Function measure_typescript 

pub fn measure_typescript(
    root: &Path,
    exempt: &[String],
    exempt_lines: &BTreeMap<String, BTreeSet<u32>>,
    base: Option<&str>,
) -> Result<Vec<Survivor>>

Run Stryker over the TypeScript project at root and return its un-exempted survivors — the TS arm of the mutation rule (#202), parity with measure_rust.

With base set, only mutants on the <base>...HEAD changed lines are tested — Stryker has no native git-diff mode, so the changed lines become --mutate <file>:<line>-<line> ranges (line granularity, matching cargo-mutants’ --in-diff). Without it, the project’s configured mutate set runs. exempt is the file-level exempt paths and exempt_lines the line-scoped ones (#226). Stryker must be installed / resolvable.