Sample coverage config lets one of the four CI gates pass without new coverage

Coverage and assertion are different measurements, and the post makes that distinction itself before its config blurs it. In the coverage step it warns that AI can generate tests which execute code without asserting meaningful behavior ^[7]. The filter it then prescribes for that failure is a Jest coverageThreshold of 80 for branches, functions, lines and statements ^[5], on the reasoning that a test which does not meaningfully increase coverage is probably asserting on trivial or hallucinated paths ^[6]. A test that calls a function and checks nothing still records every line it touched. The threshold is also global. A repository sitting at 85 percent statements clears an 80 percent floor even when a new generated test covers nothing new ^[15].

The gate that can see an empty assertion is the mutation gate, and the post is right to call mutation testing the strongest guard against hallucinated assertions ^[8]. Its example .strykerrc.json sets thresholdHigh to 80, thresholdLow to 60 and thresholdBreak to 0 ^[9]. The pipeline then runs that job as `npx stryker run` and says a PR merges only when all gates pass ^[10]. Whether the job can fail a build at all is a question about the break threshold, and the sample value is 0. Read Stryker's documentation on that field before copying the file.

The drift gate is a snapshot. The example calls userService.getActiveUsers, matches the result with toMatchSnapshot, and fails CI on any change until a developer explicitly approves the diff ^[13]. A snapshot records whatever the code did on the day it was taken. If the generated test captured a bug, the approved snapshot then defends the bug. "Review generated code, but don't trust it. Gates replace manual review for correctness," the post says ^[14].

Its tip list also says to fail fast, running execution and coverage before mutation to save time ^[11]. The pipeline it prints runs execution, coverage and mutation as three parallel jobs, each checking out the repository and installing dependencies before it starts ^[12][10].

None of this argues against the design. Treating generated tests as untrusted input is the right default in a repo where the code arrives faster than anyone can review it ^[1], and the execution gate costs a checkout, an install and one npm test ^[3]. "If a test doesn't run, it provides zero protection," the post says ^[4]. It does not report results from running the gates on a real codebase, so there is no hallucination rate in it to size your own suite against ^[17]. What transfers is the pipeline shape. The coverage scope and the break threshold are set by whoever copies it, and in the samples they are global and 0 ^[5][9].