Run funcpack on file change

[cameronk]

When developing functions locally, it seems fairly common to use the func run <functionName> command from azure-functions-cli.

The local function host offers a "live reload" feature that reloads the server after file changes. It would be great if there was a funcpack watch command that observed source changes and automatically ran the webpack config, so that the command didn't have to be manually re-run after source changes.

[christopheranderson]

It's a good feature request. I can see if I can find any file watching utilities I can just throw in and try it out.