Clip LeetCode: A Malformed-Route Repair Candidate

Self-built userscript robustness study. Synthetic tests, not client work.

Clip LeetCode v3.0.0 parses problem and contest URLs as navigation changes. In source-level tests, malformed percent escapes in a matched problem or contest slug caused the parser to throw URIError: URI malformed. The exception could prevent a route-change event for that navigation. Ordinary LeetCode URLs were not shown to fail, and no live-site or customer impact was observed.

The original installable script was preserved and identified by its Git blob. The new Node test suite extracts the actual parser, route watcher, and their supporting declarations from the selected source file. It uses synthetic window, history, and navigation events rather than a second implementation of the route logic.

The 22 cases cover normal problem and contest paths, valid Unicode, unsupported paths, invalid URLs, malformed matched segments, navigation signals, duplicate suppression, cleanup, restart, and recovery after a malformed route.

A narrow change catches decoding errors in the matched route segments and returns a null route context. Valid routes keep their existing behavior. Malformed text in unrelated trailing segments, query strings, and fragments retains its prior behavior.

Original v3.0.0 source: 17 tests passed, 5 failed.

Local repair candidate: 22 tests passed, 0 failed.

Candidate JavaScript syntax check: passed.

Patch-application check against the preserved original: passed.

The five original failures comprise four malformed-slug parser cases and one route-watcher regression case. These numbers describe this 22-case synthetic suite, not the script's overall reliability or coverage.

The candidate is unpublished and is not a release. The public repository still contains the original implementation. The full userscript, real browser navigation, userscript-manager installation, DOM behavior, and clipboard behavior were not verified. No production compatibility, client outcome, or revenue is claimed.

The next technical gate is an installed-manager check of normal navigation, malformed-route handling, unsupported-route cleanup, and return to a valid problem before any release decision.

This study illustrates the approach behind a bounded userscript repair: reproduce one agreed failure, make a narrow change, and record both regression results and remaining verification limits.

Repair or customize one userscript: a USD 100 inquiry-first pilot. Message before ordering so scope, test access, acceptance cases, delivery date, and payment readiness can be confirmed.