class RSpec::Core::Bisect::ForkRunner

A Bisect runner that runs requested subsets of the suite by forking sub-processes. The main process bootstraps RSpec and the application environment (including preloading files specified via ‘–require`) so that the individual spec runs do not have to re-pay that cost. Each spec run happens in a forked process, ensuring that the spec files are not loaded in the main process.

For most projects, bisections that use ‘ForkRunner` instead of `ShellRunner` will finish significantly faster, because the `ShellRunner` pays the cost of booting RSpec and the app environment on every run of a subset. In contrast, `ForkRunner` pays that cost only once.

However, not all projects can use ‘ForkRunner`. Obviously, on platforms that do not support forking (e.g. Windows), it cannot be used. In addition, it can cause problems for some projects that put side-effectful spec bootstrapping logic that should run on every spec run directly at the top level in a file loaded by `–require`, rather than in a `before(:suite)` hook. For example, consider a project that relies on some top-level logic in `spec_helper` to boot a Redis server for the test suite, intending the Redis bootstrapping to happen on every spec run. With `ShellRunner`, the bootstrapping logic will happen for each run of any subset of the suite, but for `ForkRunner`, such logic will only get run once, when the `RunDispatcher` boots the application environment. This might cause problems. The solution is for users to move the bootstrapping logic into a `before(:suite)` hook, or use the slower `ShellRunner`.

@private

# File rspec-core/lib/rspec/core/bisect/fork_runner.rb, line 43
def self.name
  :fork
end

# File rspec-core/lib/rspec/core/bisect/fork_runner.rb, line 47
def initialize(shell_command, spec_runner)
  @shell_command = shell_command
  @channel = Channel.new
  @run_dispatcher = RunDispatcher.new(spec_runner, @channel)
end

# File rspec-core/lib/rspec/core/bisect/fork_runner.rb, line 36
def self.start(shell_command, spec_runner)
  instance = new(shell_command, spec_runner)
  yield instance
ensure
  instance.shutdown
end

# File rspec-core/lib/rspec/core/bisect/fork_runner.rb, line 58
def original_results
  @original_results ||= dispatch_run(ExampleSetDescriptor.new(
    @shell_command.original_locations, []))
end

# File rspec-core/lib/rspec/core/bisect/fork_runner.rb, line 53
def run(locations)
  run_descriptor = ExampleSetDescriptor.new(locations, original_results.failed_example_ids)
  dispatch_run(run_descriptor)
end

# File rspec-core/lib/rspec/core/bisect/fork_runner.rb, line 63
def shutdown
  @channel.close
end