key-spacing behavior changed from 6.6.0 to 6.7.0 in objects with a single key

[ibc]

Tell us about your environment

$ ./node_modules/.bin/eslint --env-info
Environment Info:

Node version: v12.13.0
npm version: v6.12.0
Local ESLint version: v6.7.0 (Currently used)
Global ESLint version: Not found

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

Default.

Please show your full configuration:

Configuration

{
  "env": {
    "es6": true,
    "node": true,
    "jest/globals": true
  },
  "plugins": [
    "jest"
  ],
  "settings": {},
  "parserOptions": {
    "ecmaVersion": 2018,
    "sourceType": "module",
    "ecmaFeatures": {
      "impliedStrict": true
    }
  },
  "rules": {
    "array-bracket-spacing": [
      2,
      "always",
      {
        "objectsInArrays": true,
        "arraysInArrays": true
      }
    ],
    "arrow-parens": [
      2,
      "always"
    ],
    "arrow-spacing": 2,
    "block-spacing": [
      2,
      "always"
    ],
    "brace-style": [
      2,
      "allman",
      {
        "allowSingleLine": true
      }
    ],
    "camelcase": 2,
    "comma-dangle": 2,
    "comma-spacing": [
      2,
      {
        "before": false,
        "after": true
      }
    ],
    "comma-style": 2,
    "computed-property-spacing": 2,
    "constructor-super": 2,
    "func-call-spacing": 2,
    "generator-star-spacing": 2,
    "guard-for-in": 2,
    "indent": [
      2,
      "tab",
      {
        "SwitchCase": 1
      }
    ],
    "key-spacing": [
      2,
      {
        "singleLine": {
          "beforeColon": false,
          "afterColon": true
        },
        "multiLine": {
          "beforeColon": true,
          "afterColon": true,
          "align": "colon"
        }
      }
    ],
    "keyword-spacing": 2,
    "linebreak-style": [
      2,
      "unix"
    ],
    "lines-around-comment": [
      2,
      {
        "allowBlockStart": true,
        "allowObjectStart": true,
        "beforeBlockComment": false,
        "beforeLineComment": false
      }
    ],
    "max-len": [
      2,
      90,
      {
        "tabWidth": 2,
        "comments": 90,
        "ignoreUrls": true,
        "ignoreStrings": true,
        "ignoreTemplateLiterals": true,
        "ignoreRegExpLiterals": true
      }
    ],
    "newline-after-var": 2,
    "newline-before-return": 2,
    "newline-per-chained-call": 2,
    "no-alert": 2,
    "no-caller": 2,
    "no-case-declarations": 2,
    "no-catch-shadow": 2,
    "no-class-assign": 2,
    "no-confusing-arrow": 2,
    "no-console": 2,
    "no-const-assign": 2,
    "no-debugger": 2,
    "no-dupe-args": 2,
    "no-dupe-keys": 2,
    "no-duplicate-case": 2,
    "no-div-regex": 2,
    "no-empty": [
      2,
      {
        "allowEmptyCatch": true
      }
    ],
    "no-empty-pattern": 2,
    "no-else-return": 0,
    "no-eval": 2,
    "no-extend-native": 2,
    "no-ex-assign": 2,
    "no-extra-bind": 2,
    "no-extra-boolean-cast": 2,
    "no-extra-label": 2,
    "no-extra-semi": 2,
    "no-fallthrough": 2,
    "no-func-assign": 2,
    "no-global-assign": 2,
    "no-implicit-coercion": 2,
    "no-implicit-globals": 2,
    "no-inner-declarations": 2,
    "no-invalid-regexp": 2,
    "no-invalid-this": 2,
    "no-irregular-whitespace": 2,
    "no-lonely-if": 2,
    "no-mixed-operators": 2,
    "no-mixed-spaces-and-tabs": 2,
    "no-multi-spaces": 2,
    "no-multi-str": 2,
    "no-multiple-empty-lines": [
      1,
      {
        "max": 1,
        "maxEOF": 0,
        "maxBOF": 0
      }
    ],
    "no-native-reassign": 2,
    "no-negated-in-lhs": 2,
    "no-new": 2,
    "no-new-func": 2,
    "no-new-wrappers": 2,
    "no-obj-calls": 2,
    "no-proto": 2,
    "no-prototype-builtins": 0,
    "no-redeclare": 2,
    "no-regex-spaces": 2,
    "no-restricted-imports": 2,
    "no-return-assign": 2,
    "no-self-assign": 2,
    "no-self-compare": 2,
    "no-sequences": 2,
    "no-shadow": 2,
    "no-shadow-restricted-names": 2,
    "no-spaced-func": 2,
    "no-sparse-arrays": 2,
    "no-this-before-super": 2,
    "no-throw-literal": 2,
    "no-undef": 2,
    "no-unexpected-multiline": 2,
    "no-unmodified-loop-condition": 2,
    "no-unreachable": 2,
    "no-unused-vars": [
      1,
      {
        "vars": "all",
        "args": "after-used"
      }
    ],
    "no-use-before-define": [
      2,
      {
        "functions": false
      }
    ],
    "no-useless-call": 2,
    "no-useless-computed-key": 2,
    "no-useless-concat": 2,
    "no-useless-rename": 2,
    "no-var": 2,
    "no-whitespace-before-property": 2,
    "object-curly-newline": 0,
    "object-curly-spacing": [
      2,
      "always"
    ],
    "object-property-newline": [
      2,
      {
        "allowMultiplePropertiesPerLine": true
      }
    ],
    "prefer-const": 2,
    "prefer-rest-params": 2,
    "prefer-spread": 2,
    "prefer-template": 2,
    "quotes": [
      2,
      "single",
      {
        "avoidEscape": true
      }
    ],
    "semi": [
      2,
      "always"
    ],
    "semi-spacing": 2,
    "space-before-blocks": 2,
    "space-before-function-paren": [
      2,
      {
        "anonymous": "never",
        "named": "never",
        "asyncArrow": "always"
      }
    ],
    "space-in-parens": [
      2,
      "never"
    ],
    "spaced-comment": [
      2,
      "always"
    ],
    "strict": 2,
    "valid-typeof": 2,
    "yoda": 2
  }
}

What did you do? Please include the actual source code causing the issue, as well as the command that you used to run ESLint.

const foo1 =
{
	bar : 123
};

What did you expect to happen?

ESLint should not complain. foo1 is an object with a single key but multiline, so it should accept the space before the colon. And it was this way before ESLint 6.7.0.

What actually happened? Please include the actual, raw output from ESLint.

 error    Extra space after key 'bar'                                   key-spacing

If I change it to:

const foo1 =
{
	bar: 123
};

then ESLint 6.7.0 does not complain, but 6.6.0 does complain.

[ibc]

In other words:

const foo1 =
{
	bar: 123
};

• In ESLint 6.6.0 foo1 is considered a multiLine object.
• In ESLint 6.7.0 foo1 is considered a singleLine object.

So key-spacing rules apply in a different way.

[ibc]

AFAIS this happens due this change.

[kaicataldo]

Thanks for reporting this. I agree that this looks like a regression. Will verify when I’m in front of my computer.

[ibc]

Confirmed that 6.7.1 fixes the issue. Well, AFAIS it's just a commit revert so it makes sense :)

[kaicataldo]

Thanks for the report!