refactor(ui): bring back SummaryData, minor cleanup

As per [1], it would be preferable to keep this struct. Though I renamed
some fields and removed the dependency on the entire lib.Options, since
it only requires one value.

This also renames Summary.Write to Summary.SummarizeMetrics, as it's a
more accurate description of what happens, despite of the
"Summary.Summarize" stutter.

[1]: #1143 (comment)

cmd/run.go

@@ -451,8 +451,13 @@ a commandline interface for interacting with it.`,
 			}
 
 			fprintf(stdout, "\n")
-			s.Write(stdout, "", engine.Executor.GetRunner().GetDefaultGroup(),
-				engine.Executor.GetTime(), conf.SummaryTimeUnit.String, engine.Metrics)
+			s.SummarizeMetrics(stdout, "", ui.SummaryData{
+				Metrics:   engine.Metrics,
+				RootGroup: engine.Executor.GetRunner().GetDefaultGroup(),
+				Time:      engine.Executor.GetTime(),
+				TimeUnit:  conf.Options.SummaryTimeUnit.String,
+			})
+
 			fprintf(stdout, "\n")
 		}
 

ui/summary.go

@@ -370,11 +370,18 @@ func (s *Summary) summarizeMetrics(w io.Writer, indent string, t time.Duration,
 	}
 }
 
-// Write writes the metrics summary to w
-func (s *Summary) Write(w io.Writer, indent string, group *lib.Group,
-	t time.Duration, timeUnit string, metrics map[string]*stats.Metric) {
-	if group != nil {
-		summarizeGroup(w, indent+"    ", group)
+// SummaryData represents data passed to Summary.SummarizeMetrics
+type SummaryData struct {
+	Metrics   map[string]*stats.Metric
+	RootGroup *lib.Group
+	Time      time.Duration
+	TimeUnit  string
+}
+
+// SummarizeMetrics creates a summary of provided metrics and writes it to w.
+func (s *Summary) SummarizeMetrics(w io.Writer, indent string, data SummaryData) {
+	if data.RootGroup != nil {
+		summarizeGroup(w, indent+"    ", data.RootGroup)
 	}
-	s.summarizeMetrics(w, indent+"  ", t, timeUnit, metrics)
+	s.summarizeMetrics(w, indent+"  ", data.Time, data.TimeUnit, data.Metrics)
 }

ui/summary_test.go

@@ -57,7 +57,7 @@ func TestSummary(t *testing.T) {
 		}
 	})
 
-	t.Run("Write", func(t *testing.T) {
+	t.Run("SummarizeMetrics", func(t *testing.T) {
 		var (
 			checksOut = "   ✓ checks......: 100.00% ✓ 3   ✗ 0  \n"
 			countOut  = "   ✗ http_reqs...: 3       3/s\n"
@@ -80,7 +80,13 @@ func TestSummary(t *testing.T) {
 			t.Run(fmt.Sprintf("%v", tc.stats), func(t *testing.T) {
 				var w bytes.Buffer
 				s, _ := NewSummary(tc.stats)
-				s.Write(&w, " ", nil, time.Second, "", metrics)
+
+				s.SummarizeMetrics(&w, " ", SummaryData{
+					Metrics:   metrics,
+					RootGroup: nil,
+					Time:      time.Second,
+					TimeUnit:  "",
+				})
 				assert.Equal(t, tc.expected, w.String())
 			})
 		}