Add rspec/rails integration

.rubocop.yml

@@ -6,6 +6,7 @@ AllCops:
   Exclude:
     - 'bin/*'
     - 'vendor/bundle/**/*'
+    - 'spec/fixtures/**/*'
   NewCops: enable
   SuggestExtensions: false
 
@@ -142,3 +143,4 @@ RSpec/SpecFilePathFormat:
     RuboCop: rubocop
     RSpec: rspec
     SimpleCov: simplecov
+    RSpecFormatterSkipOnFailure: rspec_formatter_skip_on_failure

lib/simplecov/inline.rb

@@ -1,5 +1,7 @@
 require_relative 'inline/version'
 require_relative 'inline/formatter'
+require_relative 'inline/rspec_formatter_skip_on_failure'
+require_relative 'inline/integration'
 
 module SimpleCov
   module Inline

lib/simplecov/inline/formatter.rb

@@ -1,6 +1,6 @@
 require 'rainbow'
 
-module Simplecov
+module SimpleCov
   module Inline
     class Formatter
       Result = Struct.new(:file, :start_line, :end_line, :type) do

lib/simplecov/inline/integration.rb

@@ -0,0 +1,61 @@
+module SimpleCov
+  module Inline
+    class Integration
+      class << self
+        def configure_rspec_rails(rspec: RSpec, rails: Rails)
+          rspec.configure do |rspec_config|
+            rspec_config.add_formatter SimpleCov::Inline::RSpecFormatterSkipOnFailure
+            rspec_config.before(:suite) do
+              SimpleCov::Inline::Integration.configure_formatter(rspec_config:, rails_root: rails.root.to_s)
+            end
+          end
+        end
+
+        def configure_formatter(rspec_config:, rails_root:)
+          # Restrict coverage reporting to spec files and the file they are testing.
+          # Note files_to_run contains all spec files when running rspec with no args,
+          # so in that case do not filter.
+          # To do so would exclude files that are covered but not directly tested.
+          return if running_all_specs?(rspec_config:, rails_root:)
+
+          SimpleCov::Inline::Formatter.config do |coverage_config|
+            if rspec_config.inclusion_filter.rules.key?(:locations)
+              # Skip coverage output if running rspec against a single line.
+              # e.g. spec/x_spec.rb:123
+              coverage_config.no_output!(reason: 'filtered to line of code')
+            else
+              coverage_config.files = rspec_config.files_to_run.flat_map do |spec_path|
+                [spec_path, rails_path_under_test(spec_path:, rails_root:)]
+              end.compact
+            end
+          end
+        end
+
+        private
+
+        def running_all_specs?(rspec_config:, rails_root:)
+          Dir.glob("#{rails_root}#{rspec_config.pattern}").to_set == rspec_config.files_to_run.to_set
+        end
+
+        def rails_path_under_test(spec_path:, rails_root:)
+          # Mappings
+          # /app/spec/lib/x_spec.rb -> /app/lib/x.rb
+          # /app/spec/controller/y_spec.rb -> /app/app/controllers/y.rb
+          raise 'Spec file must be in rails root.' unless spec_path.start_with?(rails_root)
+
+          _spec_root, spec_type, *other_directories, filename = spec_path[(rails_root.length + 1)..].split('/')
+
+          return if filename.nil?
+
+          filename_under_test = filename.gsub(/_spec.rb$/, '.rb')
+
+          if spec_type == 'lib'
+            [rails_root, spec_type, *other_directories, filename_under_test]
+          else
+            [rails_root, 'app', spec_type, *other_directories, filename_under_test]
+          end.compact.join('/')
+        end
+      end
+    end
+  end
+end

lib/simplecov/inline/rspec_formatter_skip_on_failure.rb

@@ -0,0 +1,28 @@
+module SimpleCov
+  module Inline
+    class RSpecFormatterSkipOnFailure
+      RSpec::Core::Formatters.register self, :dump_failures
+
+      def initialize(output)
+        @output = output
+      end
+
+      def dump_failures(notification)
+        return unless skip_reason(notification:)
+
+        SimpleCov::Inline::Formatter.config do |coverage_config|
+          coverage_config.no_output!(reason: skip_reason(notification:))
+        end
+      end
+
+      private
+
+      def skip_reason(notification:)
+        return 'no examples were run' if notification.examples.none?
+        return 'some specs failed' if notification.failed_examples.any?
+
+        nil
+      end
+    end
+  end
+end

spec/lib/simplecov/inline/formatter_spec.rb

@@ -1,4 +1,4 @@
-RSpec.describe Simplecov::Inline::Formatter do
+RSpec.describe SimpleCov::Inline::Formatter do
   after { described_class.reset_config }
 
   describe '#format' do

spec/lib/simplecov/inline/integration_spec.rb

@@ -0,0 +1,131 @@
+RSpec.describe SimpleCov::Inline::Integration do
+  after { SimpleCov::Inline::Formatter.reset_config }
+
+  describe '#configure_rspec_rails' do
+    subject { described_class.configure_rspec_rails(rspec:, rails:) }
+
+    let(:rspec) { class_double(RSpec) }
+    let(:rspec_config) { instance_double(RSpec::Core::Configuration) }
+
+    let(:rails) { double('Rails', root: :fake_root) } # rubocop:todo RSpec/VerifiedDoubles
+
+    before do
+      allow(rspec).to receive(:configure).and_yield(rspec_config)
+      allow(rspec_config).to receive(:add_formatter)
+      allow(rspec_config).to receive(:before)
+      allow(described_class).to receive(:configure_formatter)
+    end
+
+    it 'adds a formatter to the rspec config', :aggregate_failures do
+      subject
+
+      expect(rspec_config).to have_received(:add_formatter).with(SimpleCov::Inline::RSpecFormatterSkipOnFailure)
+    end
+
+    it 'adds a before suite hook that calls configure_formatter', :aggregate_failures do
+      subject
+
+      expect(rspec_config).to have_received(:before).with(:suite) do |&block|
+        block.call
+      end
+
+      expect(described_class).to have_received(:configure_formatter).with(rspec_config:, rails_root: 'fake_root')
+    end
+  end
+
+  describe '#configure_formatter' do
+    subject { described_class.configure_formatter(rspec_config:, rails_root:) }
+
+    let(:rspec_config) { instance_double(RSpec::Core::Configuration, pattern:, files_to_run:) }
+    let(:rails_root) { "#{fixture_directory}/fake_rails_root" }
+    let(:files_to_run) { ["#{rails_root}/spec/lib/lib_spec.rb", "#{rails_root}/spec/models/model_spec.rb"] }
+    let(:pattern) { '**{,/*/**}/*_spec.rb' }
+    let(:inclusion_rules) { instance_double(RSpec::Core::InclusionRules, rules: {}) } # no rules means run all
+
+    before { allow(rspec_config).to receive(:inclusion_filter).and_return(inclusion_rules) }
+
+    context 'running all specs' do
+      let(:pattern) { '**{,/*/**}/*_spec.rb' }
+
+      it 'does not filter files' do
+        expect { subject }.not_to change { SimpleCov::Inline::Formatter.config.files }.from(nil)
+      end
+
+      it 'does not supress output' do
+        expect { subject }.not_to change { SimpleCov::Inline::Formatter.config.no_output }.from(nil)
+      end
+    end
+
+    context 'running only a lib spec' do
+      let(:files_to_run) { ["#{rails_root}/spec/lib/lib_spec.rb"] }
+
+      it 'does not supress output' do
+        expect { subject }.not_to change { SimpleCov::Inline::Formatter.config.no_output }.from(nil)
+      end
+
+      it 'filters by the spec file and the file it is testing' do
+        expect { subject }
+          .to change { SimpleCov::Inline::Formatter.config.files }
+          .from(nil).to(["#{rails_root}/spec/lib/lib_spec.rb", "#{rails_root}/lib/lib.rb"])
+      end
+    end
+
+    context 'running only a model spec' do
+      let(:files_to_run) { ["#{rails_root}/spec/models/model_spec.rb"] }
+
+      it 'does not supress output' do
+        expect { subject }.not_to change { SimpleCov::Inline::Formatter.config.no_output }.from(nil)
+      end
+
+      it 'filters by the spec file and the file it is testing' do
+        expect { subject }
+          .to change { SimpleCov::Inline::Formatter.config.files }
+          .from(nil).to(["#{rails_root}/spec/models/model_spec.rb", "#{rails_root}/app/models/model.rb"])
+      end
+    end
+
+    context 'filtered to a line of code' do
+      let(:files_to_run) { ["#{rails_root}/spec/models/model_spec.rb"] }
+      let(:inclusion_rules) do
+        instance_double(
+          RSpec::Core::InclusionRules,
+          rules: {focus: true, locations: {"#{rails_root}/spec/models/model_spec.rb" => [5]}}, # 5 is the line number
+        )
+      end
+
+      it 'supresses output' do
+        expect { subject }
+          .to change { SimpleCov::Inline::Formatter.config.no_output }
+          .from(nil)
+          .to('filtered to line of code')
+      end
+
+      it 'does not filter files' do
+        expect { subject }.not_to change { SimpleCov::Inline::Formatter.config.files }.from(nil)
+      end
+    end
+
+    context 'bad spec path' do
+      let(:files_to_run) { ['/not/rails/root/spec/models/model_spec.rb'] }
+
+      it 'filters by the spec file and the file it is testing' do
+        expect { subject }.to raise_error RuntimeError, 'Spec file must be in rails root.'
+      end
+    end
+
+    context 'directory provided' do
+      let(:files_to_run) { ["#{rails_root}/spec/models"] }
+
+      it 'does not supress output' do
+        expect { subject }.not_to change { SimpleCov::Inline::Formatter.config.no_output }.from(nil)
+      end
+
+      it 'only filters to the spec directory and does inlcude the covered files' do
+        # Existing behaviour. Feels like it should suppress instead.
+        expect { subject }
+          .to change { SimpleCov::Inline::Formatter.config.files }
+          .from(nil).to(["#{rails_root}/spec/models"])
+      end
+    end
+  end
+end

spec/lib/simplecov/inline/rspec_formatter_skip_on_failure_spec.rb

@@ -0,0 +1,44 @@
+RSpec.describe SimpleCov::Inline::RSpecFormatterSkipOnFailure do
+  after { SimpleCov::Inline::Formatter.reset_config }
+
+  describe '#dump_failures' do
+    subject { described_class.new(:output_arg_value_not_used).dump_failures(notification) }
+
+    let(:notification) do
+      instance_double(RSpec::Core::Notifications::ExamplesNotification, examples:, failed_examples:)
+    end
+
+    context 'no specs ran' do
+      let(:examples) { [] }
+      let(:failed_examples) { [] }
+
+      it 'supresses output' do
+        expect { subject }
+          .to change { SimpleCov::Inline::Formatter.config.no_output }
+          .from(nil)
+          .to('no examples were run')
+      end
+    end
+
+    context 'specs ran but there were failures' do
+      let(:examples) { ['a_spec.rb', 'b_spec.rb'] }
+      let(:failed_examples) { ['a_spec.rb'] }
+
+      it 'supresses output' do
+        expect { subject }
+          .to change { SimpleCov::Inline::Formatter.config.no_output }
+          .from(nil)
+          .to('some specs failed')
+      end
+    end
+
+    context 'some specs ran without error' do
+      let(:examples) { ['a_spec.rb', 'b_spec.rb'] }
+      let(:failed_examples) { [] }
+
+      it 'does not supress output' do
+        expect { subject }.not_to change { SimpleCov::Inline::Formatter.config.no_output }.from(nil)
+      end
+    end
+  end
+end