Tslint: Error: no-for-in-array requires type checking

Created on 29 Jul 2016 · 18Comments · Source: palantir/tslint

Bug Report

TSLint version: 3.14.0
TypeScript version: 2.0.0
Running TSLint via: Node.js API

TypeScript code being linted

with tslint.json configuration:

{
    "linterOptions": {
        "typeCheck": true
    },
    "rules": {
        "no-for-in-array": true
    }
}

Actual behavior

Error: no-for-in-array requires type checking
at Rule.TypedRule.apply (...\node_modules\tslint\lib\language\rule\typedRule.js:14:15)
at Linter.lint (...\node_modules\tslint\lib\tslint.js:65:37)
...

Expected behavior

No errors

Question

Source

Delagen

Most helpful comment

@adidahiya What is the point that you do not make this API public?
I guess it will be very useful to set all TSLint settings via tslint.json.

timocov on 16 Jan 2017

👍21

All 18 comments

linterOptions in tslint.json is actually a private API. If using the CLI, you must use the --type-check flag. If using the Node.js APIs, you'll need to follow a pattern similar to src/test.ts.

adidahiya on 30 Jul 2016

This is ugly and must be public

Delagen on 31 Jul 2016

👍4

Well, it's not a documented API... how did you discover it? We reserve the right to experiment with APIs in our project before committing to them...

adidahiya on 1 Aug 2016

Reading code of sample configurations, and reading code is the best documentation in most javascript projects. Developers update documentation very slow, released features may be documented after long time, some projects does not provide documentation about Node API use totally prefer to offer only CLI use, that is ugly.

Delagen on 2 Aug 2016

Many build tools plugins use Node.JS api, and it's functionality must not differ from CLI, because CLI does not provide ability to control process of output etc.
For example: https://github.com/panuhorsmalahti/gulp-tslint/blob/master/index.js

Delagen on 2 Aug 2016

reading code is the best documentation in most javascript projects

Sure, that's partially true -- that's why I pointed out src/test.ts in my comment above.

I agree that the Node.js API is useful and should be documented. We _do_ have documentation for parts that are well-supported, including type checking, right here in the README. Also, being a typescript project, we naturally have documentation in the form of typings declaration files published in the NPM package.

Sure, the GH pages site is a little behind compared to the README -- we're working on improving that. But I might suggest a slightly different tone for your form of contribution here -- you will probably experience more success by, say, sending a documentation PR before calling a project "ugly".

adidahiya on 6 Aug 2016

The GH pages site is now updated with the latest rule metadata from the most recent release. (I realize this is a little tangential to the issue at hand though.)

Currently, tslint.json files _only specify how individual files should be linted_ and _do not specify overarching linter options_. Allowing tslint.json files to specify overarching options is a bit of a paradigm change, and that's why we're experimenting with some new setups internally before changing any public-facing API.

jkillian on 7 Aug 2016

Just ran into that error after attempting to enable no-for-in-array in a tslint.json, and this GH issue was the only Google result that popped up. Can the error message at least point to documentation?

As a side note, is there documentation on enabling it for the Gulp runner?

JoshuaKGoldberg on 14 Aug 2016

Not sure with regards to the Gulp runner. We need to update the docs site to make it more clear which rules require typechecking and what that means

jkillian on 17 Aug 2016

Can u plz tell me how would I deal with this issue on an IDE like webstorm?

StevenDoesStuffs on 20 Aug 2016

Could you plz make linterOptions typecheck public or something?

StevenDoesStuffs on 20 Aug 2016

Actually, I think making type checking a rule would be more useful and accessible.

StevenDoesStuffs on 20 Aug 2016

👍7 👎2

Any updates?

StevenDoesStuffs on 4 Sep 2016

@StevenTheEVILZ just disable the rule in your tslint.json. The Webstorm plugin needs to be updated to support the new type checking APIs -- that's external to this repo. This needs to happen regardless of linterOptions in tslint.json being public (I assume they're using the Node.js APIs, not the CLI, in the plugin).

adidahiya on 19 Sep 2016

@adidahiya I've already fixed the problem by using the tslint js lib. BTW they are using the cli and capturing its output.

StevenDoesStuffs on 20 Sep 2016

@adidahiya What is the point that you do not make this API public?
I guess it will be very useful to set all TSLint settings via tslint.json.

timocov on 16 Jan 2017

👍21

I'm using create-react-app with react-scripts-ts and keep getting Warning: The 'no-use-before-declare' rule requires type information. because there's no way for me to specify command line parameters. I don't really understand what is the reasoning for not being able to specify all options in tslint.json.