Support Google Closure Compiler-style type expressions (JSDoc 3.2)

[basickarl]

I'm not sure if this should be put in #145 since that one specifically states TypeScript. Just tell me if it is!

According to the JSDoc 3.2 specification located here https://jsdoc.app/tags-type.html Google Closure Compiler-style type expressions should be supported.

Motivation

People are using TypeScript more and more, there is more information about this type of syntax rather than the old Object.<string, number> syntax which there is less information about.

Current behavior

Causes errors: Syntax error in type: [string, Message][]eslintjsdoc/valid-types

Desired behavior

No errors.

[brettz9]

Your ESLint config either needs to use parser: '@typescript-eslint/parser' or have settings.jsdoc.mode set to 'typescript'.

[basickarl]

@brettz9 Ah that is indeed interesting. I'm curious, why is the mode referred to as "typescript" when it is stated in the JSDoc specification? JSDoc isn't coupled to TypeScript afaiac (I am aware that TypeScript uses Google Closure Compiler-style type expressions, so it happens to work). Shouldn't the "mode" be referred to as "JSDoc-3.2"?

[brettz9]

Firstly, I should say Object.<string, number> is not equivalent to [string, Message][]. The former (which is valid plain jsdoc) means an object with string keys and numeric values whereas the latter would mean an array of two-item arrays (with the first item in the tuple always being a string and the second item always being a Message). While the [] syntax for arrays is supported in plain jsdoc, such "tuples" as [string, Message] (indicating types within array positions) are not supported in jsdoc per jsdoc/jsdoc#1703 nor in Closure per google/closure-compiler#379 though they are in TypeScript. (Note that this "tuple" is different from the stage 2 JavaScript tuple proposal: https://github.com/tc39/proposal-record-tuple .)

[basickarl]

Thank you for taking the time to explain this! I've been with TypeScript for a few years but want to move over to JavaScript + JSDoc and this helped!