1 files changed, 67 insertions, 0 deletions
diff --git a/src/internal/pkgbits/pkgbits_test.go b/src/internal/pkgbits/pkgbits_test.go
new file mode 100644
index 0000000000..a5f93c7e8e
--- /dev/null
+++ b/src/internal/pkgbits/pkgbits_test.go
@@ -0,0 +1,67 @@
+// Copyright 2024 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 pkgbits_test
+
+import (
+	"internal/pkgbits"
+	"strings"
+	"testing"
+)
+
+func TestRoundTrip(t *testing.T) {
+	pw := pkgbits.NewPkgEncoder(-1)
+	w := pw.NewEncoder(pkgbits.RelocMeta, pkgbits.SyncPublic)
+	w.Flush()
+
+	var b strings.Builder
+	_ = pw.DumpTo(&b)
+	input := b.String()
+
+	pr := pkgbits.NewPkgDecoder("package_id", input)
+	r := pr.NewDecoder(pkgbits.RelocMeta, pkgbits.PublicRootIdx, pkgbits.SyncPublic)
+
+	if r.Version() != w.Version() {
+		t.Errorf("Expected reader version %q to be the writer version %q", r.Version(), w.Version())
+	}
+}
+
+// Type checker to enforce that know V* have the constant values they must have.
+var _ [0]bool = [pkgbits.V0]bool{}
+var _ [1]bool = [pkgbits.V1]bool{}
+
+func TestVersions(t *testing.T) {
+	type vfpair struct {
+		v pkgbits.Version
+		f pkgbits.Field
+	}
+
+	// has field tests
+	for _, c := range []vfpair{
+		{pkgbits.V1, pkgbits.Flags},
+		{pkgbits.V2, pkgbits.Flags},
+		{pkgbits.V0, pkgbits.HasInit},
+		{pkgbits.V1, pkgbits.HasInit},
+		{pkgbits.V0, pkgbits.DerivedFuncInstance},
+		{pkgbits.V1, pkgbits.DerivedFuncInstance},
+		{pkgbits.V2, pkgbits.AliasTypeParamNames},
+	} {
+		if !c.v.Has(c.f) {
+			t.Errorf("Expected version %v to have field %v", c.v, c.f)
+		}
+	}
+
+	// does not have field tests
+	for _, c := range []vfpair{
+		{pkgbits.V0, pkgbits.Flags},
+		{pkgbits.V2, pkgbits.HasInit},
+		{pkgbits.V2, pkgbits.DerivedFuncInstance},
+		{pkgbits.V0, pkgbits.AliasTypeParamNames},
+		{pkgbits.V1, pkgbits.AliasTypeParamNames},
+	} {
+		if c.v.Has(c.f) {
+			t.Errorf("Expected version %v to not have field %v", c.v, c.f)
+		}
+	}
+}