noYodaExpression

Diagnostic Category: lint/style/noYodaExpression

JavaScript (and super languages)

Since: v1.8.0

Sources:

Same as: yoda

Description

Disallow the use of yoda expressions.

A Yoda expression is a programming style where, given a binary operation, the “static” part of the binary operation is placed on the left-hand side. This rule forbids the use of Yoda expressions and enforces the placing of the “static” part of the binary operations on the right-hand side.

Exceptions

Range expressions like 0 < value && value < 1 or value <= 0 || 1 < value are allowed.

Examples

Invalid

if ("red" == value) {}

code-block.js:1:5 lint/style/noYodaExpression  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ Avoid the use of yoda expressions.
  
  > 1 │ if (“red” == value) {}
      │     ^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Yoda expressions can be confusing to some people, invert the expression operands for better readability.
  
  ℹ Safe fix: Flip the operators of the expression.
  
    1   │ - if·(“red”·==·value)·{}
      1 │ + if·(value·==·“red”)·{}
    2 2 │

if (true === value) {}

code-block.js:1:5 lint/style/noYodaExpression  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ Avoid the use of yoda expressions.
  
  > 1 │ if (true === value) {}
      │     ^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Yoda expressions can be confusing to some people, invert the expression operands for better readability.
  
  ℹ Safe fix: Flip the operators of the expression.
  
    1   │ - if·(true·===·value)·{}
      1 │ + if·(value·===·true)·{}
    2 2 │

if (5 != value) {}

code-block.js:1:5 lint/style/noYodaExpression  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ Avoid the use of yoda expressions.
  
  > 1 │ if (5 != value) {}
      │     ^^^^^^^^^^
    2 │ 
  
  ℹ Yoda expressions can be confusing to some people, invert the expression operands for better readability.
  
  ℹ Safe fix: Flip the operators of the expression.
  
    1   │ - if·(5·!=·value)·{}
      1 │ + if·(value·!=·5)·{}
    2 2 │

Valid

if (value === "red") {}

if (value === value) {}

if (value != 5) {}

if (0 < value && value < 1) {}

Resources

Wikipedia definition

How to configure

{
  "linter": {
    "rules": {
      "style": {
        "noYodaExpression": "error"
      }
    }
  }
}