noNestedTernary

JavaScript (and super languages)

Summary

• Rule available since: v1.9.3
• Diagnostic Category: lint/style/noNestedTernary
• This rule doesn’t have a fix.
• The default severity of this rule is information.
• Sources:
  • Same as no-nested-ternary

How to configure

biome.json

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

Description

Disallow nested ternary expressions.

Nesting ternary expressions can make code more difficult to understand.

Examples

Invalid

const thing = foo ? bar : baz === qux ? quxx : foobar;

code-block.js:1:27 lint/style/noNestedTernary ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Do not nest ternary expressions.
  
  > 1 │ const thing = foo ? bar : baz === qux ? quxx : foobar;
      │                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Nesting ternary expressions can make code more difficult to understand.
  
  ℹ Convert nested ternary expression into if-else statements or separate the conditions to make the logic easier to understand.
  

foo ? baz === qux ? quxx() : foobar() : bar();

code-block.js:1:7 lint/style/noNestedTernary ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Do not nest ternary expressions.
  
  > 1 │ foo ? baz === qux ? quxx() : foobar() : bar();
      │       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Nesting ternary expressions can make code more difficult to understand.
  
  ℹ Convert nested ternary expression into if-else statements or separate the conditions to make the logic easier to understand.
  

Valid

const thing = foo ? bar : foobar;

let thing;

if (foo) {
    thing = bar;
} else if (baz === qux) {
    thing = quxx;
} else {
    thing = foobar;
}

Related links

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