Improve specs styles/organization and add some more specs

spec/lib/ci/gitlab_ci_yaml_processor_spec.rb

@@ -20,7 +20,7 @@ module Ci
             it { is_expected.to include(coverage_regex: '\(\d+\.\d+\) covered') }
           end
-          context 'but \'rspec\' job also has coverage set' do
+          context "but 'rspec' job also has coverage set" do
             before do
               config_base[:rspec][:coverage] = '/Code coverage: \d+\.\d+/'
             end

spec/lib/gitlab/ci/config/entry/coverage_spec.rb

@@ -4,12 +4,31 @@ describe Gitlab::Ci::Config::Entry::Coverage do
   let(:entry) { described_class.new(config) }
   describe 'validations' do
-    context 'when entry config value is correct' do
+    context "when entry config value is correct without surrounding '/'" do
       let(:config) { 'Code coverage: \d+\.\d+' }
       describe '#value' do
         subject { entry.value }
-        it { is_expected.to eq config }
+        it { is_expected.to eq(config) }
+      end
+
+      describe '#errors' do
+        subject { entry.errors }
+        it { is_expected.to be_empty }
+      end
+
+      describe '#valid?' do
+        subject { entry }
+        it { is_expected.to be_valid }
+      end
+    end
+
+    context "when entry config value is correct with surrounding '/'" do
+      let(:config) { '/Code coverage: \d+\.\d+/' }
+
+      describe '#value' do
+        subject { entry.value }
+        it { is_expected.to eq(config[1...-1]) }
       end
       describe '#errors' do
@@ -28,7 +47,7 @@ describe Gitlab::Ci::Config::Entry::Coverage do
       describe '#errors' do
         subject { entry.errors }
-        it { is_expected.to include /coverage config must be a regular expression/ }
+        it { is_expected.to include(/coverage config must be a regular expression/) }
       end
       describe '#valid?' do

spec/lib/gitlab/ci/config/entry/global_spec.rb

@@ -4,19 +4,17 @@ describe Gitlab::Ci::Config::Entry::Global do
   let(:global) { described_class.new(hash) }
   describe '.nodes' do
-    subject { described_class.nodes }
-
-    it { is_expected.to be_a Hash }
+    it 'returns a hash' do
+      expect(described_class.nodes).to be_a(Hash)
+    end
     context 'when filtering all the entry/node names' do
-      subject { described_class.nodes.keys }
-
-      let(:result) do
-        %i[before_script image services after_script variables stages types
-           cache coverage]
+      it 'contains the expected node names' do
+        node_names = described_class.nodes.keys
+        expect(node_names).to match_array(%i[before_script image services
+                                             after_script variables stages
+                                             types cache coverage])
       end
-
-      it { is_expected.to match_array result }
     end
   end

spec/models/ci/build_spec.rb

@@ -251,12 +251,13 @@ describe Ci::Build, :models do
   end
   describe '#update_coverage' do
-    it 'grants coverage_regex method is called inside of it' do
-      build.coverage_regex = '\(\d+.\d+\%\) covered'
-      allow(build).to receive(:trace) { 'Coverage 1033 / 1051 LOC (98.29%) covered' }
-      allow(build).to receive(:coverage_regex).and_call_original
-      expect(build).to receive(:update_attributes).with(coverage: 98.29) { true }
-      expect(build.update_coverage).to be true
+    context "regarding coverage_regex's value," do
+      it "saves the correct extracted coverage value" do
+        build.coverage_regex = '\(\d+.\d+\%\) covered'
+        allow(build).to receive(:trace) { 'Coverage 1033 / 1051 LOC (98.29%) covered' }
+        expect(build).to receive(:update_attributes).with(coverage: 98.29) { true }
+        expect(build.update_coverage).to be true
+      end
     end
   end