add codefix that rewrites var to let to const where appropriate

[zpdDG4gta8XKpMCd]

consider adding a codefix that transforms var to let to const by picking strictest declaration possible

[mhegazy]

We can do a refactoring for this. will have to think about cases where the var declaration is used outside the block where it is defined, we will need to hoist the declaration as well as change it to block-scoped declaration.

[zpdDG4gta8XKpMCd]

btw are refactorings even a thing that is somehow different from codefixes (i am asking because i see different tags are used to label similar issues)?

[DanielRosenwasser]

A code fix usually implies something is wrong - there's an error that can be amended. A refactoring implies rewriting working code in some manner. I think they both fall under the umbrella of "code actions".

In general, I've been sloppy with the terminology with @paulvanbrenk correcting me every so often.

[mhegazy]

btw are refactorings even a thing that is somehow different from codefixes (i am asking because i see different tags are used to label similar issues)?

Code Fix is tied to a diagnostic message, e.g. an error. If the error is shown, the editor shows you the option to "fix" it.

Refactoring are more free form. you would right-click on a position and ask for possible refactorings.

it is possible that you have the same change available as a Fix and as a refactoring.

[angelozerr]

tslint supports that. I have started to write a tslint plugin (for TypeScript 2.2.1) https://github.com/angelozerr/tslint-language-service . Here a demo with Eclipse but it works too with other IDE like VSCode:

[zpdDG4gta8XKpMCd]

why does it turn into let instead of const on the annimation?