Azure-Middy-Core

Install

To install middy you can use NPM:

npm install --save @kevboutin/azure-middy-core

Usage

The core middleware engine provides a powerful way to compose Azure Functions with middleware.

JavaScript (CommonJS)

const middy = require("@kevboutin/azure-middy-core");

const baseHandler = async (req, context) => {
    return {
        body: JSON.stringify({ message: "Success" }),
    };
};

const handler = middy(baseHandler)
    .use(loggingMiddleware)
    .use(errorHandlingMiddleware);

module.exports = { handler };

TypeScript

import middy, {
    MiddyInstance,
    Middleware,
    Plugin,
} from "@kevboutin/azure-middy-core";
import type { AzureFunctionRequest } from "@kevboutin/azure-middy-types";

const baseHandler = async (req: any, context: any) => {
    return {
        body: JSON.stringify({ message: "Success" }),
    };
};

const loggingMiddleware: Middleware = {
    before: async (request: AzureFunctionRequest) => {
        console.log("Request:", request.req.method, request.req.url);
    },
    after: async (request: AzureFunctionRequest) => {
        console.log("Response:", request.response);
    },
    onError: async (request: AzureFunctionRequest) => {
        console.error("Error:", request.error);
    },
};

const monitoringPlugin: Plugin = {
    requestStart: () => console.log("Request started"),
    requestEnd: () => console.log("Request ended"),
};

const handler: MiddyInstance = middy(baseHandler, monitoringPlugin).use(
    loggingMiddleware,
);

export { handler };

TypeScript Support

This package includes full TypeScript support with:

• Type Definitions: Complete type definitions for all middleware interfaces and functions
• Type Safety: Full type checking for middleware, plugins, and request objects
• IntelliSense: Enhanced IDE support with autocomplete and type hints

Available Types

import {
    MiddyInstance,
    Middleware,
    Plugin,
    MiddlewareFunction,
    BaseHandler,
} from "@kevboutin/azure-middy-core";
import type { AzureFunctionRequest } from "@kevboutin/azure-middy-types";

TypeScript Configuration

To use TypeScript with this package, ensure your tsconfig.json includes:

{
    "compilerOptions": {
        "esModuleInterop": true,
        "moduleResolution": "node"
    }
}

Documentation and examples

For more documentation and examples, refer to the main Azure-middy monorepo on GitHub.

Contributing

Everyone is very welcome to contribute to this repository. Feel free to raise issues or to submit Pull Requests.

License

Licensed under MIT License. Copyright (c) 2024 Kevin Boutin, and the Azure-Middy team.