[no-restricted-imports] Allow configuring severity at the path level so both errors and warnings are possible

[dshook]

The version of ESLint you are using.
6.8.0

The problem you want to solve.
I want to be able to configure the no-restricted-imports rule to have some paths be errors and others only be warnings. After looking at the docs, the source for the rule, and much searching I couldn't find any way to configure it to do that. I believe this is a broader configuration issue than just the no-restricted-imports but this is the current rule I'm running into the roadblock with.

In JSON configuration

    "no-restricted-imports": [
      "error",
      {
        "paths": [
          {
            "name": "somepackage",
            "message": "I want to make this one an error"
          },
          {
            "name": "otherpackage",
            "message": "But this should only be a warning"
          },
        ],
      }
    ],

Your take on the correct solution to problem.

    "no-restricted-imports": [
      "error",
      {
        "paths": [
          {
            "name": "somepackage",
            "message": "I want to make this one an error"
          },
          {
            "name": "otherpackage",
            "message": "But this should only be a warning. By providing a severity here it overrides the severity set above",
            "severity": "warn"
          },
        ],
      }
    ],

Are you willing to submit a pull request to implement this change?
No

[mdjermanovic]

Hi @dshook, thanks for the issue!

This request looks similar to #13831.

Supporting this would require a lot of changes in ESLint's design, for maybe only a few rules where it would be useful.

As a workaround, you can make a clone of the rule and then configure the two rules separately (e.g., the original rule as "error", and its clone as "warn").

[dshook]

Thanks for the quick reply!

Just to be clear, when you say clone you mean using one of the other packages (like eslint-rule-extender or eslint-rule-composer mentioned in the other issue) right? I can't just put another instance of the no-restricted-imports in the config since it's a key of the rules object.

[mdjermanovic]

Yes, it should be two different rules, seemingly unrelated to each other.

eslint-rule-extender or eslint-rule-composer are actually not necessary if we just want to clone a rule without any modifications. New rule can just "re-export" the existing one, so this would be all the code of the new rule:

const eslint = require("eslint");

module.exports = new eslint.Linter().getRules().get("no-restricted-imports");

Now you can use this module as a custom rule with --rulesdir. For example, the above code can be placed in my-rules/no-restricted-imports-clone.js, and then the two rules would be configured like this:

  rules: {
    "no-restricted-imports": [
      "error",
      {
        "paths": [
          {
            "name": "somepackage",
            "message": "I want to make this one an error"
          }
        ],
      }
    ],
    "no-restricted-imports-clone": [
      "warn",
      {
        "paths": [
          {
            "name": "otherpackage",
            "message": "But this should only be a warning"
          },
        ],
      }
    ]
  },

ESLint would be run with --rulesdir my-rules.

Another option is to make a plugin. For an example of a plugin that doesn't have to be published, you can see our internal rules used for this project only:

eslint/package.json

Line 102 in 4cab165

"eslint-plugin-internal-rules": "file:tools/internal-rules",

The plugin is in https://github.com/eslint/eslint/tree/master/tools/internal-rules

[kylecombes]

Thanks, this works great! The only thing I had to add is an /* eslint-disable */ to the top of the rule file (otherwise it complained about not being able to find the rule it was defining).

I'm getting a ESLint: Definition for rule 'no-restricted-imports-clone' was not found. (no-restricted-imports-clone) when trying that approach. I'm going to try defining a plugin tomorrow and see if that works for us.

[kylecombes]

Looks like configuring it as a plugin (following this guide) worked.

[nzakas]

Resolved, so closing.

[BarbecueSilver]

I am having the same issue, that we want warnings as well as errors for imports.
Thanks for pointing out, how to work around this issue 👍