Mica::Testing::FuzzCampaign

Runs seeded fuzz cases through a format and tallies what happened.

The format's block parses one input and returns a Trial; anything the block raises is caught here. A case is:

• accepted when the block returns without an error,
• rejected when the trial carries a Mica::Error (the only acceptable failure),
• a crash when the block raises anything that is not a Mica::Error, or returns a trial with failed checks.

Every case is also checked for:

• budget overruns: operations above the allowance plus the format's check interval (the meter must stop work in time);
• determinism (when enabled): the same bytes give the same outcome twice.

campaign = Mica::Testing::FuzzCampaign.new(mutator, seed: 7_i64, overrun_slack: 70_000_i64)
report = campaign.run(10_000) do |bytes|
  meter = Mica::Core::WorkMeter.new
  begin
    Mica::XML.parse(bytes, meter: meter)
    Mica::Testing::FuzzCampaign::Trial.new("ok", nil, meter)
  rescue error : Mica::Error
    Mica::Testing::FuzzCampaign::Trial.new(error.message.to_s, error, meter)
  end
end
report.list_of_crashes # => [] of String