feat: report uncovered lines

pkg/testcoverage/check.go

@@ -86,9 +86,10 @@ func Analyze(cfg Config, current, base []coverage.Stats) AnalyzeResult {
 		PackagesBelowThreshold: checkCoverageStatsBelowThreshold(
 			makePackageStats(current), thr.Package, overrideRules,
 		),
-		TotalStats:       coverage.CalcTotalStats(current),
-		HasBaseBreakdown: len(base) > 0,
-		Diff:             calculateStatsDiff(current, base),
+		FilesWithUncoveredLines: coverage.StatsFilterWithUncoveredLines(current),
+		TotalStats:              coverage.CalcTotalStats(current),
+		HasBaseBreakdown:        len(base) > 0,
+		Diff:                    calculateStatsDiff(current, base),
 	}
 }
 

pkg/testcoverage/check_test.go

@@ -30,7 +30,7 @@ func TestCheck(t *testing.T) {
 		return
 	}
 
-	prefix := "github.com/vladopajic/go-test-coverage/v2"
+	const prefix = "github.com/vladopajic/go-test-coverage/v2"
 
 	t.Run("no profile", func(t *testing.T) {
 		t.Parallel()
@@ -40,6 +40,7 @@ func TestCheck(t *testing.T) {
 		assert.False(t, pass)
 		assertGithubActionErrorsCount(t, buf.String(), 0)
 		assertHumanReport(t, buf.String(), 0, 0)
+		assertNoUncoveredLinesInfo(t, buf.String())
 	})
 
 	t.Run("invalid profile", func(t *testing.T) {
@@ -51,6 +52,7 @@ func TestCheck(t *testing.T) {
 		assert.False(t, pass)
 		assertGithubActionErrorsCount(t, buf.String(), 0)
 		assertHumanReport(t, buf.String(), 0, 0)
+		assertNoUncoveredLinesInfo(t, buf.String())
 	})
 
 	t.Run("valid profile - pass", func(t *testing.T) {
@@ -62,6 +64,7 @@ func TestCheck(t *testing.T) {
 		assert.True(t, pass)
 		assertGithubActionErrorsCount(t, buf.String(), 0)
 		assertHumanReport(t, buf.String(), 1, 0)
+		assertNoUncoveredLinesInfo(t, buf.String())
 	})
 
 	t.Run("valid profile with exclude - pass", func(t *testing.T) {
@@ -79,6 +82,7 @@ func TestCheck(t *testing.T) {
 		assert.True(t, pass)
 		assertGithubActionErrorsCount(t, buf.String(), 0)
 		assertHumanReport(t, buf.String(), 1, 0)
+		assertNoUncoveredLinesInfo(t, buf.String())
 	})
 
 	t.Run("valid profile - fail", func(t *testing.T) {
@@ -90,10 +94,15 @@ func TestCheck(t *testing.T) {
 		assert.False(t, pass)
 		assertGithubActionErrorsCount(t, buf.String(), 0)
 		assertHumanReport(t, buf.String(), 0, 1)
-		assert.GreaterOrEqual(t, strings.Count(buf.String(), prefix), 0)
+		assertHasUncoveredLinesInfo(t, buf.String(), []string{
+			"pkg/testcoverage/badgestorer/cdn.go",
+			"pkg/testcoverage/badgestorer/github.go",
+			"pkg/testcoverage/check.go",
+			"pkg/testcoverage/coverage/cover.go",
+		})
 	})
 
-	t.Run("valid profile - fail with prefix", func(t *testing.T) {
+	t.Run("valid profile - pass with prefix", func(t *testing.T) {
 		t.Parallel()
 
 		buf := &bytes.Buffer{}
@@ -103,7 +112,8 @@ func TestCheck(t *testing.T) {
 		assert.True(t, pass)
 		assertGithubActionErrorsCount(t, buf.String(), 0)
 		assertHumanReport(t, buf.String(), 1, 0)
-		assert.Equal(t, 0, strings.Count(buf.String(), prefix))
+		assertNoFileNames(t, buf.String(), prefix)
+		assertNoUncoveredLinesInfo(t, buf.String())
 	})
 
 	t.Run("valid profile - pass after override", func(t *testing.T) {
@@ -119,7 +129,8 @@ func TestCheck(t *testing.T) {
 		assert.True(t, pass)
 		assertGithubActionErrorsCount(t, buf.String(), 0)
 		assertHumanReport(t, buf.String(), 2, 0)
-		assert.GreaterOrEqual(t, strings.Count(buf.String(), prefix), 0)
+		assertNoFileNames(t, buf.String(), prefix)
+		assertNoUncoveredLinesInfo(t, buf.String())
 	})
 
 	t.Run("valid profile - fail after override", func(t *testing.T) {
@@ -135,7 +146,12 @@ func TestCheck(t *testing.T) {
 		assert.False(t, pass)
 		assertGithubActionErrorsCount(t, buf.String(), 0)
 		assertHumanReport(t, buf.String(), 0, 2)
-		assert.GreaterOrEqual(t, strings.Count(buf.String(), prefix), 0)
+		assertHasUncoveredLinesInfo(t, buf.String(), []string{
+			"pkg/testcoverage/badgestorer/cdn.go",
+			"pkg/testcoverage/badgestorer/github.go",
+			"pkg/testcoverage/check.go",
+			"pkg/testcoverage/coverage/cover.go",
+		})
 	})
 
 	t.Run("valid profile - pass after file override", func(t *testing.T) {
@@ -151,7 +167,8 @@ func TestCheck(t *testing.T) {
 		assert.True(t, pass)
 		assertGithubActionErrorsCount(t, buf.String(), 0)
 		assertHumanReport(t, buf.String(), 1, 0)
-		assert.GreaterOrEqual(t, strings.Count(buf.String(), prefix), 0)
+		assertNoFileNames(t, buf.String(), prefix)
+		assertNoUncoveredLinesInfo(t, buf.String())
 	})
 
 	t.Run("valid profile - fail after file override", func(t *testing.T) {
@@ -168,6 +185,12 @@ func TestCheck(t *testing.T) {
 		assertGithubActionErrorsCount(t, buf.String(), 0)
 		assertHumanReport(t, buf.String(), 0, 1)
 		assert.GreaterOrEqual(t, strings.Count(buf.String(), prefix), 0)
+		assertHasUncoveredLinesInfo(t, buf.String(), []string{
+			"pkg/testcoverage/badgestorer/cdn.go",
+			"pkg/testcoverage/badgestorer/github.go",
+			"pkg/testcoverage/check.go",
+			"pkg/testcoverage/coverage/cover.go",
+		})
 	})
 
 	t.Run("valid profile - fail couldn't save badge", func(t *testing.T) {
@@ -260,6 +283,7 @@ func TestCheckNoParallel(t *testing.T) {
 		assertGithubActionErrorsCount(t, buf.String(), 0)
 		assertHumanReport(t, buf.String(), 1, 0)
 		assertGithubOutputValues(t, testFile)
+		assertNoUncoveredLinesInfo(t, buf.String())
 	})
 
 	t.Run("ok fail; with github output file", func(t *testing.T) {
@@ -273,6 +297,7 @@ func TestCheckNoParallel(t *testing.T) {
 		assertGithubActionErrorsCount(t, buf.String(), 1)
 		assertHumanReport(t, buf.String(), 0, 1)
 		assertGithubOutputValues(t, testFile)
+		assertHasUncoveredLinesInfo(t, buf.String(), []string{})
 	})
 }
 

pkg/testcoverage/coverage/cover.go

@@ -8,6 +8,7 @@ import (
 	"go/token"
 	"os"
 	"path/filepath"
+	"sort"
 	"strings"
 
 	"golang.org/x/tools/cover"
@@ -258,27 +259,35 @@ func sumCoverage(profile *cover.Profile, funcs, blocks, annotations []extent) St
 	s := Stats{}
 
 	for _, f := range funcs {
-		c, t := coverage(profile, f, blocks, annotations)
+		c, t, ul := coverage(profile, f, blocks, annotations)
 		s.Total += t
 		s.Covered += c
+		s.UncoveredLines = append(s.UncoveredLines, ul...)
 	}
 
+	s.UncoveredLines = dedup(s.UncoveredLines)
+
 	return s
 }
 
 // coverage returns the fraction of the statements in the
 // function that were covered, as a numerator and denominator.
 //
-//nolint:cyclop,gocognit // relax
-func coverage(profile *cover.Profile, f extent, blocks, annotations []extent) (int64, int64) {
+//nolint:cyclop,gocognit,maintidx // relax
+func coverage(
+	profile *cover.Profile,
+	f extent,
+	blocks, annotations []extent,
+) (int64, int64, []int) {
 	if hasExtentWithStartLine(annotations, f.StartLine) {
 		// case when entire function is ignored
-		return 0, 0
+		return 0, 0, nil
 	}
 
 	var (
 		covered, total int64
 		skip           extent
+		uncoveredLines []int
 	)
 
 	// the blocks are sorted, so we can stop counting as soon as
@@ -312,8 +321,29 @@ func coverage(profile *cover.Profile, f extent, blocks, annotations []extent) (i
 
 		if b.Count > 0 {
 			covered += int64(b.NumStmt)
+		} else {
+			for i := range (b.EndLine - b.StartLine) + 1 {
+				uncoveredLines = append(uncoveredLines, b.StartLine+i)
+			}
+		}
+	}
+
+	return covered, total, uncoveredLines
+}
+
+func dedup(ss []int) []int {
+	if len(ss) <= 1 {
+		return ss
+	}
+
+	sort.Ints(ss)
+	result := []int{ss[0]}
+
+	for i := 1; i < len(ss); i++ {
+		if ss[i] != ss[i-1] {
+			result = append(result, ss[i])
 		}
 	}
 
-	return covered, total
+	return result
 }

pkg/testcoverage/coverage/cover_test.go

@@ -206,7 +206,10 @@ func Test_sumCoverage(t *testing.T) {
 	}}
 
 	s := SumCoverage(profile, funcs, nil, nil)
-	assert.Equal(t, Stats{Total: 10, Covered: 0}, s)
+	expected := Stats{Total: 10, Covered: 0, UncoveredLines: []int{
+		1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20,
+	}}
+	assert.Equal(t, expected, s)
 
 	// Coverage should be empty when every function is excluded
 	s = SumCoverage(profile, funcs, nil, funcs)
@@ -216,7 +219,10 @@ func Test_sumCoverage(t *testing.T) {
 	annotations := []Extent{{StartLine: 4, EndLine: 4}}
 	blocks := []Extent{{StartLine: 4, EndLine: 10}}
 	s = SumCoverage(profile, funcs, blocks, annotations)
-	assert.Equal(t, Stats{Total: 7, Covered: 0}, s)
+	expected = Stats{Total: 7, Covered: 0, UncoveredLines: []int{
+		1, 2, 3, 12, 13, 14, 15, 16, 17, 18, 19, 20,
+	}}
+	assert.Equal(t, expected, s)
 }
 
 func pluckStartLine(extents []Extent) []int {

pkg/testcoverage/coverage/types.go

@@ -11,13 +11,14 @@ import (
 )
 
 type Stats struct {
-	Name      string
-	Total     int64
-	Covered   int64
-	Threshold int
+	Name           string
+	Total          int64
+	Covered        int64
+	Threshold      int
+	UncoveredLines []int
 }
 
-func (s Stats) UncoveredLines() int {
+func (s Stats) UncoveredLinesCount() int {
 	return int(s.Total - s.Covered)
 }
 
@@ -118,6 +119,40 @@ func CalcTotalStats(stats []Stats) Stats {
 	return total
 }
 
+func StatsPluckName(stats []Stats) []string {
+	result := make([]string, len(stats))
+
+	for i, s := range stats {
+		result[i] = s.Name
+	}
+
+	return result
+}
+
+func StatsFilterWithUncoveredLines(stats []Stats) []Stats {
+	return filter(stats, func(s Stats) bool {
+		return len(s.UncoveredLines) > 0
+	})
+}
+
+func StatsFilterWithCoveredLines(stats []Stats) []Stats {
+	return filter(stats, func(s Stats) bool {
+		return len(s.UncoveredLines) == 0
+	})
+}
+
+func filter[T any](slice []T, predicate func(T) bool) []T {
+	var result []T
+
+	for _, value := range slice {
+		if predicate(value) {
+			result = append(result, value)
+		}
+	}
+
+	return result
+}
+
 func SerializeStats(stats []Stats) []byte {
 	b := bytes.Buffer{}
 	sep, nl := []byte(";"), []byte("\n")

pkg/testcoverage/export_test.go

@@ -15,6 +15,8 @@ var (
 	GenerateAndSaveBadge      = generateAndSaveBadge
 	SetOutputValue            = setOutputValue
 	LoadBaseCoverageBreakdown = loadBaseCoverageBreakdown
+	CompressUncoveredLines    = compressUncoveredLines
+	ReportUncoveredLines      = reportUncoveredLines
 )
 
 type (