New command line help developer experience. - #44157

Still to do things:

• Add Typescript Icon
• Check whether the amount of line break is correct
• plugins shold be in basic category.
• ...

Issues:

1. moduleresolution description of default is changed. I could not find a way to produce line break in Diagnostics

from:
`module === AMD or UMD or System or ES6, then Classic

Otherwise Node`
to:
`module === AMD or UMD or System or ES6, then Classic, Otherwise Node`

2. incremental description of default is changed. This is more consistent with other descriptions.

from:
"`true` if `composite`, `false` otherwise",
to:
"`false`, unless `composite` is set"

3. Add plugin option to Basic Option category, before this PR, it does not belong to any category!
4. As we have any of to tell user candidate values, some description could be changed now. --jsx from Specify JSX code generation: 'preserve', 'react-native', 'react', 'react-jsx' or 'react-jsxdev'. to Specify JSX code generation.. The similar change is applied to target and module

Very cool work! (output)

1. I think if an option is a boolean and the default: is false or undefined or n/a, we can probably drop the 'default' and 'any of' . Might make it a bit less sparse.
2. There's one or two fasles typos in there
3. Wow there's a lot of lib options!
4. Maybe we should drop a few more options from the default. Let me poke some bears about that to see what others think.

There is a strange lint error. I feel it is not related to this PR.

edit: weird! The output of azure and github action tells out of memory. Need some time to find out the reason.

Great work!

I'll tweak this a bunch and see if I can get the linter not bailing too

Confirmed with some logs in the test that there an infinite loop, will look at this tomorrow

Finally, I moved into new house and have spared time....

And thanks a lot to Orta Therox (@orta) 's analytics, it is really helpful.
I found the reason is about child_process, gulp runtests could finish normally, but gulp runtests-parallel cause infinite loop.
In parallel test, process.stdout.columns is undefined.

The related code is in host.ts

process: fork(__filename, [`--config="${configPath}"`], { stdio: ["pipe", "pipe", "pipe", "ipc"] }),

It is easy to test, we could create two files:
tmp.js (main thread)

const {
    Worker, isMainThread, parentPort, workerData,
} = require("worker_threads");

const { fork } = require("child_process");

console.log("main thread: " + __filename);

const child = fork(`${__dirname}/tmp2.js`, [], { stdio: ["pipe", "pipe", "pipe", "ipc"] });

child.stdout.setEncoding("utf8");
child.stdout.on("data", function (data) {
    console.log(data);
});

tmp2.js (child process)

console.log("worker thread stdout columns: "+process.stdout.columns);

The output is worker thread stdout columns: undefined. Try to fix it....

Auh, it seems a little strange for the test case of help now:

1. gulp runtests and gulp runtests-parallel produce different result, please see my last comment.
2. We use the width of terminal to give a pretty output, but the width is pretty easy to be changed, which means gulp runtests will produce a difference expected output for this case! And the test just failed...

What should we do? I feel we need to delete this case, the correspond file is runWithoutArgs.ts

I wonder if we can hardcode the width in the test somehow?

Good suggestion!
And the merge conflict is resolved, we could focus on output now.

I've done some work on getting this ready locally, it's close - I've got to set up all the localization etc. Hopefully should be ready tomorrow.

Alright, let's go.