nestedStandaloneIfs

Reports if statements that are the only statement inside an else block or inside another if without an else.

✅ This rule is included in the ts stylistic and stylisticStrict presets.

This rule identifies two patterns of unnecessarily nested if statements that can be simplified:

Lonely if in else: An if statement that is the only statement inside an else block can be written as else if.
Lonely if in if: An if statement that is the only statement inside another if (without an else) can have its conditions combined with &&.

Both patterns reduce nesting and improve code readability.

Note that this rule will not flag cases where:

There are comments inside the block (indicating intentional structure)
Multiple statements exist in the block
The outer if has an else clause (for the “lonely if in if” pattern)

Examples

if (condition) {
  doSomething();
} else {
  if (otherCondition) {
    doSomethingElse();
  }
}

if (condition) {
  doSomething();
} else if (otherCondition) {
  doSomethingElse();
}

Lonely `if` in `if`

❌ Incorrect
✅ Correct

if (a) {
  if (b) {
    doSomething();
  }
}

if (a && b) {
  doSomething();
}

Operator Precedence

When combining conditions, the rule correctly handles operator precedence by adding parentheses where needed:

❌ Incorrect
✅ Correct

if (a || b) {
  if (c) {
    doSomething();
  }
}

if ((a || b) && c) {
  doSomething();
}

When Not To Use It

If you prefer explicit nesting for clarity in complex conditional logic, or if your codebase has a style guide that prefers the nested form, you may want to disable this rule.

Equivalents in Other Linters

Made with ❤️‍🔥 in Boston by Josh Goldberg and contributors.