guard-chain

consecutive single-line guards (if with a one statement body and no else) have no blank line between them

A guard is an if without else whose body is a single statement, braceless or in a block of exactly one statement. When two guards follow each other and both are compact (on one line, or braceless with a one line header and a one line body), the blank line between them goes. The body does not have to leave: if (dirty) count = 1; chains like if (!item) return;.

Only short-body outranks it. It outranks after-multiline, which is why the two braceless two line guards in the example sit together even though each spans two lines, and it outranks after-guard.

An if with an else is not a guard and breaks the chain. So does an if whose block holds two statements, and an if whose header spans lines. In the example the third if has a two statement block, so the blank line before it stays: that gap goes to after-multiline, because the guard above it spans two lines.

ExampleCopy Anchor Link

function accepts(entry: Entry, owner: string) {
  if (entry.owner !== owner)
    return false;

  if (entry.archived)
    return false;

  if (entry.size > limit) {
    log(entry);
    return false;
  }

  return true;
}

function accepts(entry: Entry, owner: string) {
  if (entry.owner !== owner)
    return false;
  if (entry.archived)
    return false;

  if (entry.size > limit) {
    log(entry);
    return false;
  }

  return true;
}