If/Else With Identical Branches

ID

javascript.if_identical_branches

Severity

low

Remediation Complexity

trivial

Remediation Risk

low

Remediation Effort

low

Resource

Reliability

Language

JavaScript

Tags

copy-paste, dead-code, reliability

Description

Reports an if/else where both branches have identical bodies:

if (cond) {
  doStuff();
} else {
  doStuff();
}

Rationale

A conditional that runs the same code on both sides almost always means one of two things, and both are bugs:

  • the else branch was copy-pasted from the if branch and the developer forgot to change it

  • the condition was meant to control a different statement and now does nothing

Either way the conditional is misleading. Readers expect that if/else means "two different things happen" — when both sides are identical, every reader has to take an extra moment to verify that observation.

Remediation

Drop the if/else if the condition has no side effects:

doStuff();

If the two branches were supposed to differ, fix whichever one is wrong:

if (cond) {
  doStuff();
} else {
  doOtherStuff();
}

Notes

The rule compares the textual content of the two branches after stripping the surrounding braces. It does not fire on else if chains — those are covered by javascript.duplicate_else_if_conditions. Empty branches are also not reported, since if (cond) {} may be a deliberate placeholder.

References