Make it possible to define global scenario attributes

qa/.gitignore

 tmp/
+.ruby-version

qa/bin/qa

@@ -4,4 +4,4 @@ require_relative '../qa'
 QA::Scenario
   .const_get(ARGV.shift)
-  .perform(*ARGV)
+  .launch!(*ARGV)

qa/qa.rb

@@ -18,6 +18,7 @@ module QA
     ##
     # Support files
     #
+    autoload :Bootable, 'qa/scenario/bootable'
     autoload :Actable, 'qa/scenario/actable'
     autoload :Entrypoint, 'qa/scenario/entrypoint'
     autoload :Template, 'qa/scenario/template'

qa/qa/page/mattermost/login.rb

@@ -3,7 +3,7 @@ module QA
     module Mattermost
       class Login < Page::Base
         def initialize
-          visit(Runtime::Scenario.mattermost + '/login')
+          visit(Runtime::Scenario.mattermost_address + '/login')
         end
         def sign_in_using_oauth

qa/qa/page/mattermost/main.rb

@@ -3,7 +3,7 @@ module QA
     module Mattermost
       class Main < Page::Base
         def initialize
-          visit(Runtime::Scenario.mattermost)
+          visit(Runtime::Scenario.mattermost_address)
         end
       end
     end

qa/qa/runtime/scenario.rb

 module QA
   module Runtime
+    ##
+    # Singleton approach to global test scenario arguments.
+    #
     module Scenario
       extend self
-      attr_accessor :mattermost
+
+      attr_reader :attributes
+
+      def define(attribute, value)
+        (@attributes ||= {}).store(attribute.to_sym, value)
+
+        define_singleton_method(attribute) do
+          @attributes[attribute.to_sym].tap do |value|
+            if value.to_s.empty?
+              raise ArgumentError, "Empty `#{attribute}` attribute!"
+            end
+          end
+        end
+      end
+
+      def method_missing(name, *)
+        raise ArgumentError, "Scenario attribute `#{name}` not defined!"
+      end
     end
   end
 end

qa/qa/scenario/bootable.rb

+require 'optparse'
+
+module QA
+  module Scenario
+    module Bootable
+      Option = Struct.new(:name, :arg, :desc)
+
+      def self.included(base)
+        base.extend(ClassMethods)
+      end
+
+      module ClassMethods
+        def launch!(argv)
+          arguments = OptionParser.new do |parser|
+            options.to_a.each do |opt|
+              parser.on(opt.arg, opt.desc) do |value|
+                Runtime::Scenario.define(opt.name, value)
+              end
+            end
+          end
+
+          arguments.parse!(argv)
+
+          if has_attributes?
+            self.perform(**Runtime::Scenario.attributes)
+          else
+            self.perform(*argv)
+          end
+        end
+
+        private
+
+        def attribute(name, arg, desc)
+          options.push(Option.new(name, arg, desc))
+        end
+
+        def options
+          @options ||= []
+        end
+
+        def has_attributes?
+          options.any?
+        end
+      end
+    end
+  end
+end

qa/qa/scenario/entrypoint.rb

@@ -5,6 +5,8 @@ module QA
     # including staging and on-premises installation.
     #
     class Entrypoint < Template
+      include Bootable
+
       def self.tags(*tags)
         @tags = tags
       end

qa/qa/scenario/test/integration/mattermost.rb

@@ -10,7 +10,8 @@ module QA
           tags :core, :mattermost
           def perform(address, mattermost, *files)
-            Runtime::Scenario.mattermost = mattermost
+            Runtime::Scenario.define(:mattermost_address, mattermost)
+
             super(address, *files)
           end
         end

qa/spec/runtime/scenario_spec.rb

+describe QA::Runtime::Scenario do
+  subject do
+    Module.new.extend(described_class)
+  end
+
+  it 'makes it possible to define global scenario attributes' do
+    subject.define(:my_attribute, 'some-value')
+    subject.define(:another_attribute, 'another-value')
+
+    expect(subject.my_attribute).to eq 'some-value'
+    expect(subject.another_attribute).to eq 'another-value'
+    expect(subject.attributes)
+      .to eq(my_attribute: 'some-value', another_attribute: 'another-value')
+  end
+
+  it 'raises error when attribute is not known' do
+    expect { subject.invalid_accessor }
+      .to raise_error ArgumentError, /invalid_accessor/
+  end
+
+  it 'raises error when attribute is empty' do
+    subject.define(:empty_attribute, '')
+
+    expect { subject.empty_attribute }
+      .to raise_error ArgumentError, /empty_attribute/
+  end
+end

qa/spec/scenario/bootable_spec.rb

+describe QA::Scenario::Bootable do
+  subject do
+    Class.new(QA::Scenario::Template)
+      .include(described_class)
+  end
+
+  it 'makes it possible to define the scenario attribute' do
+    subject.class_eval do
+      attribute :something, '--something SOMETHING', 'Some attribute'
+      attribute :another, '--another ANOTHER', 'Some other attribute'
+    end
+
+    expect(subject).to receive(:perform)
+      .with(something: 'test', another: 'other')
+
+    subject.launch!(%w[--another other --something test])
+  end
+
+  it 'does not require attributes to be defined' do
+    expect(subject).to receive(:perform).with('some', 'argv')
+
+    subject.launch!(%w[some argv])
+  end
+end