dashboard/app: filter coverage by minspread

Coverage spread is the max_coverage-min_coverage for the time period.
Minspread 0 means show all records.
Minspread 10 means show only the records where coverage was floating +/- 5%.

Author: tarasmadan

dashboard/app/coverage.go

@@ -50,7 +50,7 @@ func GetCoverageDBClient(ctx context.Context) spannerclient.SpannerClient {
 
 type funcStyleBodyJS func(
 	ctx context.Context, client spannerclient.SpannerClient,
-	scope *coveragedb.SelectScope, onlyUnique bool, sss, managers []string,
+	scope *coveragedb.SelectScope, onlyUnique bool, sss, managers []string, dataFilters cover.Format,
 ) (template.CSS, template.HTML, template.HTML, error)
 
 func handleCoverageHeatmap(c context.Context, w http.ResponseWriter, r *http.Request) error {
@@ -121,6 +121,11 @@ func handleHeatmap(c context.Context, w http.ResponseWriter, r *http.Request, f
 
 	onlyUnique := r.FormValue("unique-only") == "1"
 
+	minSpread, err := strconv.Atoi("0" + r.FormValue("minspread"))
+	if err != nil {
+		return fmt.Errorf("minspread should be integer")
+	}
+
 	var style template.CSS
 	var body, js template.HTML
 	if style, body, js, err = f(c, GetCoverageDBClient(c),
@@ -130,7 +135,11 @@ func handleHeatmap(c context.Context, w http.ResponseWriter, r *http.Request, f
 			Manager:   manager,
 			Periods:   periods,
 		},
-		onlyUnique, subsystems, managers); err != nil {
+		onlyUnique, subsystems, managers,
+		cover.Format{
+			FilterMinSpread:         minSpread,
+			OrderByInstrumentedDrop: minSpread != 0,
+		}); err != nil {
 		return fmt.Errorf("failed to generate heatmap: %w", err)
 	}
 	return serveTemplate(w, "custom_content.html", struct {

pkg/cover/heatmap.go

@@ -9,6 +9,7 @@ import (
 	_ "embed"
 	"fmt"
 	"html/template"
+	"slices"
 	"sort"
 	"strings"
 
@@ -21,7 +22,8 @@ import (
 type templateHeatmapRow struct {
 	Items               []*templateHeatmapRow
 	Name                string
-	Coverage            []int64
+	Coverage            []int64 // in percents
+	Covered             []int64 // in lines count
 	IsDir               bool
 	Depth               int
 	LastDayInstrumented int64
@@ -41,6 +43,33 @@ type templateHeatmap struct {
 	Managers   []string
 }
 
+// Filter removes the records where predicate is true.
+func (th *templateHeatmap) Filter(pred func(*templateHeatmapRow) bool) {
+	th.Root.filter(pred)
+}
+
+func (th *templateHeatmap) Sort(pred func(*templateHeatmapRow, *templateHeatmapRow) int) {
+	th.Root.sort(pred)
+}
+
+func (thm *templateHeatmapRow) filter(pred func(*templateHeatmapRow) bool) {
+	var filteredItems []*templateHeatmapRow
+	for _, item := range thm.Items {
+		item.filter(pred)
+		if pred(item) {
+			filteredItems = append(filteredItems, item)
+		}
+	}
+	thm.Items = filteredItems
+}
+
+func (thm *templateHeatmapRow) sort(pred func(*templateHeatmapRow, *templateHeatmapRow) int) {
+	for _, item := range thm.Items {
+		item.sort(pred)
+	}
+	slices.SortFunc(thm.Items, pred)
+}
+
 func (thm *templateHeatmapRow) addParts(depth int, pathLeft []string, filePath string, instrumented, covered int64,
 	timePeriod coveragedb.TimePeriod) {
 	thm.instrumented[timePeriod] += instrumented
@@ -94,6 +123,7 @@ func (thm *templateHeatmapRow) prepareDataFor(pageColumns []pageColumnTarget, sk
 			dateCoverage = percent(thm.covered[tp], thm.instrumented[tp])
 		}
 		thm.Coverage = append(thm.Coverage, dateCoverage)
+		thm.Covered = append(thm.Covered, thm.covered[tp])
 		thm.Tooltips = append(thm.Tooltips, fmt.Sprintf("Instrumented:\t%d blocks\nCovered:\t%d blocks",
 			thm.instrumented[tp], thm.covered[tp]))
 		if !thm.IsDir {
@@ -179,22 +209,30 @@ func stylesBodyJSTemplate(templData *templateHeatmap,
 		template.HTML(js.Bytes()), nil
 }
 
+type Format struct {
+	FilterMinSpread         int
+	OrderByInstrumentedDrop bool
+	// TODO(tarasmadan): move onlyUnique here as a filter
+}
+
 func DoHeatMapStyleBodyJS(
 	ctx context.Context, client spannerclient.SpannerClient, scope *coveragedb.SelectScope, onlyUnique bool,
-	sss, managers []string) (template.CSS, template.HTML, template.HTML, error) {
+	sss, managers []string, dataFilters Format) (template.CSS, template.HTML, template.HTML, error) {
 	covAndDates, err := coveragedb.FilesCoverageWithDetails(ctx, client, scope, onlyUnique)
 	if err != nil {
 		return "", "", "", fmt.Errorf("failed to FilesCoverageWithDetails: %w", err)
 	}
 	templData := filesCoverageToTemplateData(covAndDates, onlyUnique)
 	templData.Subsystems = sss
 	templData.Managers = managers
+	FormatResult(templData, dataFilters)
+
 	return stylesBodyJSTemplate(templData)
 }
 
 func DoSubsystemsHeatMapStyleBodyJS(
 	ctx context.Context, client spannerclient.SpannerClient, scope *coveragedb.SelectScope, onlyUnique bool,
-	sss, managers []string) (template.CSS, template.HTML, template.HTML, error) {
+	sss, managers []string, format Format) (template.CSS, template.HTML, template.HTML, error) {
 	covWithDetails, err := coveragedb.FilesCoverageWithDetails(ctx, client, scope, onlyUnique)
 	if err != nil {
 		panic(err)
@@ -215,9 +253,28 @@ func DoSubsystemsHeatMapStyleBodyJS(
 	}
 	templData := filesCoverageToTemplateData(ssCovAndDates, onlyUnique)
 	templData.Managers = managers
+	FormatResult(templData, format)
 	return stylesBodyJSTemplate(templData)
 }
 
+func FormatResult(thm *templateHeatmap, format Format) {
+	if format.FilterMinSpread > 0 {
+		thm.Filter(func(row *templateHeatmapRow) bool {
+			if row.IsDir && len(row.Items) > 0 {
+				return true
+			}
+			return row.Coverage[len(row.Coverage)-1]-slices.Min(row.Coverage) >= int64(format.FilterMinSpread)
+		})
+	}
+	if format.OrderByInstrumentedDrop {
+		thm.Sort(func(row1 *templateHeatmapRow, row2 *templateHeatmapRow) int {
+			row1InstrDrop := slices.Max(row1.Covered) - row1.Covered[len(row1.Covered)-1]
+			row2InstrDrop := slices.Max(row2.Covered) - row2.Covered[len(row2.Covered)-1]
+			return int(row2InstrDrop - row1InstrDrop)
+		})
+	}
+}
+
 func approximateInstrumented(points int64) string {
 	dim := "_"
 	if points > 10000 {

pkg/cover/heatmap_test.go

@@ -45,6 +45,7 @@ func TestFilesCoverageToTemplateData(t *testing.T) {
 						{
 							Name:                "file1",
 							Coverage:            []int64{100},
+							Covered:             []int64{1},
 							IsDir:               false,
 							Depth:               0,
 							LastDayInstrumented: 1,
@@ -57,6 +58,7 @@ func TestFilesCoverageToTemplateData(t *testing.T) {
 					},
 					Name:                "",
 					Coverage:            []int64{100},
+					Covered:             []int64{1},
 					IsDir:               true,
 					Depth:               0,
 					LastDayInstrumented: 1,
@@ -93,6 +95,7 @@ func TestFilesCoverageToTemplateData(t *testing.T) {
 								{
 									Name:                "file1",
 									Coverage:            []int64{100, 0},
+									Covered:             []int64{1, 0},
 									IsDir:               false,
 									Depth:               1,
 									LastDayInstrumented: 0,
@@ -107,6 +110,7 @@ func TestFilesCoverageToTemplateData(t *testing.T) {
 								{
 									Name:                "file2",
 									Coverage:            []int64{0, 0},
+									Covered:             []int64{0, 0},
 									IsDir:               false,
 									Depth:               1,
 									LastDayInstrumented: 1,
@@ -121,6 +125,7 @@ func TestFilesCoverageToTemplateData(t *testing.T) {
 							},
 							Name:                "dir",
 							Coverage:            []int64{100, 0},
+							Covered:             []int64{1, 0},
 							IsDir:               true,
 							Depth:               0,
 							LastDayInstrumented: 1,
@@ -132,6 +137,7 @@ func TestFilesCoverageToTemplateData(t *testing.T) {
 					},
 					Name:                "",
 					Coverage:            []int64{100, 0},
+					Covered:             []int64{1, 0},
 					LastDayInstrumented: 1,
 					Tooltips: []string{
 						"Instrumented:\t1 blocks\nCovered:\t1 blocks",
@@ -157,6 +163,7 @@ func TestFilesCoverageToTemplateData(t *testing.T) {
 			want: &templateHeatmap{
 				Root: &templateHeatmapRow{
 					Coverage:            []int64{0},
+					Covered:             []int64{0},
 					IsDir:               true,
 					LastDayInstrumented: 1,
 					Tooltips:            []string{"Instrumented:\t1 blocks\nCovered:\t0 blocks"},