1 files changed, 140 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/base/hashdebug_test.go b/src/cmd/compile/internal/base/hashdebug_test.go
new file mode 100644
index 0000000..62ef2ed
--- /dev/null
+++ b/src/cmd/compile/internal/base/hashdebug_test.go
@@ -0,0 +1,140 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package base
+
+import (
+	"bytes"
+	"internal/bisect"
+	"strings"
+	"testing"
+)
+
+func TestHashDebugGossahashY(t *testing.T) {
+	hd := NewHashDebug("GOSSAHASH", "y", new(bytes.Buffer))
+	if hd == nil {
+		t.Errorf("NewHashDebug should not return nil for GOSSASHASH=y")
+	}
+	if !hd.MatchPkgFunc("anything", "anyfunc", nil) {
+		t.Errorf("NewHashDebug should return yes for everything for GOSSASHASH=y")
+	}
+}
+
+func TestHashDebugGossahashN(t *testing.T) {
+	hd := NewHashDebug("GOSSAHASH", "n", new(bytes.Buffer))
+	if hd == nil {
+		t.Errorf("NewHashDebug should not return nil for GOSSASHASH=n")
+	}
+	if hd.MatchPkgFunc("anything", "anyfunc", nil) {
+		t.Errorf("NewHashDebug should return no for everything for GOSSASHASH=n")
+	}
+}
+
+func TestHashDebugGossahashEmpty(t *testing.T) {
+	hd := NewHashDebug("GOSSAHASH", "", nil)
+	if hd != nil {
+		t.Errorf("NewHashDebug should return nil for GOSSASHASH=\"\"")
+	}
+}
+
+func TestHashDebugMagic(t *testing.T) {
+	hd := NewHashDebug("FOOXYZZY", "y", nil)
+	hd0 := NewHashDebug("FOOXYZZY0", "n", nil)
+	if hd == nil {
+		t.Errorf("NewHashDebug should have succeeded for FOOXYZZY")
+	}
+	if hd0 == nil {
+		t.Errorf("NewHashDebug should have succeeded for FOOXYZZY0")
+	}
+}
+
+func TestHash(t *testing.T) {
+	h0 := bisect.Hash("bar", "0")
+	h1 := bisect.Hash("bar", "1")
+	t.Logf(`These values are used in other tests: Hash("bar", "0")=%#64b, Hash("bar", "1")=%#64b`, h0, h1)
+	if h0 == h1 {
+		t.Errorf("Hashes 0x%x and 0x%x should differ", h0, h1)
+	}
+}
+
+func TestHashMatch(t *testing.T) {
+	b := new(bytes.Buffer)
+	hd := NewHashDebug("GOSSAHASH", "v1110", b)
+	check := hd.MatchPkgFunc("bar", "0", func() string { return "note" })
+	msg := b.String()
+	t.Logf("message was '%s'", msg)
+	if !check {
+		t.Errorf("GOSSAHASH=1110 should have matched for 'bar', '0'")
+	}
+	wantPrefix(t, msg, "bar.0: note [bisect-match ")
+	wantContains(t, msg, "\nGOSSAHASH triggered bar.0: note ")
+}
+
+func TestYMatch(t *testing.T) {
+	b := new(bytes.Buffer)
+	hd := NewHashDebug("GOSSAHASH", "vy", b)
+	check := hd.MatchPkgFunc("bar", "0", nil)
+	msg := b.String()
+	t.Logf("message was '%s'", msg)
+	if !check {
+		t.Errorf("GOSSAHASH=y should have matched for 'bar', '0'")
+	}
+	wantPrefix(t, msg, "bar.0 [bisect-match ")
+	wantContains(t, msg, "\nGOSSAHASH triggered bar.0 010100100011100101011110")
+}
+
+func TestNMatch(t *testing.T) {
+	b := new(bytes.Buffer)
+	hd := NewHashDebug("GOSSAHASH", "vn", b)
+	check := hd.MatchPkgFunc("bar", "0", nil)
+	msg := b.String()
+	t.Logf("message was '%s'", msg)
+	if check {
+		t.Errorf("GOSSAHASH=n should NOT have matched for 'bar', '0'")
+	}
+	wantPrefix(t, msg, "bar.0 [DISABLED] [bisect-match ")
+	wantContains(t, msg, "\nGOSSAHASH triggered bar.0 [DISABLED] 010100100011100101011110")
+}
+
+func TestHashNoMatch(t *testing.T) {
+	b := new(bytes.Buffer)
+	hd := NewHashDebug("GOSSAHASH", "01110", b)
+	check := hd.MatchPkgFunc("bar", "0", nil)
+	msg := b.String()
+	t.Logf("message was '%s'", msg)
+	if check {
+		t.Errorf("GOSSAHASH=001100 should NOT have matched for 'bar', '0'")
+	}
+	if msg != "" {
+		t.Errorf("Message should have been empty, instead %s", msg)
+	}
+
+}
+
+func TestHashSecondMatch(t *testing.T) {
+	b := new(bytes.Buffer)
+	hd := NewHashDebug("GOSSAHASH", "01110/11110", b)
+
+	check := hd.MatchPkgFunc("bar", "0", nil)
+	msg := b.String()
+	t.Logf("message was '%s'", msg)
+	if !check {
+		t.Errorf("GOSSAHASH=001100, GOSSAHASH0=0011 should have matched for 'bar', '0'")
+	}
+	wantContains(t, msg, "\nGOSSAHASH0 triggered bar")
+}
+
+func wantPrefix(t *testing.T, got, want string) {
+	t.Helper()
+	if !strings.HasPrefix(got, want) {
+		t.Errorf("want prefix %q, got:\n%s", want, got)
+	}
+}
+
+func wantContains(t *testing.T, got, want string) {
+	t.Helper()
+	if !strings.Contains(got, want) {
+		t.Errorf("want contains %q, got:\n%s", want, got)
+	}
+}