simple-functions

Simple functions emulator for local development

CLI Options

• -p, --port: specify emulator port to run, defaults to 32245
• -s, --functionsPath: specify a path to look for functions, defaults to functions
• -f, --functions: specify which functions to run on emulator, if not present, runs all functions.

Run Examples

npm start -- -s examples or npm start -- -s example -f echo,hello-world

Function Structure

Each function should export default one function to be used by server. Additionally you can export an init function to do some work before the function is registered.

Example:

// ./examples/react-ssr/index.js

const utils = require('./utils');

module.exports = function (context) {
  const props = {
    name: 'Stream'
  }

  const html = utils.renderClient(props);

  return html;
}

module.exports.init = async function () {
  const path = require('path');
  const targetPath = path.resolve(__dirname, '../__react-app/dist/server.bundle.js');

  await utils.downloadClient(targetPath);
}

Function Context

This section is under development, currently there is only 1 parameter available for functions and it only has, request parameter comes from express.req oject

Config File

You need to create a functions.config.json on the root level of your functions folder

functions: Array

• name: Required. Name of the function, this is used to call function from cli
• path: Required. Function path to be exposed from server
• entry: Required. Entry file path of the function
• method: HTTP method for the function, defaults to GET

Example config file

{
  "functions": [
    {
      "name": "echo",
      "path": "/echo",
      "entry": "echo/index.js",
      "method": "GET"
    },
    {
      "name": "hello-world",
      "path": "/hello-world",
      "entry": "hello-world/index.js",
      "method": "GET"
    }
  ]
}

TODOS

• Handle local function dependencies, thanks to nodejs module structre we might not need this for nodejs functions
• Figure out how to implement middlewares for nodejs applications
• Potentially add other languages in the long run