butcher_report

The Stryker mutation-report schema, split out of the butcher mutation engine so a consumer can read or write the report without taking the engine.

Stryker's JSON report is butcher's primary output format, which makes its shape a contract rather than an implementation detail: a dashboard or a CI gate should be able to parse it without depending on the tool that produced it.

What is here

Every type of the draft-07 MutationTestResult schema, at all four nesting levels, with its required fields enforced on parse and its optional fields omitted — never written as null — on emit. MutantStatus carries all eight wire spellings, including Pending, which butcher never emits but another producer may.

import 'dart:convert';
import 'dart:io';

import 'package:butcher_report/butcher_report.dart';

void main() {
  final report = parseMutationTestReport(
    File('reports/mutation.json').readAsStringSync(),
  );
  final survived = <ReportMutant>[
    for (final file in report.files.values)
      for (final mutant in file.mutants)
        if (mutant.status == MutantStatus.survived) mutant,
  ];
  print('${survived.length} mutants survived');

  File('reports/copy.json').writeAsStringSync(jsonEncode(report.toJson()));
}

The package itself does no file and no network I/O: the two entry points take a JSON string or an already-decoded map, and toJson returns a map. Opening the files above is the caller's job, as the example shows. Every type compares by value, hand-written, so a CLI toolchain takes no code-generation dependency to use them.

test/fixtures/mutation-testing-report-schema.json is a verbatim copy of the published schema, and the suite checks the models against it rather than against prose.

License

MIT, derived from the upstream radioactive_dart package — see LICENSE.