Build process/contributor instructions

[scottdover]

Hey @scnwwu . I was helping @clangsmith debug an issue a few days ago around our build process and had a few questions.

First, here are steps to reproduce the issue:

• Start with a clean repo (no build files)
• Click launch client
• Create a new sas notebook
• Run some code

This will show you an error because some of the assets aren't built with the npm watch command. In this case, the solution was to first run npm compile-browser, then npm watch.

There are a few solutions I can think of:

• Update CONTRIBUTING.md to instruct the contributor to first run npm install && npm run vscode:prepublish
• Update watch to watch both browser and client
• Update our preLaunchTask to target an npm script that runs npm run vscode:prepublish prior to running npm run watch

This also brings up another question I've had for some time. Why do we use both esbuild and webpack to build assets? Would it be a good idea to try to migrate everything to one build tool, or do we need both for some reason?

[scnwwu]

• esbuild has better performance than webpack. So as long as it works, I'd like to use esbuild. There were some issues that we had to use webpack. But esbuild is keep updating, perhaps we can revisit it.
• Relying on vscode:prepublish sounds not ideal. Prepublish is doing production build which is not needed in development.
• Watch both node and browser simultaneously sounds redundant. Normally a developer just launch either client or browser but not both.

As a first step, I'll try to see if I can move the notebook renderer build to esbuild so that the watch script will build everything needed for launch client.

[scottdover]

Sounds good to me :)

[scnwwu]

Done by #485