diff --git a/cmd/txtpbfmt/fmt.go b/cmd/txtpbfmt/fmt.go
index 304f0a9..debe63d 100644
--- a/cmd/txtpbfmt/fmt.go
+++ b/cmd/txtpbfmt/fmt.go
@@ -6,7 +6,7 @@ import (
 	"bufio"
 	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 	"strings"
 
@@ -39,9 +39,9 @@ const stdinPlaceholderPath = "<stdin>"
 
 func read(path string) ([]byte, error) {
 	if path == stdinPlaceholderPath {
-		return ioutil.ReadAll(bufio.NewReader(os.Stdin))
+		return io.ReadAll(bufio.NewReader(os.Stdin))
 	}
-	return ioutil.ReadFile(path)
+	return os.ReadFile(path)
 }
 
 func errorf(format string, args ...interface{}) {
@@ -119,7 +119,7 @@ func write(path string, content, newContent []byte) error {
 		fmt.Println(string(newContent))
 		return nil
 	}
-	if err := ioutil.WriteFile(path, newContent, 0664); err != nil {
+	if err := os.WriteFile(path, newContent, 0664); err != nil {
 		return err
 	}
 	return nil
diff --git a/unquote/unquote_test.go b/unquote/unquote_test.go
index 30844a9..480d574 100644
--- a/unquote/unquote_test.go
+++ b/unquote/unquote_test.go
@@ -88,6 +88,62 @@ func TestErrorHandling(t *testing.T) {
 			in:      "`foo`",
 			wantErr: "invalid quote character `",
 		},
+		{
+			in:      `"foo\x"`,
+			wantErr: `\x requires 2 following digits`,
+		},
+		{
+			in:      `"foo\xH"`,
+			wantErr: `\x requires 2 following digits`,
+		},
+		{
+			in:      `"foo\xHH"`,
+			wantErr: `\xHH contains non-hexadecimal digits`,
+		},
+		{
+			in:      `"foo\u"`,
+			wantErr: `\u requires 4 following digits`,
+		},
+		{
+			in:      `"foo\uH"`,
+			wantErr: `\u requires 4 following digits`,
+		},
+		{
+			in:      `"foo\uHHHH"`,
+			wantErr: `\uHHHH contains non-hexadecimal digits`,
+		},
+		{
+			in:      `"foo\U"`,
+			wantErr: `\U requires 8 following digits`,
+		},
+		{
+			in:      `"foo\UH"`,
+			wantErr: `\U requires 8 following digits`,
+		},
+		{
+			in:      `"foo\UHHHHHHHH"`,
+			wantErr: `\UHHHHHHHH contains non-hexadecimal digits`,
+		},
+		{
+			in:      `"foo\UFFFFFFFF"`,
+			wantErr: `\UFFFFFFFF is not a valid Unicode code point`,
+		},
+		{
+			in:      `"foo\0"`,
+			wantErr: `\0 requires 2 following digits`,
+		},
+		{
+			in:      `"foo\0H"`,
+			wantErr: `\0 requires 2 following digits`,
+		},
+		{
+			in:      `"foo\0HH"`,
+			wantErr: `\0HH contains non-octal digits`,
+		},
+		{
+			in:      `"foo\y"`,
+			wantErr: `unknown escape \y`,
+		},
 	}
 
 	for _, input := range inputs {
@@ -97,10 +153,55 @@ func TestErrorHandling(t *testing.T) {
 		if err == nil || !strings.Contains(err.Error(), input.wantErr) {
 			t.Errorf("Unquote(%s) got %v, want err to contain %q", input.in, err, input.wantErr)
 		}
+	}
+}
 
-		_, _, err = Raw(node)
+func TestErrorHandlingRaw(t *testing.T) {
+	inputs := []struct {
+		in      string
+		wantErr string
+	}{
+		{
+			in:      `"value`,
+			wantErr: "unmatched quote",
+		},
+		{
+			in:      `"`,
+			wantErr: "not a quoted string",
+		},
+		{
+			in:      "`foo`",
+			wantErr: "invalid quote character `",
+		},
+	}
+
+	for _, input := range inputs {
+		node := &ast.Node{Name: "name", Values: []*ast.Value{{Value: input.in}}}
+
+		_, _, err := Raw(node)
 		if err == nil || !strings.Contains(err.Error(), input.wantErr) {
 			t.Errorf("Raw(%s) got %v, want err to contain %q", input.in, err, input.wantErr)
 		}
 	}
 }
+
+func TestErrorHandlingMisc(t *testing.T) {
+	inputs := []struct {
+		in      string
+		wantErr string
+	}{
+		{
+			in:      `"value`,
+			wantErr: "unmatched quote",
+		},
+	}
+
+	for _, input := range inputs {
+		node := &ast.Node{Name: "name", Values: []*ast.Value{{Value: input.in}}}
+
+		_, _, err := Unquote(node)
+		if err == nil || !strings.Contains(err.Error(), input.wantErr) {
+			t.Errorf("Unquote(%s) got %v, want err to contain %q", input.in, err, input.wantErr)
+		}
+	}
+}