Identification of TypeScript patterns & conventions

[samreid]

Part of our migration to TypeScript #1046 will involve discovery and identification of patterns & conventions for how we wish to use TypeScript. Here is an initial list, which is expected to grow as we learn more:

• How should we implement Enumerations? Should we use string literals or enum? See https://thisthat.dev/literal-union-type-vs-string-enums/. enum would be fine if we have a lint rule for matching key names to values. Otherwise, string literal unions seems good? May still need EnumerationIO for phet-io ones? Or will we want a lightweight EnumerationIO that complements string union? Vanderkam book recommends string literal union since it works via structural typing like the rest of typescript rather than named typing. Typescript Convention: How should we implement enumerations with TypeScript? #1106
• Should we still use JSDoc the same way? Like function parameters, etc. Don't repeat type information in documentation, Investigate use of Typescript tasks#987 (comment) TypeScript Convention: Should we repeat type information in the JSDoc? #1110
• Mixins? I checked that the pattern described in https://www.typescriptlang.org/docs/handbook/mixins.html has great IDE support.
• Using type vs interface?
  https://www.typescriptlang.org/docs/handbook/2/everyday-types.html#differences-between-type-aliases-and-interfaces says

"If you would like a heuristic, use interface until you need to use features from type."

[samreid]

All of the above problems are being addressed in separate issues. Closing.