Refactor aliases_spec.rb to more closely adhere to the Let's Not school of RSpec (#1338)

Refactor aliases_spec.rb to more closely adhere to the Let's Not school of RSpec

spec/factory_bot/aliases_spec.rb

@@ -1,29 +1,28 @@
 describe FactoryBot, "aliases" do
-  context "aliases for an attribute" do
-    subject { FactoryBot.aliases_for(:test) }
-    it      { should include(:test) }
-    it      { should include(:test_id) }
+  it "for an attribute should include the original attribute and a version suffixed with '_id'" do
+    aliases = FactoryBot.aliases_for(:test)
+
+    expect(aliases).to include(:test, :test_id)
   end
 
-  context "aliases for a foreign key" do
-    subject { FactoryBot.aliases_for(:test_id) }
-    it      { should include(:test) }
-    it      { should include(:test_id) }
+  it "for a foreign key should include both the suffixed and un-suffixed variants" do
+    aliases = FactoryBot.aliases_for(:test_id)
+
+    expect(aliases).to include(:test, :test_id)
   end
 
-  context "aliases for an attribute starting with an underscore" do
-    subject { FactoryBot.aliases_for(:_id) }
-    it      { should_not include(:id) }
+  it "for an attribute which starts with an underscore should not include a non-underscored version" do
+    aliases = FactoryBot.aliases_for(:_id)
+
+    expect(aliases).not_to include(:id)
   end
 end
 
 describe FactoryBot, "after defining an alias" do
-  before do
+  it "the list of aliases should include a variant with no suffix at all, and one with an '_id' suffix" do
     FactoryBot.aliases << [/(.*)_suffix/, '\1']
+    aliases = FactoryBot.aliases_for(:test_suffix)
+
+    expect(aliases).to include(:test, :test_suffix_id)
   end
-
-  subject { FactoryBot.aliases_for(:test_suffix) }
-
-  it { should include(:test) }
-  it { should include(:test_suffix_id) }
 end