no-extra-parens confilct with no-confusing-arrow

[tomfun]

ESLint - v2.9.0 (and 2.10.1 - see below)
parser - default
this code:

          set(val) {
            let result = val;
            if (_.isArray(val)) {
              result = _.map(val, (str) => /*THERE*/(_.isString(str) ? str.replace(/\(|\)|\-|\s/g, '') : str));
            }
            this.setDataValue(fieldName, JSON.stringify(result));
          }

-- give "no-extra-parens" error.

and this:

          set(val) {
            let result = val;
            if (_.isArray(val)) {
              result = _.map(val, /*THERE*/(str) => _.isString(str) ? str.replace(/\(|\)|\-|\s/g, '') : str);
            }
            this.setDataValue(fieldName, JSON.stringify(result));
          }

-- give "no-confusing-arrow" error

    "no-confusing-arrow": [
      2,
      {
        "allowParens": true
      }
    ],
    "no-extra-parens": [
      2,
      "all",
      {
        "conditionalAssign": true,
        "nestedBinaryExpressions": false
      }
    ],

-- part of configuration

I already have tried update ESlint to 2.10.1, and change configuration to:

    "no-extra-parens": [
      2,
      "all",
      {
        "conditionalAssign": false,
        "nestedBinaryExpressions": false,
        "returnAssign": false
      }
    ],

It did not help.
I expect, that "no extra parens" error would not appear in that case.

[nzakas]

Can you please use our issue template? https://github.com/eslint/eslint/blob/master/.github/ISSUE_TEMPLATE.md

[tomfun]

Tried to update issue, Is that good enough?

[nzakas]

That's better, in the future, please use the issue template.

I don't see a way to satisfy both rules right now. @eslint/eslint-team thoughts?

[platinumazure]

I would say we should enhance no-extra-parens to support allowing "extra" parens around a complex single-expression arrow function body. (no-confusing-arrow is being flagged here because the arrow could be a mistaken >= token which then makes sense in a conditional expression, so I assume the intent of no-confusing-arrow is to require parentheses to disambiguate.)

[alberto]

Isn't this solved by #5332 ?

[nzakas]

Good point. @tomfun can you try upgrading to the latest version and using the new option: http://eslint.org/docs/rules/no-confusing-arrow#options

[tomfun]

@nzakas I updated eslint, it doesn't help.

Of course I used old configuration:

"no-confusing-arrow": [
  2,
  {
    "allowParens": true
  }
],
"no-extra-parens": [
  2,
  "all",
  {
    "conditionalAssign": true,
    "nestedBinaryExpressions": false
  }
],

[tomfun]

@platinumazure It is all I want: add option to no-extra-parens
@nzakas So will you change label from question to something like extra feature?

[nzakas]

@platinumazure can you provide more details about what you are proposing? What qualifies as "complex"?

[tomfun]

"no-extra-parens": [
  2,
  "all",
  {
    "conditionalAssign": true,
    "nestedBinaryExpressions": false,
    "confusingArrow": true
  }
],

confusingArrow
And maybe add conflict details or when-not-to-use-it to docs

[MethodGrab]

I'm also experiencing this problem:

What version of ESLint are you using?
v3.0.1

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

Please show your full configuration:

/* eslint-env es6 */
/* eslint no-confusing-arrow: [ "error", { allowParens: true } ], "no-extra-parens": [ "error", "all", { conditionalAssign : false, returnAssign : false, nestedBinaryExpressions : false } ] */

What did you do? Please include the actual source code causing the issue.
Consider the following examples:

/* eslint-env es6 */
/* eslint no-confusing-arrow: [ "error", { allowParens: true } ], "no-extra-parens": [ "error", "all", { conditionalAssign : false, returnAssign : false, nestedBinaryExpressions : false } ] */

// this correctly warns about `no-extra-parens`
var a1 = ( 1 );

// this correctly warns about `no-confusing-arrow`
var b1 = x => x ? 1 : 2;

// Expected: this should be valid (as per http://eslint.org/docs/rules/no-confusing-arrow#options)
// Actual: it warns about `no-extra-parens`
var c1 = x => ( x ? 1 : 2 );

/* eslint-disable no-extra-parens */
// this now works fine, no warnings
var c2 = x => ( x ? 1 : 2 );
/* eslint-enable no-extra-parens */

What did you expect to happen?
The above test file should output 2 errors, for lines 5 & 8.
var c1 = x => ( x ? 1 : 2 ); should be valid with both no-confusing-arrow & no-extra-parens enabled.

What actually happened? Please include the actual, raw output from ESLint.
var c1 = x => ( x ? 1 : 2 ); triggered the no-extra-parens warning message.

~/dev/test-cases/eslint-conflict-6196/test.js
   5:10  error  Gratuitous parentheses around expression                       no-extra-parens
   8:10  error  Arrow function used ambiguously with a conditional expression  no-confusing-arrow
  12:15  error  Gratuitous parentheses around expression                       no-extra-parens

✖ 3 problems (3 errors, 0 warnings)

[kaicataldo]

@eslint/eslint-team Do we want to support this change? It's been a while since the last comment, but seems like we should at least discuss

[delijah]

I am also having troubles with those conflicting rules!

[alexander-akait]

@kaicataldo I am too having troubles with those conflicting rules! I love parenthesis around function argument and use ternary.

defer((config) => (config.exist ? 'exist' : 'not-exist'));

[kaicataldo]

I'm closing this issues because it looks like consensus couldn't be reached. While we wish we could accommodate all requests, we have limited resources and do need to prioritize. We've found that issues failing to reach consensus after 21 days tend to never reach consensus, and as a team have decided to close such issues. This doesn't mean the idea isn't interesting or valuable, only that it's not something the team can commit to at the moment.

[edoroshenko]

It's not wise to leave the problem without resolution. It could be solved later, priority could be decreased, but it should be solved eventually.
For now we had (as well as whoever has) to get rid of one of those rules. It's sad.

[alexander-akait]

@edoroshenko i can try resolve this issue today, have some time for this 😄

[edoroshenko]

@evilebottnawi would be awesome :)

[ghost]

PSA for people who stumble on this issue in the future - it was fixed. These may be the relevant parts of the configuration you are looking for:

"no-confusing-arrow": ["error", {"allowParens": true}],
"no-extra-parens": ["error", "all", {"enforceForArrowConditionals": false}],