Port to TypeScript

[samreid]

To help move TypeScript forward and to get the benefits of TypeScript in this repo, we should port it to TypeScript.

[samreid]

Summarizing work so far. It took nearly 3 hours to port all of bending light (8900 lines) to TypeScript. WebStorm tooling provided good support with tooling like "infer types from JSDoc" and "promote to property". The port is not complete due to the following:

• 76 @ts-ignore, mainly due to strings, and inadequacies in common code
• implicit any due to numerous non-generic Property and Emitter
• 58 explicit : any due to inadequancy in common code
• Some type casting to unknown and to the type, due to inadequancy in common code
• I haven't added types for the options yet, they are all typed as options?:any
• Several TODOs marked
• Incomplete enumeration support

I discovered numerous problems in this port so far, like:

• Using less than operator to compare number and string.
• Passing Path options to Shape
• Places where options are passed through but not received.
• Numerous bad JSDoc types
• Numerous sloppy types, where not all types were being handled properly (mostly around null initializers)

[samreid]

In the commits, I added type declaration for strings, better enum support and addressed several TODOs. Total time so far: about 9.5 hours. What's left:

• 42 ts-ignore
• 1 any
• 7 TODO (many from pre-existing problems)

Many of the existing problems are due to inadequacies in common code. I can add better types for options, and look through the any and ts-ignore again, but many things may need to wait until we have common code support.

[samreid]

This port is is good shape and I don't plan other work at the moment. Closing.