Fork-ts-checker-webpack-plugin: It tries to lint json files as ts files

[beckend]

import * as pJSON from './package.json'

ERROR in package.json
ERROR in package.json(1,1):
no-unused-expression: unused expression, expected an assignment or function call

and of course many more errors

[johnnyreilly]

I think you may want to raise a bug with tslint?

[beckend]

I suppose then this plugin is simply using tslint, alright

[beckend]

But what a moment...I just linted the file with tslint manually, this error is only present when using this plugin

[Tenga]

Can confirm that the problem is specific to tslint being run through fork-ts-checker-webpack-plugin.

tslint has implemented a check to avoid this here, therefore it no longer happens by directly calling tslint, even without any special configuration.

fork-ts-checker-webpack-plugin also seems to either ignore or override linterOptions.exclude array from the specified tslint config, which was a config based fix for this issue for manually ran lints until that fix was released.

[alexkirsz]

I muted this error by adding "**/*.json" to my linterOptions.exclude array in tslint.json

[beark]

Running into this issue too. Adding "linterOptions": { "exclude": ["**/*.json"]} to the relevant tslint.json did not do anything for me. Running tslint manually on the project results in no errors.

[johnnyreilly]

It's worth considering starting to move to ESLint now that TSLint is deprecated. We're not planning further work on TSLint support for that reason

[beark]

By judicious sprinkling of console.log statements, I think I may have figured this out!

In ApiIncrementalChecker.initLinterConfig, if I print the value of linterOptions.exclude, they have all been resolved as absolute paths. Ie, say my project is located in /wherever/project/packages/subproject, then at the time the linter is initialized, the "**/*.json" exclude is transformed to /wherever/project/packages/subproject/**/*.json. The issue with this is that the root project is host to many packages/sub-projects, and the .jsons I'm importing belong to _another_ sub-project, something like: /wherever/project/packages/anotherproject/foo/bar.json. So the exclude filter does not match it.

My workaround was to set the following tslint.json in "subproject":

{
  "extends": "@myorg/our-tslint-rules",
  "linterOptions": {
    "//": "Workaround for https://github.com/TypeStrong/fork-ts-checker-webpack-plugin/issues/207",
    "exclude": ["../../../**/*.json"]
  }
}

[johnnyreilly]

console.log answers many questions 😁