Cannot override rule in shared config

[chazzlabs]

ESLint v1.6.0

In my .eslintrc, I'm extending the AirBnb config and overriding a rule like this:

{
    "extends": "airbnb",
    "rules": {
        "indent": 2
    }
}

I couldn't find an example elsewhere, but eslint-config-airbnb v0.1.0 is overriding a rule the same way in its .eslintrc file so I assume what I have is correct. However, I'm seeing the following output when I run eslint scripts/**:

C:\dev\my-project\scripts\index.js
  2:5  error    Expected indentation of 2 space characters but found 4  indent
  2:5  warning  Unexpected console statement                            no-console

✖ 2 problems (1 error, 1 warning)

[ilyavolodin]

Can you provide a code that is failing and also specify what did you expect to happen?

[chazzlabs]

@ilyavolodin Sure, sorry. The code is simply:

function run() {
    console.log('Hello, world');
}

exports.run = run;

The documentation for the indent rule (http://eslint.org/docs/rules/indent.html) says the default is 4 spaces and gives the example "indent": 2 for 4-space indentation, so I expected that overriding any extended configs using that configuration for the indent rule would make eslint pass for any files using 4-space indentation.

I've changed my .eslintrc to the following, specifying a number of spaces, and it works now:

{
    "extends": "airbnb",
    "rules": {
        "indent": [2, 4]
    }
}

Perhaps the default space setting for indentation is overridden elsewhere and I'm not aware of it or haven't found it.

[gyandeeps]

Do you know what is the config of indent rule inside your extended config (airbnb)?

[hzoo]

It's [2, 2] - I think it's just because the regular value is either 0, 1, 2. With an option you have to use [error value, config] so [2, 4] worked

Maybe the docs need to be updated

eslint/tests/lib/config-initializer.js

Line 35 in abe3669

assert.deepEqual(config.rules.indent, [2, 2]);

[chazzlabs]

Yes, the airbnb config has "indent": [2, 2]. Based on the docs I linked previously I assumed "indent": 2 would use a default of 4 spaces.

[gyandeeps]

This is the expected behavior. If you just change the error level then we do inherit the options from the extended config.

[chazzlabs]

Thanks, @gyandeeps. The only mention of overriding extended configs that I found was on http://eslint.org/docs/developer-guide/shareable-configs.html, and it only says, "You can override settings from the shareable config by adding them directly into your .eslintrc file."

[nzakas]

It's mentioned on the primary configuration documentation: http://eslint.org/docs/user-guide/configuring#extending-configuration-files

[danny-andrews]

This behavior still seems confusing to me, and (as far as I understand it) makes it impossible to override certain rule options (see #6144). Also, @nzakas, I don't see anywhere in the docs where it explains that rule options will be inherited from extended configs, just that rules can be overridden in the child configs. I was lead to believe that if you specified a rule in a child config, it would completely negate any rules of the same name in extended configs, resorting back to that rule's default options if none are specified.

[jsejcksn]

@nzakas Can you give us a response to what @danny-andrews brought up? It is very confusing.

[not-an-aardvark]

This has been discussed in #6144 and #6361. It appears that the resolution of those discussions was also to leave the overriding behavior as-is. However, we are certainly open to PRs to improve the docs to hopefully make this less confusing.