useSimplifiedLogicExpression

JavaScript (and super languages)

Summary

• Rule available since: v1.0.0
• Diagnostic Category: lint/complexity/useSimplifiedLogicExpression
• This rule has a safe fix.
• The default severity of this rule is information.

How to configure

biome.json

{
  "linter": {
    "rules": {
      "complexity": {
        "useSimplifiedLogicExpression": "error"
      }
    }
  }
}

Description

Discard redundant terms from logical expressions.

Examples

Invalid

const boolExp = true;
const r = true && boolExp;

code-block.js:2:11 lint/complexity/useSimplifiedLogicExpression  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Logical expression contains unnecessary complexity.
  
    1 │ const boolExp = true;
  > 2 │ const r = true && boolExp;
      │           ^^^^^^^^^^^^^^^
    3 │ 
  
  ℹ Safe fix: Discard redundant terms from the logical expression.
  
    2 │ const·r·=·true·&&·boolExp;
      │           --------        

const boolExp2 = true;
const r2 = boolExp || true;

code-block.js:2:12 lint/complexity/useSimplifiedLogicExpression  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Logical expression contains unnecessary complexity.
  
    1 │ const boolExp2 = true;
  > 2 │ const r2 = boolExp || true;
      │            ^^^^^^^^^^^^^^^
    3 │ 
  
  ℹ Safe fix: Discard redundant terms from the logical expression.
  
    2 │ const·r2·=·boolExp·||·true;
      │            -----------     

const nonNullExp = 123;
const r3 = null ?? nonNullExp;

code-block.js:2:12 lint/complexity/useSimplifiedLogicExpression  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Logical expression contains unnecessary complexity.
  
    1 │ const nonNullExp = 123;
  > 2 │ const r3 = null ?? nonNullExp;
      │            ^^^^^^^^^^^^^^^^^^
    3 │ 
  
  ℹ Safe fix: Discard redundant terms from the logical expression.
  
    2 │ const·r3·=·null·??·nonNullExp;
      │            --------           

const boolExpr1 = true;
const boolExpr2 = false;
const r4 = !boolExpr1 || !boolExpr2;

code-block.js:3:12 lint/complexity/useSimplifiedLogicExpression  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Logical expression contains unnecessary complexity.
  
    1 │ const boolExpr1 = true;
    2 │ const boolExpr2 = false;
  > 3 │ const r4 = !boolExpr1 || !boolExpr2;
      │            ^^^^^^^^^^^^^^^^^^^^^^^^
    4 │ 
  
  ℹ Safe fix: Reduce the complexity of the logical expression.
  
    1 1 │   const boolExpr1 = true;
    2 2 │   const boolExpr2 = false;
    3   │ - const·r4·=·!boolExpr1·||·!boolExpr2;
      3 │ + const·r4·=·!(boolExpr1·&&·boolExpr2);
    4 4 │   
  

Valid

const boolExpr3 = true;
const boolExpr4 = false;
const r5 = !(boolExpr1 && boolExpr2);
const boolExpr5 = true;
const boolExpr6 = false;

Related links

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