parser/gotest: add SubtestMode to configure how to deal with subtests

parser/gotest/gotest.go

@@ -57,6 +57,50 @@ func TimestampFunc(f func() time.Time) Option {
 	}
 }
 
+// SubtestMode configures how Go subtests should be handled by the parser.
+type SubtestMode string
+
+const (
+	// SubtestModeDefault is the default subtest mode. It treats tests with
+	// subtests as any other tests.
+	SubtestModeDefault SubtestMode = ""
+
+	// IgnoreParentResults ignores test results for tests with subtests. Use
+	// this mode if you use subtest parents for common setup/teardown, but are
+	// not interested in counting them as failed tests. Ignoring their results
+	// still preserves these tests and their captured output in the report.
+	IgnoreParentResults SubtestMode = "ignore-parent-results"
+
+	// ExcludeParents excludes tests that contain subtests from the report.
+	// Note that the subtests themselves are not removed. Use this mode if you
+	// use subtest parents for common setup/teardown, but are not actually
+	// interested in their presence in the created report. If output was
+	// captured for tests that are removed, the output is preserved in the
+	// global report output.
+	ExcludeParents SubtestMode = "exclude-parents"
+)
+
+// ParseSubtestMode returns a SubtestMode for the given string.
+func ParseSubtestMode(in string) (SubtestMode, error) {
+	switch in {
+	case string(IgnoreParentResults):
+		return IgnoreParentResults, nil
+	case string(ExcludeParents):
+		return ExcludeParents, nil
+	default:
+		return SubtestModeDefault, fmt.Errorf("unknown subtest mode: %v", in)
+	}
+}
+
+// SetSubtestMode is an Option to change how the parser handles tests with
+// subtests. See the documentation for the individual SubtestModes for more
+// information.
+func SetSubtestMode(mode SubtestMode) Option {
+	return func(p *Parser) {
+		p.subtestMode = mode
+	}
+}
+
 // NewParser returns a new Go test output parser.
 func NewParser(options ...Option) *Parser {
 	p := &Parser{}
@@ -68,7 +112,9 @@ func NewParser(options ...Option) *Parser {
 
 // Parser is a Go test output Parser.
 type Parser struct {
-	packageName   string
+	packageName string
+	subtestMode SubtestMode
+
 	timestampFunc func() time.Time
 
 	events []Event
@@ -89,6 +135,7 @@ func (p *Parser) Parse(r io.Reader) (gtr.Report, error) {
 func (p *Parser) report(events []Event) gtr.Report {
 	rb := newReportBuilder()
 	rb.packageName = p.packageName
+	rb.subtestMode = p.subtestMode
 	if p.timestampFunc != nil {
 		rb.timestampFunc = p.timestampFunc
 	}

parser/gotest/gotest_test.go

@@ -12,7 +12,8 @@ import (
 )
 
 var (
-	testTimestamp = time.Date(2022, 1, 1, 0, 0, 0, 0, time.UTC)
+	testTimestamp     = time.Date(2022, 1, 1, 0, 0, 0, 0, time.UTC)
+	testTimestampFunc = func() time.Time { return testTimestamp }
 )
 
 type parseLineTest struct {
@@ -308,9 +309,101 @@ func TestReport(t *testing.T) {
 		},
 	}
 
-	parser := NewParser(TimestampFunc(func() time.Time { return testTimestamp }))
+	parser := NewParser(TimestampFunc(testTimestampFunc))
 	got := parser.report(events)
 	if diff := cmp.Diff(want, got); diff != "" {
 		t.Errorf("FromEvents report incorrect, diff (-want, +got):\n%v", diff)
 	}
 }
+
+func TestSubtestModes(t *testing.T) {
+	events := []Event{
+		{Type: "run_test", Name: "TestParent"},
+		{Type: "output", Data: "TestParent output"},
+		{Type: "run_test", Name: "TestParent/Subtest#1"},
+		{Type: "output", Data: "Subtest#1 output"},
+		{Type: "run_test", Name: "TestParent/Subtest#2"},
+		{Type: "output", Data: "Subtest#2 output"},
+		{Type: "end_test", Name: "TestParent", Result: "PASS", Duration: 1 * time.Millisecond},
+		{Type: "end_test", Name: "TestParent/Subtest#1", Result: "FAIL", Duration: 2 * time.Millisecond},
+		{Type: "end_test", Name: "TestParent/Subtest#2", Result: "PASS", Duration: 3 * time.Millisecond},
+		{Type: "summary", Result: "FAIL", Name: "package/name", Duration: 1 * time.Millisecond},
+	}
+
+	tests := []struct {
+		name string
+		mode SubtestMode
+		want gtr.Report
+	}{
+		{
+			name: "ignore subtest parent results",
+			mode: IgnoreParentResults,
+			want: gtr.Report{
+				Packages: []gtr.Package{
+					{
+						Name:      "package/name",
+						Duration:  1 * time.Millisecond,
+						Timestamp: testTimestamp,
+						Tests: []gtr.Test{
+							{
+								Name:     "TestParent",
+								Duration: 1 * time.Millisecond,
+								Result:   gtr.Pass,
+								Output:   []string{"TestParent output"},
+							},
+							{
+								Name:     "TestParent/Subtest#1",
+								Duration: 2 * time.Millisecond,
+								Result:   gtr.Fail,
+								Output:   []string{"Subtest#1 output"},
+							},
+							{
+								Name:     "TestParent/Subtest#2",
+								Duration: 3 * time.Millisecond,
+								Result:   gtr.Pass,
+								Output:   []string{"Subtest#2 output"},
+							},
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "exclude subtest parents",
+			mode: ExcludeParents,
+			want: gtr.Report{
+				Packages: []gtr.Package{
+					{
+						Name:      "package/name",
+						Duration:  1 * time.Millisecond,
+						Timestamp: testTimestamp,
+						Tests: []gtr.Test{
+							{
+								Name:     "TestParent/Subtest#1",
+								Duration: 2 * time.Millisecond,
+								Result:   gtr.Fail,
+								Output:   []string{"Subtest#1 output"},
+							},
+							{
+								Name:     "TestParent/Subtest#2",
+								Duration: 3 * time.Millisecond,
+								Result:   gtr.Pass,
+								Output:   []string{"Subtest#2 output"},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			parser := NewParser(TimestampFunc(testTimestampFunc), SetSubtestMode(test.mode))
+			got := parser.report(events)
+			if diff := cmp.Diff(test.want, got); diff != "" {
+				t.Errorf("Invalid report created from events, diff (-want, +got):\n%v", diff)
+			}
+		})
+	}
+}

parser/gotest/report_builder.go

@@ -1,6 +1,8 @@
 package gotest
 
 import (
+	"fmt"
+	"strings"
 	"time"
 
 	"github.com/jstemmer/go-junit-report/v2/gtr"
@@ -22,13 +24,15 @@ type reportBuilder struct {
 	runErrors   map[int]gtr.Error
 
 	// state
-	nextID   int      // next free unused id
-	lastID   int      // most recently created id
-	output   []string // output that does not belong to any test
-	coverage float64  // coverage percentage
+	nextID    int              // next free unused id
+	lastID    int              // most recently created id
+	output    []string         // output that does not belong to any test
+	coverage  float64          // coverage percentage
+	parentIDs map[int]struct{} // set of test id's that contain subtests
 
 	// options
 	packageName   string
+	subtestMode   SubtestMode
 	timestampFunc func() time.Time
 }
 
@@ -40,6 +44,7 @@ func newReportBuilder() *reportBuilder {
 		buildErrors:   make(map[int]gtr.Error),
 		runErrors:     make(map[int]gtr.Error),
 		nextID:        1,
+		parentIDs:     make(map[int]struct{}),
 		timestampFunc: time.Now,
 	}
 }
@@ -71,6 +76,9 @@ func (b *reportBuilder) Build() gtr.Report {
 // CreateTest adds a test with the given name to the report, and marks it as
 // active.
 func (b *reportBuilder) CreateTest(name string) {
+	if parentID, ok := b.findTestParentID(name); ok {
+		b.parentIDs[parentID] = struct{}{}
+	}
 	b.tests[b.newID()] = gtr.Test{Name: name}
 }
 
@@ -233,6 +241,14 @@ func (b *reportBuilder) CreatePackage(name, result string, duration time.Duratio
 	var benchmarks []gtr.Benchmark
 	for id := 1; id < b.nextID; id++ {
 		if t, ok := b.tests[id]; ok {
+			if b.isParent(id) {
+				if b.subtestMode == IgnoreParentResults {
+					t.Result = gtr.Pass
+				} else if b.subtestMode == ExcludeParents {
+					fmt.Printf("excluding test %v\n", t.Name)
+					continue
+				}
+			}
 			tests = append(tests, t)
 			continue
 		}
@@ -255,6 +271,7 @@ func (b *reportBuilder) CreatePackage(name, result string, duration time.Duratio
 	b.coverage = 0
 	b.tests = make(map[int]gtr.Test)
 	b.benchmarks = make(map[int]gtr.Benchmark)
+	b.parentIDs = make(map[int]struct{})
 }
 
 // Coverage sets the code coverage percentage.
@@ -291,14 +308,37 @@ func (b *reportBuilder) findTest(name string) (int, bool) {
 	if t, ok := b.tests[b.lastID]; ok && t.Name == name {
 		return b.lastID, true
 	}
-	for id := len(b.tests); id >= 0; id-- {
-		if b.tests[id].Name == name {
-			return id, true
+	for i := b.nextID; i >= 0; i-- {
+		if test, ok := b.tests[i]; ok && test.Name == name {
+			return i, true
 		}
 	}
 	return 0, false
 }
 
+func (b *reportBuilder) findTestParentID(name string) (int, bool) {
+	parent := dropLastSegment(name)
+	for parent != "" {
+		if id, ok := b.findTest(parent); ok {
+			return id, true
+		}
+		parent = dropLastSegment(parent)
+	}
+	return 0, false
+}
+
+func (b *reportBuilder) isParent(id int) bool {
+	_, ok := b.parentIDs[id]
+	return ok
+}
+
+func dropLastSegment(name string) string {
+	if idx := strings.LastIndexByte(name, '/'); idx >= 0 {
+		return name[:idx]
+	}
+	return ""
+}
+
 // findBenchmark returns the id of the most recently created benchmark with the
 // given name if it exists.
 func (b *reportBuilder) findBenchmark(name string) (int, bool) {