[DO NOT MERGE] Reproduce internal error in tsc

[brodycj]

This PR shares many commits in common with PR #6 for strict JSDoc type linting.

The following update in 032d29d causes tsc 3.6.4 to crash:

commit 032d29dd715a78e7a84567bfbefb63faf43cc939
Author: Christopher J. Brody <chris@brody.consulting>
Date:   Fri Nov 1 15:54:25 2019 -0400

    [TBD] add @typedef JSDoc comment to module.exports in lib/program-helper.js - tsc (version 3.6.4) seems to throw an internal error at this point

diff --git a/lib/program-helper.js b/lib/program-helper.js
index 4226780..619ffce 100644
--- a/lib/program-helper.js
+++ b/lib/program-helper.js
@@ -118,4 +118,7 @@ Helper.getOptions = function () {
     return commander;
 };
 
+/**
+ * @typedef {object} Helper
+ */
 module.exports = Helper;

This seems to be an interesting case of microsoft/TypeScript#32231.

I think there is more work I have to do to export the correct helper object type.

/cc @rbiggs

[rbiggs]

I think that's failing because you trying to type a complex object with properties as just Object. Object is very generic, equivalent to type any. But it's useful for building up type definitions for complex objects. When you use @typedef think of it as the same as TypeScript interface. Then use @prop to define properties on that object. After creating a type definition, you need to type the object using `/** @type {SomeType} */ right before the object you want to type.

I took the liberty to look at your Helper function. I think what you want is something like this:

/**
 * @typedef {Object} Helper
 * @prop {() => string} getTSCCommand
 * @prop {() => any[]} resolveTSFiles
 * @prop {() => Command} getOptions
 */

// Apply the above type to the Helper object:
/** @type {Helper} */
module.exports = Helper;

But I'm not sure is that's the best place to be designating Helper's type. Give it a try and let me know if it explodes.

[rbiggs]

Ok, I downloaded this and took a good look at it. First main problem, TypeScript hates expando properties. You were create Helper as {} and then tacking methods on with dot notation. TypeScript cannot understand those. So I refactored you object which fixed that problem. Next I had a problem where you were importing the package.json. TypeScript needs a special flag for that so I added it to my tsconfig.json file. Oh, and I added a tsconfig.json file to organize all these TypeScript options. That means the npm script is just:

"scripts": {
   "checks": "tsc"
}

Here's a link to my repository: https://github.com/rbiggs/glob-tsc-dev

If you want. I can fork this, fix it and send you a pull request.