Version 1.10 Beats Version 1.9 — JavaScript Bug Hunt

Briefing

Inspired by every auto-updater that ever refused to update: comparing version strings as strings makes "1.10.0" sort before "1.9.0", so half the fleet stays on the old release forever.

semver.js — compare numerically, segment by segment.

Bug report

BUG-VERCMP · Priority: High · Reported by: release eng

isNewer(a, b) — true iff version a is strictly newer than b:

• compare dot-separated segments numerically
• missing segments count as 0 ("2.0" == "2.0.0")

Observed: "1.10.0" is treated as OLDER than "1.9.0"; the updater loops.

Logs

[updater] latest=1.10.0 current=1.9.0 -> "already up to date"

The code as shipped

src/release/semver.js (editable)

// Version comparison for the auto-updater.
exports.isNewer = function (a, b) {
  return a > b;
};