Merge pull request #294 from rodjek/sdk-369

(PDK-369) Improve error context for pdk test unit failures

lib/pdk/report/event.rb

@@ -96,7 +96,20 @@ def to_text
         location = nil if location.empty?
 
         # TODO: maybe add trace
-        [severity, source, location, message].compact.join(': ')
+        header = [severity, source, location, message].compact.join(': ')
+        if source == 'rspec'
+          result = [header, "  #{test}"]
+          context = context_lines
+          unless context.nil?
+            result << '  Failure/Error:'
+            result.concat(context)
+            result << "\n"
+          end
+
+          result.compact.join("\n")
+        else
+          header
+        end
       end
 
       # Renders the event as a JUnit XML testcase.
@@ -302,6 +315,24 @@ def sanitise_trace(value)
           (line =~ %r{/gems/}) || (line =~ %r{bin/rspec:})
         end
       end
+
+      # Extract contextual information for the event from the file that it
+      # references.
+      #
+      # @param max_num_lines [Integer] The maximum number of lines to return.
+      #
+      # @return [Array] Array of lines from the file, centred on the line
+      #   number of the event.
+      def context_lines(max_num_lines = 5)
+        return if file.nil? || line.nil?
+
+        file_content = File.read(file).split("\n")
+        delta = (max_num_lines - 1) / 2
+        min = [0, (line - 1) - delta].max
+        max = [(line - 1) + delta, file_content.length].min
+
+        file_content[min..max].map { |r| "  #{r}" }
+      end
     end
   end
 end

spec/unit/pdk/report/event_spec.rb

@@ -386,6 +386,50 @@
           expect(text_event).to match(%r{testfile\.rb:123:456})
         end
       end
+
+      context 'it includes a snippet of the file for rspec events' do
+        let(:data) do
+          {
+            line:    4,
+            source:  'rspec',
+            message: 'test message',
+            severity: 'failure',
+            test:     'spec description',
+            state:    :failure,
+          }
+        end
+
+        let(:file_content) do
+          [
+            'line 1',
+            'line 2',
+            'line 3',
+            'line 4',
+            'line 5',
+          ].join("\n")
+        end
+
+        let(:expected_text) do
+          <<-END.gsub(%r{^ {12}}, '')
+            failure: rspec: testfile.rb:4: test message
+              spec description
+              Failure/Error:
+              line 2
+              line 3
+              line 4
+              line 5
+
+          END
+        end
+
+        before(:each) do
+          allow(File).to receive(:read).with('testfile.rb').and_return(file_content)
+        end
+
+        it 'renders the event with context' do
+          expect(text_event).to eq(expected_text)
+        end
+      end
     end
 
     context 'and a severity is provided' do