Investigative Reporters & Editors <http://underscorejs.org/>
+
+This software consists of voluntary contributions made by many
+individuals. For exact contribution history, see the revision history
+available at https://github.com/lodash/lodash
+
+The following license applies to all parts of this software except as
+documented below:
+
+====
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+====
+
+Copyright and related rights for sample code are waived via CC0. Sample
+code is defined as all source code displayed within the prose of the
+documentation.
+
+CC0: http://creativecommons.org/publicdomain/zero/1.0/
+
+====
+
+Files located in the node_modules and vendor directories are externally
+maintained libraries used by this software which have their own
+licenses; we recommend you read them, as their terms may differ from the
+terms above.

packages/idempotency/README.md

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+# AWS Lambda Powertools for TypeScript
+
+A suite of utilities for AWS Lambda functions to ease the adoption of best practices such as tracing, structured logging, custom metrics, and more.
+
+You can use the library in both TypeScript and JavaScript code bases.
+
+AWS Lambda Powertools for [Python](https://github.com/awslabs/aws-lambda-powertools-python) and  AWS Lambda Powertools for [Java](https://github.com/awslabs/aws-lambda-powertools-java) are also available.
+
+**[📜 Documentation](https://awslabs.github.io/aws-lambda-powertools-typescript/)** | **[NPM](https://www.npmjs.com/org/aws-lambda-powertools)** | **[Roadmap](https://github.com/awslabs/aws-lambda-powertools-roadmap/projects/1)** | **[Examples](https://github.com/awslabs/aws-lambda-powertools-typescript/tree/main/examples)** | **[Serverless TypeScript Demo](https://github.com/aws-samples/serverless-typescript-demo)**
+
+## Table of contents
+
+- [Features](#features)
+- [Getting started](#getting-started)
+  - [Installation](#installation)
+  - [Examples](#examples)
+  - [Serverless TypeScript Demo](#serverless-typescript-demo-application)
+- [Contribute](#contribute)
+- [Roadmap](#roadmap)
+- [Connect](#connect)
+- [Credits](#credits)
+- [License](#license)
+
+## Features
+
+* **[Tracer](https://awslabs.github.io/aws-lambda-powertools-typescript/latest/core/tracer/)** - Utilities to trace Lambda function handlers, and both synchronous and asynchronous functions
+* **[Logger](https://awslabs.github.io/aws-lambda-powertools-typescript/latest/core/logger/)** - Structured logging made easier, and a middleware to enrich log items with key details of the Lambda context
+* **[Metrics](https://awslabs.github.io/aws-lambda-powertools-typescript/latest/core/metrics/)** - Custom Metrics created asynchronously via CloudWatch Embedded Metric Format (EMF)
+
+## Getting started
+
+Find the complete project's [documentation here](https://awslabs.github.io/aws-lambda-powertools-typescript).
+
+### Installation
+
+The AWS Lambda Powertools for TypeScript utilities follow a modular approach, similar to the official [AWS SDK v3 for JavaScript](https://github.com/aws/aws-sdk-js-v3).  
+Each TypeScript utility is installed as standalone NPM package.
+
+Install all three core utilities at once with this single command:
+
+```shell
+npm install @aws-lambda-powertools/logger @aws-lambda-powertools/tracer @aws-lambda-powertools/metrics
+```
+
+Or refer to the installation guide of each utility:
+
+👉 [Installation guide for the **Tracer** utility](https://awslabs.github.io/aws-lambda-powertools-typescript/latest/core/tracer#getting-started)
+
+👉 [Installation guide for the **Logger** utility](https://awslabs.github.io/aws-lambda-powertools-typescript/latest/core/logger#getting-started)
+
+👉 [Installation guide for the **Metrics** utility](https://awslabs.github.io/aws-lambda-powertools-typescript/latest/core/metrics#getting-started)
+
+### Examples
+
+* [CDK](https://github.com/awslabs/aws-lambda-powertools-typescript/tree/main/examples/cdk)
+* [SAM](https://github.com/awslabs/aws-lambda-powertools-typescript/tree/main/examples/sam)
+
+### Serverless TypeScript Demo application
+
+The [Serverless TypeScript Demo](https://github.com/aws-samples/serverless-typescript-demo) shows how to use Lambda Powertools for TypeScript.  
+You can find instructions on how to deploy and load test this application in the [repository](https://github.com/aws-samples/serverless-typescript-demo).
+
+## Contribute
+
+If you are interested in contributing to this project, please refer to our [Contributing Guidelines](https://github.com/awslabs/aws-lambda-powertools-typescript/blob/main/CONTRIBUTING.md).
+
+## Roadmap
+
+The roadmap of Powertools is driven by customers’ demand.  
+Help us prioritize upcoming functionalities or utilities by [upvoting existing RFCs and feature requests](https://github.com/awslabs/aws-lambda-powertools-typescript/issues), or [creating new ones](https://github.com/awslabs/aws-lambda-powertools-typescript/issues/new/choose), in this GitHub repository.
+
+## Connect
+
+* **AWS Lambda Powertools on Discord**: `#typescript` - **[Invite link](https://discord.gg/B8zZKbbyET)**
+* **Email**: aws-lambda-powertools-feedback@amazon.com
+
+## Credits
+
+Credits for the Lambda Powertools idea go to [DAZN](https://github.com/getndazn) and their [DAZN Lambda Powertools](https://github.com/getndazn/dazn-lambda-powertools/).
+
+## License
+
+This library is licensed under the MIT-0 License. See the LICENSE file.

packages/idempotency/jest.config.js

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+module.exports = {
+  displayName: {
+    name: 'AWS Lambda Powertools utility: IDEMPOTENCY',
+    color: 'cyan',
+  },
+  'runner': 'groups',
+  'preset': 'ts-jest',
+  'transform': {
+    '^.+\\.ts?$': 'ts-jest',
+  },
+  moduleFileExtensions: [ 'js', 'ts' ],
+  'collectCoverageFrom': [
+    '**/src/**/*.ts',
+    '!**/node_modules/**',
+  ],
+  'testMatch': ['**/?(*.)+(spec|test).ts'],
+  'roots': [
+    '<rootDir>/src',
+    '<rootDir>/tests',
+  ],
+  'testPathIgnorePatterns': [
+    '/node_modules/',
+  ],
+  'testEnvironment': 'node',
+  'coveragePathIgnorePatterns': [
+    '/node_modules/',
+    '/types/',
+  ],
+  'coverageThreshold': {
+    'global': {
+      'statements': 100,
+      'branches': 100,
+      'functions': 100,
+      'lines': 100,
+    },
+  },
+  'coverageReporters': [
+    'json-summary',
+    'text',
+    'lcov'
+  ],
+  'setupFiles': [
+    '<rootDir>/tests/helpers/populateEnvironmentVariables.ts'
+  ]
+};

packages/idempotency/package.json

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+{
+  "name": "@aws-lambda-powertools/idempotency",
+  "version": "0.0.11",
+  "description": "The idempotency package for the AWS Lambda Powertools for TypeScript library. It provides options to make your Lambda functions idempotent and safe to retry.",
+  "author": {
+    "name": "Amazon Web Services",
+    "url": "https://aws.amazon.com"
+  },
+  "publishConfig": {
+    "access": "public"
+  },
+  "scripts": {
+    "commit": "commit",
+    "test": "npm run test:unit",
+    "test:unit": "jest --group=unit --detectOpenHandles --coverage --verbose",
+    "test:e2e:nodejs12x": "RUNTIME=nodejs12x jest --group=e2e",
+    "test:e2e:nodejs14x": "RUNTIME=nodejs14x jest --group=e2e",
+    "test:e2e:nodejs16x": "RUNTIME=nodejs16x jest --group=e2e",
+    "test:e2e": "jest --group=e2e",
+    "watch": "jest --watch --group=unit",
+    "build": "tsc",
+    "lint": "eslint --ext .ts --fix --no-error-on-unmatched-pattern src tests",
+    "format": "eslint --fix --ext .ts --fix --no-error-on-unmatched-pattern src tests",
+    "package": "mkdir -p dist/ && npm pack && mv *.tgz dist/",
+    "package-bundle": "../../package-bundler.sh logger-bundle ./dist",
+    "prepare": "npm run build",
+    "prepublishOnly": "npm test && npm run lint",
+    "preversion": "npm run lint",
+    "version": "npm run format && git add -A src",
+    "postversion": "git push && git push --tags"
+  },
+  "homepage": "https://github.com/awslabs/aws-lambda-powertools-typescript/tree/master/packages/idempotency#readme",
+  "license": "MIT",
+  "main": "./lib/index.js",
+  "types": "./lib/index.d.ts",
+  "typedocMain": "src/index.ts",
+  "files": [
+    "lib"
+  ],
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/awslabs/aws-lambda-powertools-typescript.git"
+  },
+  "bugs": {
+    "url": "https://github.com/awslabs/aws-lambda-powertools-typescript/issues"
+  },
+  "dependencies": {
+    "@aws-lambda-powertools/commons": "^1.2.1"
+  },
+  "keywords": [
+    "aws",
+    "lambda",
+    "powertools",
+    "serverless",
+    "nodejs"
+  ]
+}

packages/idempotency/src/IdempotencyOptions.ts

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+import { PersistenceLayer } from './persistence/PersistenceLayer';
+
+type IdempotencyOptions = {
+  dataKeywordArgument: string
+  persistenceStore: PersistenceLayer
+};
+
+export { IdempotencyOptions };

packages/idempotency/src/makeFunctionIdempotent.ts

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+/* eslint-disable @typescript-eslint/no-explicit-any */
+import { AnyFunction } from './types/AnyFunction';
+import { IdempotencyOptions } from './IdempotencyOptions';
+
+const makeFunctionIdempotent = <U>(
+  fn: AnyFunction<U>,
+  _options: IdempotencyOptions
+): (...args: Array<any>) => Promise<U | void> => (...args) => fn(...args);
+
+export { makeFunctionIdempotent };

packages/idempotency/src/persistence/DynamoDbPersistenceLayer.ts

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+/* eslint-disable @typescript-eslint/no-empty-function */
+import { IdempotencyRecord, PersistenceLayer } from './PersistenceLayer';
+
+class DynamoDBPersistenceLayer extends PersistenceLayer {
+  public constructor(_tableName: string, _key_attr: string = 'id') {
+    super();
+  }
+  protected async _deleteRecord(): Promise<void> {}
+  protected async _getRecord(): Promise<IdempotencyRecord> {
+    return Promise.resolve({} as IdempotencyRecord);
+  }
+  protected async _putRecord(_record: IdempotencyRecord): Promise<void> {}
+  protected async _updateRecord(): Promise<void> {}
+}
+
+export {
+  DynamoDBPersistenceLayer
+};