Run 'go fix' to modernize code

gitdiff/apply.go

@@ -61,7 +61,7 @@ type fragLineNum int
 
 // applyError creates a new *ApplyError wrapping err or augments the information
 // in err with args if it is already an *ApplyError. Returns nil if err is nil.
-func applyError(err error, args ...interface{}) error {
+func applyError(err error, args ...any) error {
 	if err == nil {
 		return nil
 	}

gitdiff/apply_test.go

@@ -165,7 +165,7 @@ func TestApplyFile(t *testing.T) {
 
 type applyTest struct {
 	Files applyFiles
-	Err   interface{}
+	Err   any
 }
 
 func (at applyTest) run(t *testing.T, apply func(io.Writer, io.ReaderAt, *File) error) {

gitdiff/assert_test.go

@@ -6,7 +6,7 @@ import (
 	"testing"
 )
 
-func assertError(t *testing.T, expected interface{}, actual error, action string) {
+func assertError(t *testing.T, expected any, actual error, action string) {
 	if actual == nil {
 		t.Fatalf("expected error %s, but got nil", action)
 	}

gitdiff/io_test.go

@@ -87,7 +87,7 @@ func TestLineReaderAt(t *testing.T) {
 
 			output := make([][]byte, test.Count)
 			for i := 0; i < test.Count; i++ {
-				output[i] = []byte(fmt.Sprintf(lineTemplate, test.Offset+int64(i)))
+				output[i] = fmt.Appendf(nil, lineTemplate, test.Offset+int64(i))
 			}
 
 			r := &lineReaderAt{r: bytes.NewReader(input.Bytes())}

gitdiff/parser.go

@@ -137,6 +137,6 @@ func (p *parser) Line(delta uint) string {
 }
 
 // Errorf generates an error and appends the current line information.
-func (p *parser) Errorf(delta int64, msg string, args ...interface{}) error {
+func (p *parser) Errorf(delta int64, msg string, args ...any) error {
 	return fmt.Errorf("gitdiff: line %d: %s", p.lineno+delta, fmt.Sprintf(msg, args...))
 }

gitdiff/patch_header.go

@@ -186,9 +186,9 @@ func ParsePatchHeader(header string, options ...PatchHeaderOption) (*PatchHeader
 	}
 
 	var firstLine, rest string
-	if idx := strings.IndexByte(header, '\n'); idx >= 0 {
-		firstLine = header[:idx]
-		rest = header[idx+1:]
+	if before, after, ok := strings.Cut(header, "\n"); ok {
+		firstLine = before
+		rest = after
 	} else {
 		firstLine = header
 		rest = ""
@@ -362,8 +362,8 @@ func parseHeaderMail(mailLine string, r io.Reader, opts patchHeaderOptions) (*Pa
 
 	h := &PatchHeader{}
 
-	if strings.HasPrefix(mailLine, mailHeaderPrefix) {
-		mailLine = strings.TrimPrefix(mailLine, mailHeaderPrefix)
+	if after, ok := strings.CutPrefix(mailLine, mailHeaderPrefix); ok {
+		mailLine = after
 		if i := strings.IndexByte(mailLine, ' '); i > 0 {
 			h.SHA = mailLine[:i]
 		}

gitdiff/patch_header_test.go

@@ -11,7 +11,7 @@ func TestParsePatchDate(t *testing.T) {
 	tests := map[string]struct {
 		Input  string
 		Output time.Time
-		Err    interface{}
+		Err    any
 	}{
 		"default": {
 			Input:  "Thu Apr 9 01:07:06 2020 -0700",
@@ -88,7 +88,7 @@ func TestParsePatchHeader(t *testing.T) {
 		Input   string
 		Options []PatchHeaderOption
 		Header  PatchHeader
-		Err     interface{}
+		Err     any
 	}{
 		"prettyShort": {
 			Input: `commit 61f5cd90bed4d204ee3feb3aa41ee91d4734855b

gitdiff/patch_identity_test.go

@@ -8,7 +8,7 @@ func TestParsePatchIdentity(t *testing.T) {
 	tests := map[string]struct {
 		Input  string
 		Output PatchIdentity
-		Err    interface{}
+		Err    any
 	}{
 		"simple": {
 			Input: "Morton Haypenny <mhaypenny@example.com>",

gitdiff/text.go

@@ -183,10 +183,3 @@ func parseRange(s string) (start int64, end int64, err error) {
 
 	return
 }
-
-func max(a, b int64) int64 {
-	if a > b {
-		return a
-	}
-	return b
-}