Duplicate Code
Copy-pasted blocks that should be extracted into utilities.
One of 104 modules in the GateTest scan suite. Catches the issue before it reaches code review, and on paid tiers opens a pull request with the fix already written.
Example finding from the duplicateCode module
16-line block duplicated 4x across src/handlers/
Why we catch it
The foundation. Catches the bugs every linter and compiler should have caught but didn't.
The Duplicate Code module sits in this category alongside 6 related modules. Together they form one of the layers of a GateTest scan — checks fire in parallel, findings cluster by root cause, and on paid tiers the AI auto-fix loop reads each finding, writes the fix, validates against the scanner, and opens a PR.
How GateTest covers duplicate code
- ✓Runs in every scan. Included on the Full ($99), Scan + Fix ($199), and Forensic Scan ($399) tiers. No additional configuration.
- ✓Free CLI.
npm i -g gatetest && gatetest --module duplicateCodeagainst any local repo. No paywall on the scanning itself. - ✓AI auto-fix PR. Scan + Fix tier opens a pull request with the fix, a regression test, and a pair-review by a second Claude. Forensic Scan tier adds per-finding diagnosis and cross-finding attack-chain correlation.
- ✓Honest confidence rating. Findings come with high / medium / low confidence so noisy patterns don't block the gate. The confidence-calibrator trainer reads customer suppressions and tightens rules over time.
Scan your repo for duplicate code
Free preview of the headline findings. Pay per scan — no subscription.
Frequently asked questions
What does the Duplicate Code module catch?
Copy-pasted blocks that should be extracted into utilities. Example finding: 16-line block duplicated 4x across src/handlers/
Does GateTest fix Duplicate Code issues automatically?
Yes — on the Scan + Fix tier ($199) and Forensic Scan tier ($399), Claude reads the finding, writes the fix, validates against the scanner, writes a regression test, and opens a pull request for your review.
Which tiers include the Duplicate Code module?
The Full tier ($99), Scan + Fix tier ($199), and Forensic Scan tier ($399) include all 104 modules including Duplicate Code. The Quick tier ($29) only includes 4 essential modules.
Can I run the Duplicate Code module from the CLI for free?
Yes — install with `npm i -g gatetest` and run `gatetest --module duplicateCode` against any local repository. Paid tiers add AI auto-fix and the cross-finding correlation work.