@canyonjs/report

An Istanbul reporter that emits the Canyon interactive HTML coverage report. It extends istanbul-lib-report’s ReportBase, aggregates per-file coverage, enriches it with optional Git diff metadata, and writes a self-contained site (from @canyonjs/report-html) plus compressed report-data.js for the UI.

Features

• Rich HTML report — Copies the bundled @canyonjs/report-html assets into the output directory and generates data/report-data.js with gzip-compressed coverage payload.
• Diff-aware metrics — If you supply a unified diff (see below), the report can align coverage with changed lines and surface changed-line / “new lines” style summaries (via canyon-data).
• canyon.json — When applicable, writes newlinesPercent next to index.html for downstream tooling.

Installation

npm install @canyonjs/report @canyonjs/report-html

@canyonjs/report-html is a runtime dependency: the reporter resolves its dist folder and copies it into your coverage output directory.

Usage

Register @canyonjs/report as an Istanbul reporter wherever your toolchain exposes Istanbul-compatible reporters (Vitest, nyc, Jest, c8, etc.).

Vitest

// vitest.config.ts
export default {
  test: {
    coverage: {
      provider: "istanbul",
      reporter: ["json", "@canyonjs/report"],
    },
  },
};

nyc

{
  "reporter": ["json", "@canyonjs/report"]
}

Or CLI: nyc --reporter=@canyonjs/report …

Jest / c8

Use each tool’s coverageReporters (or equivalent) and include "@canyonjs/report" alongside "json" if you still need raw JSON output.

Optional: diff input

To correlate coverage with a patch, pass unified diff text via reporter options (when supported) or place a diff.txt file in the current working directory when the reporter runs. If no inline diff is configured, the reporter tries to read ./diff.txt automatically.

The diff is parsed with parse-diff to map additions/deletions per file.

Output layout

Typical output directory (e.g. coverage/):

• index.html — Entry for the Canyon report UI
• data/report-data.js — window.reportData payload (compressed)
• canyon.json — Optional; includes newlinesPercent when computed
• Additional assets copied from @canyonjs/report-html/dist

The console logs the resolved report path when generation finishes.

Development

pnpm install
pnpm run build
pnpm test

License

MIT — see the repository for details.