go-ini · unknwon · May 3, 2026 · May 3, 2026 · May 3, 2026 · May 3, 2026
diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
@@ -37,7 +37,7 @@ jobs:
     name: Test
     strategy:
       matrix:
-        go-version: [1.24.x, 1.25.x]
+        go-version: [1.26.x]
         platform: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.platform }}
     steps:

diff --git a/.golangci.yml b/.golangci.yml
@@ -6,11 +6,6 @@ linters:
     - unconvert
     - unparam
   settings:
-    govet:
-      disable:
-        # printf: non-constant format string in call to fmt.Errorf (govet)
-        # showing up since golangci-lint version 1.60.1
-        - printf
     nakedret:
       max-func-lines: 0 # Disallow any unnamed return statement
   exclusions:

diff --git a/data_source.go b/data_source.go
@@ -18,7 +18,6 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 )
 
@@ -48,7 +47,7 @@ type sourceData struct {
 }
 
 func (s *sourceData) ReadCloser() (io.ReadCloser, error) {
-	return ioutil.NopCloser(bytes.NewReader(s.data)), nil
+	return io.NopCloser(bytes.NewReader(s.data)), nil
 }
 
 // sourceReadCloser represents an input stream with Close method.
@@ -69,7 +68,7 @@ func parseDataSource(source interface{}) (dataSource, error) {
 	case io.ReadCloser:
 		return &sourceReadCloser{s}, nil
 	case io.Reader:
-		return &sourceReadCloser{ioutil.NopCloser(s)}, nil
+		return &sourceReadCloser{io.NopCloser(s)}, nil
 	default:
 		return nil, fmt.Errorf("error parsing data source: unknown type %q", s)
 	}

diff --git a/file.go b/file.go
@@ -19,7 +19,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"strings"
 	"sync"
@@ -532,7 +531,7 @@ func (f *File) SaveToIndent(filename, indent string) error {
 		return err
 	}
 
-	return ioutil.WriteFile(filename, buf.Bytes(), 0666)
+	return os.WriteFile(filename, buf.Bytes(), 0666)
 }
 
 // SaveTo writes content to file system.

diff --git a/file_test.go b/file_test.go
@@ -16,7 +16,7 @@ package ini
 
 import (
 	"bytes"
-	"io/ioutil"
+	"os"
 	"runtime"
 	"sort"
 	"testing"
@@ -421,10 +421,10 @@ func TestFile_WriteTo(t *testing.T) {
 
 		golden := "testdata/TestFile_WriteTo.golden"
 		if *update {
-			require.NoError(t, ioutil.WriteFile(golden, buf.Bytes(), 0644))
+			require.NoError(t, os.WriteFile(golden, buf.Bytes(), 0644))
 		}
 
-		expected, err := ioutil.ReadFile(golden)
+		expected, err := os.ReadFile(golden)
 		require.NoError(t, err)
 		assert.Equal(t, string(expected), buf.String())
 	})

diff --git a/ini_test.go b/ini_test.go
@@ -17,7 +17,7 @@ package ini
 import (
 	"bytes"
 	"flag"
-	"io/ioutil"
+	"io"
 	"path/filepath"
 	"runtime"
 	"testing"
@@ -58,7 +58,7 @@ func TestLoad(t *testing.T) {
 			"testdata/minimal.ini",
 			[]byte("NAME = ini\nIMPORT_PATH = gopkg.in/%(NAME)s.%(VERSION)s"),
 			bytes.NewReader([]byte(`VERSION = v1`)),
-			ioutil.NopCloser(bytes.NewReader([]byte("[author]\nNAME = Unknwon"))),
+			io.NopCloser(bytes.NewReader([]byte("[author]\nNAME = Unknwon"))),
 		)
 		require.NoError(t, err)
 		require.NotNil(t, f)

diff --git a/key.go b/key.go
@@ -170,7 +170,7 @@ func (k *Key) transformValue(val string) string {
 		}
 
 		// Substitute by new value and take off leading '%(' and trailing ')s'.
-		val = strings.ReplaceAll(val, vr, nk.value)
+		val = strings.ReplaceAll(val, vr, nk.String())
 	}
 	return val
 }

diff --git a/key_test.go b/key_test.go
@@ -183,6 +183,7 @@ func TestKey_Helpers(t *testing.T) {
 					}
 					return in
 				}
+				t.Cleanup(func() { f.ValueMapper = nil })
 				assert.Equal(t, "github.com/go-ini/ini", sec.Key("IMPORT_PATH").String())
 			})
 		})
@@ -635,4 +636,22 @@ bar = %(missing)s
 
 		assert.Equal(t, "%(missing)s", f.Section("foo").Key("bar").String())
 	})
+
+	t.Run("ValueMapper applies to substituted reference value", func(t *testing.T) {
+		f, err := Load([]byte(`
+ACCOUNT_ID = ${LFSD_R2_ACCOUNT_ID}
+ENDPOINT = https://%(ACCOUNT_ID)s.r2.cloudflarestorage.com
+`))
+		require.NoError(t, err)
+		require.NotNil(t, f)
+
+		f.ValueMapper = func(in string) string {
+			if in == "${LFSD_R2_ACCOUNT_ID}" {
+				return "abc123"
+			}
+			return in
+		}
+
+		assert.Equal(t, "https://abc123.r2.cloudflarestorage.com", f.Section("").Key("ENDPOINT").String())
+	})
 }
diff --git a/struct.go b/struct.go
@@ -156,7 +156,7 @@ func wrapStrictError(err error, isStrict bool) error {
 // because we want to use default value that is already assigned to struct.
 func setWithProperType(t reflect.Type, key *Key, field reflect.Value, delim string, allowShadow, isStrict bool) error {
 	vt := t
-	isPtr := t.Kind() == reflect.Ptr
+	isPtr := t.Kind() == reflect.Pointer
 	if isPtr {
 		vt = t.Elem()
 	}
@@ -278,7 +278,7 @@ func parseTagOptions(tag string) (rawName string, omitEmpty bool, allowShadow bo
 // mapToField maps the given value to the matching field of the given section.
 // The sectionIndex is the index (if non unique sections are enabled) to which the value should be added.
 func (s *Section) mapToField(val reflect.Value, isStrict bool, sectionIndex int, sectionName string) error {
-	if val.Kind() == reflect.Ptr {
+	if val.Kind() == reflect.Pointer {
 		val = val.Elem()
 	}
 	typ := val.Type()
@@ -299,8 +299,8 @@ func (s *Section) mapToField(val reflect.Value, isStrict bool, sectionIndex int,
 		}
 
 		isStruct := tpField.Type.Kind() == reflect.Struct
-		isStructPtr := tpField.Type.Kind() == reflect.Ptr && tpField.Type.Elem().Kind() == reflect.Struct
-		isAnonymousPtr := tpField.Type.Kind() == reflect.Ptr && tpField.Anonymous
+		isStructPtr := tpField.Type.Kind() == reflect.Pointer && tpField.Type.Elem().Kind() == reflect.Struct
+		isAnonymousPtr := tpField.Type.Kind() == reflect.Pointer && tpField.Anonymous
 		if isAnonymousPtr {
 			field.Set(reflect.New(tpField.Type.Elem()))
 		}
@@ -381,7 +381,7 @@ func (s *Section) mapToSlice(secName string, val reflect.Value, isStrict bool) (
 func (s *Section) mapTo(v interface{}, isStrict bool) error {
 	typ := reflect.TypeOf(v)
 	val := reflect.ValueOf(v)
-	if typ.Kind() == reflect.Ptr {
+	if typ.Kind() == reflect.Pointer {
 		typ = typ.Elem()
 		val = val.Elem()
 	} else {
@@ -500,13 +500,13 @@ func reflectSliceWithProperType(key *Key, field reflect.Value, delim string, all
 		case reflect.String:
 			buf.WriteString(slice.Index(i).String())
 		case reflect.Int, reflect.Int64:
-			buf.WriteString(fmt.Sprint(slice.Index(i).Int()))
+			fmt.Fprint(&buf, slice.Index(i).Int())
 		case reflect.Uint, reflect.Uint64:
-			buf.WriteString(fmt.Sprint(slice.Index(i).Uint()))
+			fmt.Fprint(&buf, slice.Index(i).Uint())
 		case reflect.Float64:
-			buf.WriteString(fmt.Sprint(slice.Index(i).Float()))
+			fmt.Fprint(&buf, slice.Index(i).Float())
 		case reflect.Bool:
-			buf.WriteString(fmt.Sprint(slice.Index(i).Bool()))
+			fmt.Fprint(&buf, slice.Index(i).Bool())
 		case reflectTime:
 			buf.WriteString(slice.Index(i).Interface().(time.Time).Format(time.RFC3339))
 		default:
@@ -535,7 +535,7 @@ func reflectWithProperType(t reflect.Type, key *Key, field reflect.Value, delim
 		key.SetValue(fmt.Sprint(field.Interface().(time.Time).Format(time.RFC3339)))
 	case reflect.Slice:
 		return reflectSliceWithProperType(key, field, delim, allowShadow)
-	case reflect.Ptr:
+	case reflect.Pointer:
 		if !field.IsNil() {
 			return reflectWithProperType(t.Elem(), key, field.Elem(), delim, allowShadow)
 		}
@@ -559,7 +559,7 @@ func isEmptyValue(v reflect.Value) bool {
 		return v.Uint() == 0
 	case reflect.Float32, reflect.Float64:
 		return v.Float() == 0
-	case reflect.Interface, reflect.Ptr:
+	case reflect.Interface, reflect.Pointer:
 		return v.IsNil()
 	case reflectTime:
 		t, ok := v.Interface().(time.Time)
@@ -574,7 +574,7 @@ type StructReflector interface {
 }
 
 func (s *Section) reflectFrom(val reflect.Value) error {
-	if val.Kind() == reflect.Ptr {
+	if val.Kind() == reflect.Pointer {
 		val = val.Elem()
 	}
 	typ := val.Type()
@@ -606,14 +606,14 @@ func (s *Section) reflectFrom(val reflect.Value) error {
 			continue
 		}
 
-		if extends && tpField.Anonymous && (tpField.Type.Kind() == reflect.Ptr || tpField.Type.Kind() == reflect.Struct) {
+		if extends && tpField.Anonymous && (tpField.Type.Kind() == reflect.Pointer || tpField.Type.Kind() == reflect.Struct) {
 			if err := s.reflectFrom(field); err != nil {
 				return fmt.Errorf("reflect from field %q: %v", fieldName, err)
 			}
 			continue
 		}
 
-		if (tpField.Type.Kind() == reflect.Ptr && tpField.Type.Elem().Kind() == reflect.Struct) ||
+		if (tpField.Type.Kind() == reflect.Pointer && tpField.Type.Elem().Kind() == reflect.Struct) ||
 			(tpField.Type.Kind() == reflect.Struct && tpField.Type.Name() != "Time") {
 			// Note: The only error here is section doesn't exist.
 			sec, err := s.f.GetSection(fieldName)
@@ -641,7 +641,7 @@ func (s *Section) reflectFrom(val reflect.Value) error {
 			sliceOf := field.Type().Elem().Kind()
 
 			for i := 0; i < field.Len(); i++ {
-				if sliceOf != reflect.Struct && sliceOf != reflect.Ptr {
+				if sliceOf != reflect.Struct && sliceOf != reflect.Pointer {
 					return fmt.Errorf("field %q is not a slice of pointer or struct", fieldName)
 				}
 
@@ -688,11 +688,11 @@ func (s *Section) ReflectFrom(v interface{}) error {
 	val := reflect.ValueOf(v)
 
 	if s.name != DefaultSection && s.f.options.AllowNonUniqueSections &&
-		(typ.Kind() == reflect.Slice || typ.Kind() == reflect.Ptr) {
+		(typ.Kind() == reflect.Slice || typ.Kind() == reflect.Pointer) {
 		// Clear sections to make sure none exists before adding the new ones
 		s.f.DeleteSection(s.name)
 
-		if typ.Kind() == reflect.Ptr {
+		if typ.Kind() == reflect.Pointer {
 			sec, err := s.f.NewSection(s.name)
 			if err != nil {
 				return err
@@ -702,7 +702,7 @@ func (s *Section) ReflectFrom(v interface{}) error {
 
 		slice := val.Slice(0, val.Len())
 		sliceOf := val.Type().Elem().Kind()
-		if sliceOf != reflect.Ptr {
+		if sliceOf != reflect.Pointer {
 			return fmt.Errorf("not a slice of pointers")
 		}
 
@@ -721,7 +721,7 @@ func (s *Section) ReflectFrom(v interface{}) error {
 		return nil
 	}
 
-	if typ.Kind() == reflect.Ptr {
+	if typ.Kind() == reflect.Pointer {
 		val = val.Elem()
 	} else {
 		return errors.New("not a pointer to a struct")