I think this is a perfectly reasonable use case for shared examples. e.g. something like this:
shared_examples_for "attribute in collection" do |attr_name, valid_values|
context "with a valid role value" do
it "is valid" do
valid_values.each do |role|
build(:user, attr_name => role).should be_valid
end
end
end
context "with an empty #{attr_name}" do
subject { build(:user, attr_name => nil) }
it "is invalid" do
subject.should_not be_valid
end
it "adds an error message for the #{attr_name}" do
subject.save.should be_false
subject.errors.messages[attr_name].first.should == "can't be blank"
end
end
context "with an invalid #{attr_name} value" do
subject { build(:user, attr_name => 'unknown') }
it "is invalid" do
subject.should_not be_valid
end
it "adds an error message for the #{attr_name}" do
subject.save.should be_false
subject.errors.messages[attr_name].first.should =~ /unknown isn't a valid #{attr_name}/
end
end
end
Then you can call it in your specs like this:
describe "validation" do
describe "#role" do
behaves_like "attribute in collection", :role, User::ROLES
end
end
Haven't tested this but I think it should work.