I’ve been playing around with Azure Functions for quite some time now. However I’ve been trying it with the corresponding Visual Studio Code extension. After all it’s a pretty smooth start, all things are published by Microsoft itself and well documented.

Soon I noticed that access to the filesystem seems to be slow on Azure’s serverless runtime. This is if your code relies on larger amounts of files to be loaded from node_modules, then you’ll face long cold start times. However there’s a simple solution to that: Webpack. And I wanted to go with Typescript anyhow, so let’s use ts-loader as well. How hard can it be.

Since there was no template project for it, I’ve just created a new project template azure-nodejs-typescript over on GitHub. It’s mainly a mashup of aws-nodejs-typescript template and the azure-nodejs one.

To create a new serverless service project based on it, simply run the following (after possibly installing serverless framework globally before):

$ sls create --template-url https://github.com/stesie/azure-nodejs-typescript --name my-new-service
$ cd my-new-service
$ yarn install

It’s just the minimal outline to get you started: a simple hello function with HTTP bindings.

import { IContext, HttpRequest } from 'azure-functions-typedefinitions';

export function hello (context: IContext, req: HttpRequest): void {
  context.log.info('Hello from a typed function!');

  const resBody = {
    invocationId: context.invocationId,
    name: context.executionContext.functionName,
    startTimeUtc: context.bindingData.sys.utcNow


… as you can see it already comes with a dependency on azure-functions-typedefinitions and declares types on both handler arguments. This allows for convenient auto-completion (and type-checking) within context, i.e. context.res.json.

PS: I haven’t noticed those before, but there are helper methods on the context.res object, to fluently construct the response. See the definition of Response class for details.