Rules redefining: shallow or deep?

What version of ESLint are you using?

2.11.1

What parser (default, Babel-ESLint, etc.) are you using?

default

Please show your full configuration:

{
  "extends": [
    "eslint:recommended",
    "airbnb-base"
  ],

  "rules": {
    "eqeqeq": 2,
    "no-console": 0
  }
}

What did you do?..

After reading the documentation about cascading, hierarchy and rules redefining, I wrongly supposed that rules in the user .eslintrc file redefine rules in the extends files as a whole, i.e. if the airbnb-base sets 'no-unused-vars': [2, { 'vars': 'local', 'args': 'after-used' }] and I sets "no-unused-vars": 2 the results will be just "no-unused-vars": 2.

However, the eslint --print-config tests have taught me that I should redefine each option from extends file manually (i.e. the results above will be still "no-unused-vars": [2, { "vars": "local", "args": "after-used" }] if I does not redefine vars and args).

Maybe I’ve missed something in the docs. If I have not, maybe it is worth more clarirfication.

However, I don’t understend how can I cancel array options from extends files rules. So, if airbnb-base sets 'eqeqeq': [2, 'allow-null'], how can I cancel 'allow-null'?

With .eslintrc.json example above and this file:

console.log(undefined == null);

console.log(undefined == 0);

eslint says just:

  3:23  error  Expected '===' and instead saw '=='  eqeqeq

✖ 1 problem (1 error, 0 warnings)

and eslint --print-config inticates that result rule is still

"eqeqeq": [2, "allow-null"]

[vsemozhetbyt]

@nzakas So is this an intentional merging scheme?

eqeqeq: [2, "allow-null"]
+
eqeqeq: 2
=
eqeqeq: [2, "allow-null"]

while

quotes: [2, "single", "avoid-escape"]'
+
quotes: [2, "single"]
=
quotes: [2, "single"]

[michaelficarra]

So we’ll point users to documentation that tells them there’s no way to do something that is very reasonable to want to do? 😟 I don’t think that makes it much better. We should fix this. It’s a broken design.