Class: Rigor::Protection::TestSuiteOracle

Inherits:
Object
  • Object
show all
Defined in:
lib/rigor/protection/test_suite_oracle.rb

Overview

ADR-70 — the test-suite kill oracle, the dynamic sibling of DiagnosticOracle on the ADR-69 seam. A mutant is killed iff applying its bytes to the file under test turns the project’s test suite red. This is the dynamic half of the fused static∪dynamic protection map: a ‘Dynamic` site Rigor cannot bite (a type survivor) may still be fully guarded by a test.

The suite command is the **runner hook** (‘–test-command`, e.g. `bundle exec rake`). The runner is injectable so the decision logic is unit-testable without shelling out; the default shells out and reads the process exit status (0 = green / passed).

I/O policy: #killed? writes the mutant to disk, runs the suite, and **always restores** the original bytes in an ‘ensure` — a normal exception never leaves a mutant on disk. (A hard interrupt mid-suite is the standard mutation-testing hazard the `ensure` cannot cover; callers running this in CI accept that, as `mutant` / Stryker do.)

Instance Method Summary collapse

Constructor Details

#initialize(command:, runner: nil) ⇒ TestSuiteOracle

Returns a new instance of TestSuiteOracle.

Parameters:

  • command (Array<String>) —

    the test command (the runner hook)

  • runner (#call, nil) (defaults to: nil) —

    ‘runner.call(command) -> true iff the suite passed`. Defaults to shelling out via `system`.



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# File 'lib/rigor/protection/test_suite_oracle.rb', line 26

def initialize(command:, runner: nil)
  @command = command
  @runner = runner || method(:shell_run)
end

Instance Method Details

#green? ⇒ Boolean

The baseline: the suite must pass on clean code, else “a mutant survived” is meaningless (every mutant would look killed, or none would). Run once before measuring.

Returns:

  • (Boolean) 


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# File 'lib/rigor/protection/test_suite_oracle.rb', line 34

def green?
  @runner.call(@command)
end

#killed?(path:, original:, mutant_source:) ⇒ Boolean

Killed iff the mutant turns the suite red. Restores ‘original` afterward.

Parameters:

  • path (String) —

    the file to (temporarily) overwrite with the mutant

  • original (String) —

    the clean bytes to restore

  • mutant_source (String) —

    the mutated bytes to test against

Returns:

  • (Boolean) 


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# File 'lib/rigor/protection/test_suite_oracle.rb', line 42

def killed?(path:, original:, mutant_source:)
  File.write(path, mutant_source)
  !@runner.call(@command)
ensure
  File.write(path, original)
end