Deduplicate fuzz cases on the frontend before they are displayed.

fuzzer/go/deduplicator/deduplicator_test.go

Index: fuzzer/go/deduplicator/deduplicator_test.go
diff --git a/fuzzer/go/deduplicator/deduplicator_test.go b/fuzzer/go/deduplicator/deduplicator_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..8a86755bd960f8e8ea8cf94b6eea803b63812c26
--- /dev/null
+++ b/fuzzer/go/deduplicator/deduplicator_test.go
@@ -0,0 +1,200 @@
+package deduplicator
+
+import (
+	"testing"
+
+	"go.skia.org/infra/fuzzer/go/frontend/data"
+)
+
+func TestSimpleDeduplication(t *testing.T) {
+	d := New()
+	r1 := data.MockReport("skpicture", "aaaa")
+	r2 := data.MockReport("skpicture", "bbbb")
+	// mock report ffff and aaaa are the same, except for the name.
+	r3 := data.MockReport("skpicture", "ffff")
+	if !d.IsUnique(r1) {
+		t.Errorf("The deduplicator has not seen %#v, but said it has", r1)
+	}
+	if !d.IsUnique(r2) {
+		t.Errorf("The deduplicator has not seen %#v, but said it has", r2)
+	}
+	if d.IsUnique(r1) {
+		t.Errorf("Should not have said %#v was unique, it just saw it.", r1)
+	}
+	if d.IsUnique(r3) {
+		t.Errorf("Should not have said %#v was unique, it just saw something like it.", r3)
+	}
+}
+
+func TestUnknownStacktraces(t *testing.T) {
+	d := New()
+	// mock report ee has no stacktrace for either.  It should not be considered a duplicate, ever.
+	r1 := data.MockReport("skpicture", "eeee")
+	if !d.IsUnique(r1) {
+		t.Errorf("The deduplicator has not seen %#v, but said it has", r1)
+	}
+	if !d.IsUnique(r1) {
+		t.Errorf("Should not have said %#v was not unique, unknown stacktraces don't count.", r1)
+	}
+}
+
+func TestKey(t *testing.T) {
+	// r1 is a report with 6 and 7 stacktrace frames for Debug/Release
+	r1 := makeReport()
+	r1.DebugStackTrace.Frames = append(r1.DebugStackTrace.Frames, data.StackTraceFrame{})
+	r1.ReleaseStackTrace.Frames = append(r1.DebugStackTrace.Frames, data.StackTraceFrame{})
+
+	k1 := key(r1)
+	k2 := key(r1)
+	if k1 != k2 {
+		t.Errorf("Keys should be deterministic\n%s != %s", k1, k2)
+	}
+	if n := len(r1.DebugStackTrace.Frames); n != _MAX_STACKTRACE_LINES+1 {
+		t.Errorf("key() should not have changed the report - it now has %d frames instead of 6", n)
+		t.Errorf(r1.DebugStackTrace.String())
+	}
+	if n := len(r1.ReleaseStackTrace.Frames); n != _MAX_STACKTRACE_LINES+2 {
+		t.Errorf("key() should not have changed the report - it now has %d frames instead of 7", n)
+		t.Errorf(r1.DebugStackTrace.String())
+	}
+	if frame := r1.DebugStackTrace.Frames[0]; frame.LineNumber == 0 {
+		t.Errorf("key() should not have changed the report - it now has the wrong line number at index 0: %s", r1.DebugStackTrace.String())
+	}
+	if frame := r1.ReleaseStackTrace.Frames[0]; frame.LineNumber == 0 {
+		t.Errorf("key() should not have changed the report - it now has the wrong line number at index 0: %s", r1.ReleaseStackTrace.String())
+	}
+}
+
+func TestLinesOfStacktrace(t *testing.T) {
+	d := New()
+	r1 := makeReport()
+	r2 := makeReport()
+	r2.DebugStackTrace.Frames = append(r2.DebugStackTrace.Frames, data.StackTraceFrame{})
+	r3 := makeReport()
+	r3.ReleaseStackTrace.Frames = append(r3.ReleaseStackTrace.Frames, data.StackTraceFrame{})
+	if !d.IsUnique(r1) {
+		t.Errorf("The deduplicator has not seen %#v, but said it has", r1)
+	}
+	if d.IsUnique(r2) {
+		t.Errorf("Should not have said %#v was unique, it just saw something with the same top %d stacktraces.", r2, _MAX_STACKTRACE_LINES)
+		t.Errorf("Debug stacktraces: \n%s\n\n%s", r1.DebugStackTrace.String(), r2.DebugStackTrace.String())
+		t.Errorf("Release stacktraces: \n%s\n\n%s", r1.ReleaseStackTrace.String(), r2.ReleaseStackTrace.String())
+	}
+	if d.IsUnique(r3) {
+		t.Errorf("Should not have said %#v was unique, it just saw something with the same top %d stacktraces.", r3, _MAX_STACKTRACE_LINES)
+		t.Errorf("Debug stacktraces: \n%s\n\n%s", r1.DebugStackTrace.String(), r3.DebugStackTrace.String())
+		t.Errorf("Release stacktraces: \n%s\n\n%s", r1.ReleaseStackTrace.String(), r3.ReleaseStackTrace.String())
+	}
+}
+
+func TestLineNumbers(t *testing.T) {
+	d := New()
+	r1 := makeReport()
+	r2 := makeReport()
+	r2.DebugStackTrace.Frames[0].LineNumber = 9999
+	r3 := makeReport()
+	r3.ReleaseStackTrace.Frames[0].LineNumber = 9999
+	if !d.IsUnique(r1) {
+		t.Errorf("The deduplicator has not seen %#v, but said it has", r1)
+	}
+	if d.IsUnique(r2) {
+		t.Errorf("Should not have said %#v was unique, it just saw something with the same top %d stacktraces, not counting line numbers.", r2, _MAX_STACKTRACE_LINES)
+		t.Errorf("Debug stacktraces: \n%s\n\n%s", r1.DebugStackTrace.String(), r2.DebugStackTrace.String())
+		t.Errorf("Release stacktraces: \n%s\n\n%s", r1.ReleaseStackTrace.String(), r2.ReleaseStackTrace.String())
+	}
+	if d.IsUnique(r3) {
+		t.Errorf("Should not have said %#v was unique, it just saw something with the same top %d stacktraces, not counting line numbers.", r3, _MAX_STACKTRACE_LINES)
+		t.Errorf("Debug stacktraces: \n%s\n\n%s", r1.DebugStackTrace.String(), r3.DebugStackTrace.String())
+		t.Errorf("Release stacktraces: \n%s\n\n%s", r1.ReleaseStackTrace.String(), r3.ReleaseStackTrace.String())
+	}
+}
+
+func TestFlags(t *testing.T) {
+	d := New()
+	r1 := makeReport()
+	r2 := makeReport()
+	r2.ReleaseFlags = makeFlags(4, 2)
+	r3 := makeReport()
+	r3.DebugFlags = makeFlags(4, 2)
+	if !d.IsUnique(r1) {
+		t.Errorf("The deduplicator has not seen %#v, but said it has", r1)
+	}
+	if !d.IsUnique(r2) {
+		t.Errorf("The deduplicator has not seen %#v, but said it has", r2)
+		t.Errorf("Release flags: \n%s\n\n%s", r1.ReleaseFlags, r2.ReleaseFlags)
+	}
+	if !d.IsUnique(r3) {
+		t.Errorf("The deduplicator has not seen %#v, but said it has", r3)
+		t.Errorf("Release flags: \n%s\n\n%s", r1.ReleaseFlags, r3.ReleaseFlags)
+	}
+}
+
+func TestCategory(t *testing.T) {
+	d := New()
+	r1 := makeReport()
+	r2 := makeReport()
+	r2.FuzzCategory = "something else"
+	if !d.IsUnique(r1) {
+		t.Errorf("The deduplicator has not seen %#v, but said it has", r1)
+	}
+	if !d.IsUnique(r2) {
+		t.Errorf("The deduplicator has not seen %#v, but said it has", r2)
+	}
+}
+
+func TestOther(t *testing.T) {
+	d := New()
+	r1 := makeReport()
+	r1.DebugFlags = append(r1.DebugFlags, "Other")
+	r2 := makeReport()
+	r2.ReleaseFlags = append(r2.ReleaseFlags, "Other")
+	if !d.IsUnique(r1) {
+		t.Errorf("The deduplicator has not seen %#v, but said it has", r1)
+	}
+	if !d.IsUnique(r1) {
+		t.Errorf("The deduplicator should have said %#v was unique.  The flag 'Other' should not be filtered.", r1)
+	}
+
+	if !d.IsUnique(r2) {
+		t.Errorf("The deduplicator has not seen %#v, but said it has", r2)
+	}
+	if !d.IsUnique(r2) {
+		t.Errorf("The deduplicator should have said %#v was unique.  The flag 'Other' should not be filtered.", r2)
+	}
+}
+
+// Makes a report with the smallest stacktraces distinguishable by the deduplicator, 3 debug
+// flags, 3 release flags and a standard name and category
+func makeReport() data.FuzzReport {
+	ds := makeStacktrace(0)
+	rs := makeStacktrace(3)
+	df := makeFlags(0, 3)
+	rf := makeFlags(1, 2)
+
+	return data.FuzzReport{
+		DebugStackTrace:   ds,
+		ReleaseStackTrace: rs,
+		DebugFlags:        df,
+		ReleaseFlags:      rf,
+		FuzzName:          "doesn't matter",
+		FuzzCategory:      "api",
+	}
+}
+
+var names = []string{"alpha", "beta", "gamma", "delta", "epsilon", "zeta", "theta", "iota", "kappa", "lambda", "mu"}
+
+func makeStacktrace(start int) data.StackTrace {
+	st := data.StackTrace{}
+	r := start
+	n := len(names)
+	for i := 0; i < _MAX_STACKTRACE_LINES; i++ {
+		a, b, c, d := r%n, (r+1)%n, (r+2)%n, (r+3)%n
+		st.Frames = append(st.Frames, data.FullStackFrame(names[a], names[b], names[c], d))
+		r = (r + 4) % n
+	}
+	return st
+}
+
+func makeFlags(start, count int) []string {
+	return names[start:(start + count)]
+}