no-arrow-condition
Disallows arrow functions where test conditions are expected.
Arrow functions (=>) are similar in syntax to some comparison operators (>, <, <=, and >=). This rule warns against using the arrow function syntax in places where a condition is expected. Even if the arguments of the arrow function are wrapped with parens, this rule still warns about it.
Here’s an example where the usage of => is most likely a typo:
// This is probably a typo
if (a => 1) {}
// And should instead be
if (a >= 1) {}
There are also cases where the usage of => can be ambiguous and should be rewritten to more clearly show the author’s intent:
// The intent is not clear
var x = a => 1 ? 2 : 3
// Did the author mean this
var x = function (a) { return a >= 1 ? 2 : 3 }
// Or this
var x = a <= 1 ? 2 : 3
Rule Details
Examples of incorrect code for this rule:
/*eslint no-arrow-condition: "error"*/
/*eslint-env es6*/
if (a => 1) {}
while (a => 1) {}
for (var a = 1; a => 10; a++) {}
a => 1 ? 2 : 3
(a => 1) ? 2 : 3
var x = a => 1 ? 2 : 3
var x = (a) => 1 ? 2 : 3
Related Rules
Version
This rule was introduced in ESLint v1.8.0 and removed in v2.0.0-beta.3.