Added specs for SystemCheck and custom matcher

lib/system_check.rb

@@ -15,9 +15,16 @@ module SystemCheck
       raise ArgumentError, 'Invalid executor'
     end
 
+    prepare(component, checks, executor_klass).execute
+  end
+
+  def self.prepare(component, checks = [], executor_klass = SimpleExecutor)
     executor = executor_klass.new(component)
     checks.each do |check|
       executor << check
     end
+
+    executor
   end
+  private_class_method :prepare
 end

spec/lib/system_check_spec.rb

+require 'spec_helper'
+
+describe SystemCheck, lib: true do
+  subject { SystemCheck }
+
+  describe '.run' do
+    it 'requires custom executor to be a BasicExecutor' do
+      expect { subject.run('Component', [], SystemCheck::SimpleExecutor) }.not_to raise_error
+    end
+
+    context 'custom matcher' do
+      class SimpleCheck < SystemCheck::BaseCheck
+        def check?
+          true
+        end
+      end
+
+      class OtherCheck < SystemCheck::BaseCheck
+        def check?
+          false
+        end
+      end
+
+      subject { SystemCheck }
+
+      it 'detects execution of SimpleCheck' do
+        is_expected.to execute_check(SimpleCheck)
+
+        SystemCheck.run('Test', [SimpleCheck])
+      end
+
+      it 'detects exclusion of OtherCheck in execution' do
+        is_expected.not_to execute_check(OtherCheck)
+
+        SystemCheck.run('Test', [SimpleCheck])
+      end
+    end
+  end
+end

spec/support/matchers/execute_check.rb

+RSpec::Matchers.define :execute_check do |expected|
+  match do |actual|
+    expect(actual).to eq(SystemCheck)
+    expect(actual).to receive(:run) do |*args|
+      expect(args[1]).to include(expected)
+    end
+  end
+
+  match_when_negated do |actual|
+    expect(actual).to eq(SystemCheck)
+    expect(actual).to receive(:run) do |*args|
+      expect(args[1]).not_to include(expected)
+    end
+  end
+
+  failure_message do |actual|
+    return 'This matcher must be used with SystemCheck' unless actual == SystemCheck
+  end
+end