Function measure_typescript 

pub fn measure_typescript(
    root: &Path,
    base: &str,
    thresholds: TypeScriptThresholds,
    exclude: &[String],
) -> Result<Outcome>

Diff-scoped TypeScript coverage floor (#162): the four vitest metrics measured over the <base>...HEAD changed .ts/.tsx/.mts/.cts lines instead of the whole tree. exclude is the coverage-rule exemptions, as in crate::coverage::measure_typescript — an excluded file is left out of the run, so its changed lines drop out of the ratios.

Scopes to TypeScript sources and returns early — with no coverage run — when the diff touches none, so a PR that changes only docs or other languages doesn’t pay for a measurement (and is vacuously covered). Requires vitest + git; an unresolvable base surfaces as an error rather than a silent pass.