Add Rubocop check to avoid using `be_success`

Prevent using `be_success` call in controller specs to avoid
getting following deprecation warning:

```
DEPRECATION WARNING: The success? predicate is deprecated and
will be removed in Rails 6.0.
Please use successful? as provided by Rack::Response::Helpers.
```

1 files changed, 77 insertions, 0 deletions

diff --git a/spec/rubocop/cop/rspec/be_success_matcher_spec.rb b/spec/rubocop/cop/rspec/be_success_matcher_spec.rb
new file mode 100644
index 00000000000..fcb5791ef57
--- /dev/null
+++ b/spec/rubocop/cop/rspec/be_success_matcher_spec.rb
@@ -0,0 +1,77 @@
+require 'spec_helper'
+
+require 'rubocop'
+require 'rubocop/rspec/support'
+
+require_relative '../../../../rubocop/cop/rspec/be_success_matcher'
+
+describe RuboCop::Cop::RSpec::BeSuccessMatcher do
+  include CopHelper
+
+  OFFENSE_CALL_EXPECT_TO_BE_SUCCESS = %(expect(response).to be_success).freeze
+  OFFENSE_CALL_IS_EXPECTED_TO_BE_SUCCESS = %(is_expected.to be_success).freeze
+  CALL_EXPECT_TO_BE_SUCCESSFUL = %(expect(response).to be_successful).freeze
+  CALL_IS_EXPECTED_TO_BE_SUCCESSFUL = %(is_expected.to be_successful).freeze
+
+  let(:source_file) { 'spec/foo_spec.rb' }
+
+  subject(:cop) { described_class.new }
+
+  shared_examples 'an offensive be_success call' do |content|
+    it "registers an offense for `#{content}`" do
+      inspect_source(content, source_file)
+
+      expect(cop.offenses.size).to eq(1)
+      expect(cop.offenses.map(&:line)).to eq([1])
+      expect(cop.highlights).to eq([content])
+    end
+  end
+
+  context 'in a controller spec file' do
+    before do
+      allow(cop).to receive(:in_controller_spec?).and_return(true)
+    end
+
+    context "using expect(response).to be_success call" do
+      it_behaves_like 'an offensive be_success call', OFFENSE_CALL_EXPECT_TO_BE_SUCCESS
+    end
+
+    context "using is_expected.to be_success call" do
+      it_behaves_like 'an offensive be_success call', OFFENSE_CALL_IS_EXPECTED_TO_BE_SUCCESS
+    end
+
+    context "using expect(response).to be_successful" do
+      it "does not register an offense" do
+        inspect_source(CALL_EXPECT_TO_BE_SUCCESSFUL)
+
+        expect(cop.offenses.size).to eq(0)
+      end
+    end
+
+    context "using is_expected.to be_successful" do
+      it "does not register an offense" do
+        inspect_source(CALL_IS_EXPECTED_TO_BE_SUCCESSFUL)
+
+        expect(cop.offenses.size).to eq(0)
+      end
+    end
+  end
+
+  context 'outside of a controller spec file' do
+    context "using expect(response).to be_success call" do
+      it "does not register an offense" do
+        inspect_source(OFFENSE_CALL_EXPECT_TO_BE_SUCCESS)
+
+        expect(cop.offenses.size).to eq(0)
+      end
+    end
+
+    context "using is_expected.to be_success call" do
+      it "does not register an offense" do
+        inspect_source(OFFENSE_CALL_IS_EXPECTED_TO_BE_SUCCESS)
+
+        expect(cop.offenses.size).to eq(0)
+      end
+    end
+  end
+end