dart_mutant 0.2.1

Mutation testing for Dart and Flutter. Mutants are made from the syntax tree and from resolved types, and the ones that cannot compile are found before a test is run.

example/README.md

Example

A small package to try dart_mutant on: one function, and tests that leave two of its decisions unchecked.

dart pub global activate dart_mutant

cd example
dart pub get
dart_mutant run lib/discount.dart

  lib/discount.dart: 18 of 22 mutant(s) with "dart test --fail-fast --timeout 10s test/discount_test.dart", 3 at a time (4 do not compile)
  lib/discount.dart: 22 mutants / killed 16 / survived 2 / timeout 0 / compile error 4 (4 found before the run) (10.0s)
dart_mutant run: 2 surviving mutant(s)
  - lib/discount.dart:7:30 / NumberLiteral / 0 → 1 (Survived)
  - lib/discount.dart:8:39 / MethodExpression / round → ceil (Survived)
dart_mutant run: FAILED (22 mutants / killed 16 / survived 2 / timeout 0 / compile error 4 (4 found before the run))

(, 3 at a time is what a machine with 12 processors says; see --jobs.)

• 0 → 1 in percent.clamp(0, 100): no test has a percentage below zero.
• round → ceil: no test has a price that rounds down.
• The four mutants that do not compile are the syntax mutants of if (cents == null): the line after it multiplies cents. GuardAlwaysTaken and GuardThrows test the same guard in a form that compiles, and both are killed.

Add expect(discounted(1000, -5), 1000); and expect(discounted(333, 60), 133); to test/discount_test.dart, and the run passes.

The same run with the tests named in a plan file (plan.json):

dart_mutant run --plan plan.json

The report is in reports/mutation/mutation.json. For a page that shows it in a browser, with every mutant at its place in the source:

dart_mutant run lib/discount.dart --html reports/mutation/mutation.html