Develop Azure Functions with Visual Studio Code

Visual Studio Code (VS Code) is a lightweight but powerful source code editor which runs on your desktop and is available for Windows, macOS, and Linux. It comes with built-in support for JavaScript, TypeScript, and Node.js and has a rich ecosystem of extensions for other languages and runtimes (such as C#, Java, Python, PHP, Go, and .NET Core).

The Azure Functions extension for Visual Studio Code makes it easy to develop, debug, test, and deploy your Azure Functions projects.

Prerequisites

Creating a New Function Project

Once you have the Azure Functions extension installed, you can create a new project directly from VS Code:

Open the Command Palette (Ctrl+Shift+P or Cmd+Shift+P).
Type `Azure Functions: Create New Project` and select it.
Choose a folder for your project.
Select your preferred language (e.g., JavaScript, C#, Python).
Choose a template for your first function (e.g., HTTP trigger, Timer trigger).
Provide a name for your function and set authorization levels if applicable.

VS Code will automatically set up your project structure, including necessary configuration files like local.settings.json and host.json.

Writing Function Code

The Azure Functions extension provides language-specific tooling to help you write your function code efficiently. For example, with JavaScript/TypeScript, you'll work with files like index.js or index.ts and can leverage the context object provided to interact with triggers and bindings.

Example: HTTP Trigger (JavaScript)

                    
    module.exports = async function (context, req) {
        context.log('JavaScript HTTP trigger function processed a request.');

        const name = (req.query.name || (req.body && req.body.name));
        const responseMessage = name
            ? 'Hello, ' + name + '. This HTTP triggered function executed successfully.'
            : 'This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response.';

        context.res = {
            status: 200,
            body: responseMessage
        };
    };
                    
                

Debugging Functions Locally

Debugging your Azure Functions locally in VS Code is a seamless experience. You can set breakpoints, inspect variables, and step through your code:

Ensure Azure Functions Core Tools are installed and accessible.
Set breakpoints in your code by clicking in the gutter next to the line numbers.
Press F5 or go to the Run and Debug view (Ctrl+Shift+D or Cmd+Shift+D) and select "Attach to Azure Functions".
The Functions host will start, and your breakpoints will be hit when the function is triggered.

Use the local.settings.json file to configure application settings and connection strings for local development.

Key Features of the Extension

Project creation for multiple languages.
Local debugging with breakpoints and variable inspection.
Local testing of triggers and bindings.
Easy deployment to Azure.
Integrated Azure resource management.
IntelliSense and code completion for Azure Functions APIs.

Next Steps

After developing and debugging your functions locally, you'll want to deploy them to Azure. The Azure Functions extension provides a streamlined deployment process:

Deploy Azure Functions using Visual Studio Code