diff --git a/tools/lib/report/report.go b/tools/lib/report/report.go
index 36c1ca8..49e8875 100644
--- a/tools/lib/report/report.go
+++ b/tools/lib/report/report.go
@@ -80,6 +80,7 @@ func ParseAttestation(b []byte, inform string) (*spb.Attestation, error) {
 				return nil, fmt.Errorf("could not parse as textproto: %v", multierr.Append(aerr, rerr))
 			}
 		}
+		return result, nil
 	default:
 		return nil, fmt.Errorf("unknown inform: %q", inform)
 	}
diff --git a/tools/lib/report/report_test.go b/tools/lib/report/report_test.go
new file mode 100644
index 0000000..8746502
--- /dev/null
+++ b/tools/lib/report/report_test.go
@@ -0,0 +1,197 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package report
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"path"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/google/go-sev-guest/abi"
+	"github.com/google/go-sev-guest/client"
+	spb "github.com/google/go-sev-guest/proto/sevsnp"
+	test "github.com/google/go-sev-guest/testing"
+	"google.golang.org/protobuf/encoding/prototext"
+	"google.golang.org/protobuf/proto"
+)
+
+var qp client.QuoteProvider
+var mu sync.Once
+
+type reports struct {
+	attestation *spb.Attestation
+	bincerts    []byte
+	binreport   []byte
+	protocerts  []byte
+	protoreport []byte
+	textcerts   []byte
+	textreport  []byte
+}
+
+var input *reports
+
+func initDevice() {
+	now := time.Date(2022, time.May, 3, 9, 0, 0, 0, time.UTC)
+	tests := test.TestCases()
+	ones32 := make([]byte, 32)
+	for i := range ones32 {
+		ones32[i] = 1
+	}
+	opts := &test.DeviceOptions{Now: now}
+	tcqp, err := test.TcQuoteProvider(tests, opts)
+	if err != nil {
+		panic(fmt.Sprintf("failed to create test device: %v", err))
+	}
+	qp = tcqp
+
+	var zeros [abi.ReportDataSize]byte
+	bincerts, err := qp.GetRawQuote(zeros)
+	if err != nil {
+		panic(fmt.Errorf("mock failed to quote: %v", err))
+	}
+	if len(bincerts) < abi.ReportSize+abi.CertTableEntrySize {
+		panic("mock failed to return cert table")
+	}
+	binreport := bincerts[:abi.ReportSize]
+	attestation, err := ParseAttestation(bincerts, "bin")
+	if err != nil {
+		panic(fmt.Errorf("marshal failure: %v", err))
+	}
+	protocerts, err := proto.Marshal(attestation)
+	if err != nil {
+		panic(fmt.Errorf("marshal failure: %v", err))
+	}
+	protoreport, err := proto.Marshal(attestation.Report)
+	if err != nil {
+		panic(fmt.Errorf("marshal failure: %v", err))
+	}
+	textcerts, err := prototext.MarshalOptions{Multiline: true, Indent: "  "}.Marshal(attestation)
+	if err != nil {
+		panic(fmt.Errorf("marshal failure: %v", err))
+	}
+	textreport, err := prototext.MarshalOptions{Multiline: true, Indent: "  "}.Marshal(attestation.Report)
+	if err != nil {
+		panic(fmt.Errorf("marshal failure: %v", err))
+	}
+	input = &reports{
+		attestation: attestation,
+		bincerts:    bincerts,
+		binreport:   binreport,
+		protocerts:  protocerts,
+		protoreport: protoreport,
+		textcerts:   textcerts,
+		textreport:  textreport,
+	}
+}
+
+func TestParseAttestation(t *testing.T) {
+	mu.Do(initDevice)
+	type testcase struct {
+		input  []byte
+		inform string
+	}
+	good := []testcase{
+		{input.bincerts, "bin"},
+		{input.binreport, "bin"},
+		{input.protocerts, "proto"},
+		{input.protoreport, "proto"},
+		{input.textcerts, "textproto"},
+		{input.textreport, "textproto"},
+	}
+	bad := []testcase{
+		{input.bincerts, "proto"},
+		{input.textcerts, "bin"},
+		{input.protoreport, "textproto"},
+	}
+	for _, tc := range good {
+		if _, err := ParseAttestation(tc.input, tc.inform); err != nil {
+			t.Fatalf("ParseAttestation(_, %q) = _, %v. Expect nil", tc.inform, err)
+		}
+	}
+	for _, tc := range bad {
+		if _, err := ParseAttestation(tc.input, tc.inform); err == nil {
+			t.Fatalf("ParseAttestation(_, %q) = _, nil. Expected an error", tc.inform)
+		}
+	}
+}
+
+func TestReadAttestation(t *testing.T) {
+	mu.Do(initDevice)
+	type testcase struct {
+		input  []byte
+		inform string
+	}
+	good := []testcase{
+		{input.bincerts, "bin"},
+		{input.binreport, "bin"},
+		{input.protocerts, "proto"},
+		{input.protoreport, "proto"},
+		{input.textcerts, "textproto"},
+		{input.textreport, "textproto"},
+	}
+	bad := []testcase{
+		{input.bincerts, "proto"},
+		{input.textcerts, "bin"},
+		{input.protoreport, "textproto"},
+	}
+	for _, tc := range good {
+		p := path.Join(t.TempDir(), "input")
+		if err := os.WriteFile(p, tc.input, 0644); err != nil {
+			t.Fatalf("Could not write test file %q: %v", p, err)
+		}
+		if _, err := ReadAttestation(p, tc.inform); err != nil {
+			t.Fatalf("ParseAttestation(_, %q) = _, %v. Expect nil", tc.inform, err)
+		}
+	}
+	for _, tc := range bad {
+		p := path.Join(t.TempDir(), "input")
+		if err := os.WriteFile(p, tc.input, 0644); err != nil {
+			t.Fatalf("Could not write test file %q: %v", p, err)
+		}
+		if _, err := ReadAttestation(p, tc.inform); err == nil {
+			t.Fatalf("ReadAttestation(_, %q) = _, nil. Expected an error", tc.inform)
+		}
+	}
+}
+
+func TestTransform(t *testing.T) {
+	mu.Do(initDevice)
+	binout, err := Transform(input.attestation, "bin")
+	if err != nil {
+		t.Fatalf("Transform(_, \"bin\") = _, %v. Expect nil.", err)
+	}
+	if !bytes.Equal(binout, input.bincerts) {
+		t.Fatalf("Transform(_, \"bin\") = %v, nil. Expect %v.", binout, input.bincerts)
+	}
+	protoout, err := Transform(input.attestation, "proto")
+	if err != nil {
+		t.Fatalf("Transform(_, \"proto\") = _, %v. Expect nil.", err)
+	}
+	if !bytes.Equal(protoout, input.protocerts) {
+		t.Fatalf("Transform(_, \"proto\") = %v, nil. Expect %v.", protoout, input.protocerts)
+	}
+	textout, err := Transform(input.attestation, "textproto")
+	if err != nil {
+		t.Fatalf("Transform(_, \"textproto\") = _, %v. Expect nil.", err)
+	}
+	if !bytes.Equal(textout, input.textcerts) {
+		t.Fatalf("Transform(_, \"textproto\") = %v, nil. Expect %v.", string(textout), string(input.textcerts))
+	}
+
+}