Improve error annotations in read.go, rename interface{} to any (#333)

Author: suyashkumar

dataset.go

@@ -33,7 +33,7 @@ func (d *Dataset) FindElementByTag(tag tag.Tag) (*Element, error) {
 			return e, nil
 		}
 	}
-	return nil, ErrorElementNotFound
+	return nil, fmt.Errorf("unable to find %v element: %w", tag, ErrorElementNotFound)
 }
 
 func (d *Dataset) transferSyntax() (binary.ByteOrder, bool, error) {
@@ -57,7 +57,7 @@ func (d *Dataset) FindElementByTagNested(tag tag.Tag) (*Element, error) {
 			return e, nil
 		}
 	}
-	return nil, ErrorElementNotFound
+	return nil, fmt.Errorf("unable to find %v element: %w", tag, ErrorElementNotFound)
 }
 
 // FlatIterator will be deprecated soon in favor of

element.go

@@ -91,7 +91,7 @@ type Value interface {
 	ValueType() ValueType
 	// GetValue returns the underlying value that this Value holds. What type is returned here can be determined exactly
 	// from the ValueType() of this Value (see the ValueType godoc).
-	GetValue() interface{} // TODO: rename to Get to read cleaner
+	GetValue() any // TODO: rename to Get to read cleaner
 	String() string
 	MarshalJSON() ([]byte, error)
 	// Equals returns true if this value equals the input Value.
@@ -107,7 +107,7 @@ type Value interface {
 // Acceptable types: []int, []string, []byte, []float64, PixelDataInfo,
 // [][]*Element (represents a sequence, which contains several
 // items which each contain several elements).
-func NewValue(data interface{}) (Value, error) {
+func NewValue(data any) (Value, error) {
 	switch data.(type) {
 	case []int:
 		return &intsValue{value: data.([]int)}, nil
@@ -127,11 +127,11 @@ func NewValue(data interface{}) (Value, error) {
 		}
 		return &sequencesValue{value: sequenceItems}, nil
 	default:
-		return nil, ErrorUnexpectedDataType
+		return nil, fmt.Errorf("NewValue: unexpected data type %T: %w", data, ErrorUnexpectedDataType)
 	}
 }
 
-func mustNewValue(data interface{}) Value {
+func mustNewValue(data any) Value {
 	v, err := NewValue(data)
 	if err != nil {
 		panic(err)
@@ -142,7 +142,7 @@ func mustNewValue(data interface{}) Value {
 // NewElement creates a new DICOM Element with the supplied tag and with a value
 // built from the provided data. The data can be one of the types that is
 // acceptable to NewValue.
-func NewElement(t tag.Tag, data interface{}) (*Element, error) {
+func NewElement(t tag.Tag, data any) (*Element, error) {
 	tagInfo, err := tag.Find(t)
 	if err != nil {
 		return nil, err
@@ -164,15 +164,15 @@ func NewElement(t tag.Tag, data interface{}) (*Element, error) {
 	}, nil
 }
 
-func mustNewElement(t tag.Tag, data interface{}) *Element {
+func mustNewElement(t tag.Tag, data any) *Element {
 	elem, err := NewElement(t, data)
 	if err != nil {
 		log.Panic(err)
 	}
 	return elem
 }
 
-func mustNewPrivateElement(t tag.Tag, rawVR string, data interface{}) *Element {
+func mustNewPrivateElement(t tag.Tag, rawVR string, data any) *Element {
 	value, err := NewValue(data)
 	if err != nil {
 		log.Panic(fmt.Errorf("error creating value: %w", err))
@@ -217,9 +217,9 @@ type bytesValue struct {
 	value []byte
 }
 
-func (b *bytesValue) isElementValue()       {}
-func (b *bytesValue) ValueType() ValueType  { return Bytes }
-func (b *bytesValue) GetValue() interface{} { return b.value }
+func (b *bytesValue) isElementValue()      {}
+func (b *bytesValue) ValueType() ValueType { return Bytes }
+func (b *bytesValue) GetValue() any        { return b.value }
 func (b *bytesValue) String() string {
 	return fmt.Sprintf("%v", b.value)
 }
@@ -242,9 +242,9 @@ type stringsValue struct {
 	value []string
 }
 
-func (s *stringsValue) isElementValue()       {}
-func (s *stringsValue) ValueType() ValueType  { return Strings }
-func (s *stringsValue) GetValue() interface{} { return s.value }
+func (s *stringsValue) isElementValue()      {}
+func (s *stringsValue) ValueType() ValueType { return Strings }
+func (s *stringsValue) GetValue() any        { return s.value }
 func (s *stringsValue) String() string {
 	return fmt.Sprintf("%v", s.value)
 }
@@ -273,9 +273,9 @@ type intsValue struct {
 	value []int
 }
 
-func (i *intsValue) isElementValue()       {}
-func (i *intsValue) ValueType() ValueType  { return Ints }
-func (i *intsValue) GetValue() interface{} { return i.value }
+func (i *intsValue) isElementValue()      {}
+func (i *intsValue) ValueType() ValueType { return Ints }
+func (i *intsValue) GetValue() any        { return i.value }
 func (i *intsValue) String() string {
 	return fmt.Sprintf("%v", i.value)
 }
@@ -304,9 +304,9 @@ type floatsValue struct {
 	value []float64
 }
 
-func (f *floatsValue) isElementValue()       {}
-func (f *floatsValue) ValueType() ValueType  { return Floats }
-func (f *floatsValue) GetValue() interface{} { return f.value }
+func (f *floatsValue) isElementValue()      {}
+func (f *floatsValue) ValueType() ValueType { return Floats }
+func (f *floatsValue) GetValue() any        { return f.value }
 func (f *floatsValue) String() string {
 	return fmt.Sprintf("%v", f.value)
 }
@@ -345,7 +345,7 @@ func (s *SequenceItemValue) ValueType() ValueType { return SequenceItem }
 // GetValue returns the underlying value that this Value holds. What type is
 // returned here can be determined exactly from the ValueType() of this Value
 // (see the ValueType godoc).
-func (s *SequenceItemValue) GetValue() interface{} { return s.elements }
+func (s *SequenceItemValue) GetValue() any { return s.elements }
 
 // String is used to get a string representation of this struct.
 func (s *SequenceItemValue) String() string {
@@ -379,9 +379,9 @@ type sequencesValue struct {
 	value []*SequenceItemValue
 }
 
-func (s *sequencesValue) isElementValue()       {}
-func (s *sequencesValue) ValueType() ValueType  { return Sequences }
-func (s *sequencesValue) GetValue() interface{} { return s.value }
+func (s *sequencesValue) isElementValue()      {}
+func (s *sequencesValue) ValueType() ValueType { return Sequences }
+func (s *sequencesValue) GetValue() any        { return s.value }
 func (s *sequencesValue) String() string {
 	// TODO: consider adding more sophisticated formatting
 	return fmt.Sprintf("%+v", s.value)
@@ -440,9 +440,9 @@ type pixelDataValue struct {
 	PixelDataInfo
 }
 
-func (p *pixelDataValue) isElementValue()       {}
-func (p *pixelDataValue) ValueType() ValueType  { return PixelData }
-func (p *pixelDataValue) GetValue() interface{} { return p.PixelDataInfo }
+func (p *pixelDataValue) isElementValue()      {}
+func (p *pixelDataValue) ValueType() ValueType { return PixelData }
+func (p *pixelDataValue) GetValue() any        { return p.PixelDataInfo }
 func (p *pixelDataValue) String() string {
 	if len(p.Frames) == 0 {
 		return "empty pixel data"
@@ -530,7 +530,7 @@ func MustGetPixelDataInfo(v Value) PixelDataInfo {
 
 // allValues is used for tests that need to pass in instances of the unexported
 // value structs to cmp.AllowUnexported.
-var allValues = []interface{}{
+var allValues = []any{
 	floatsValue{},
 	intsValue{},
 	stringsValue{},

element_test.go

@@ -2,6 +2,7 @@ package dicom
 
 import (
 	"encoding/json"
+	"errors"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -62,7 +63,7 @@ func TestElement_String(t *testing.T) {
 func TestNewValue(t *testing.T) {
 	cases := []struct {
 		name      string
-		data      interface{}
+		data      any
 		wantValue Value
 		wantError error
 	}{
@@ -141,7 +142,7 @@ func TestNewValue(t *testing.T) {
 func TestNewValue_UnexpectedType(t *testing.T) {
 	data := 10
 	_, err := NewValue(data)
-	if err != ErrorUnexpectedDataType {
+	if !errors.Is(err, ErrorUnexpectedDataType) {
 		t.Errorf("NewValue(%v) expected an error. got: %v, want: %v", data, err, ErrorUnexpectedDataType)
 	}
 }

pkg/debug/debug.go

@@ -1,3 +1,4 @@
+//go:build debug
 // +build debug
 
 package debug
@@ -10,6 +11,6 @@ func Log(data string) {
 }
 
 // Logf only logs with a formatted string when the debug build flag is present.
-func Logf(format string, args ...interface{}) {
+func Logf(format string, args ...any) {
 	log.Printf(format, args...)
 }

pkg/debug/default.go

@@ -1,3 +1,4 @@
+//go:build !debug
 // +build !debug
 
 package debug
@@ -6,4 +7,4 @@ package debug
 func Log(data string) {}
 
 // Logf only logs with a formatted string when the debug build flag is present.
-func Logf(format string, args ...interface{}) {}
+func Logf(format string, args ...any) {}

pkg/personname/groupInfo_test.go

@@ -396,7 +396,7 @@ func TestGroupInfo_DCM_panic(t *testing.T) {
 		TrailingNullLevel: 5,
 	}
 
-	var recovered interface{}
+	var recovered any
 
 	func() {
 		defer func() {

pkg/personname/info_test.go

@@ -493,7 +493,7 @@ func TestInfo_DCM_panic(t *testing.T) {
 		TrailingNullLevel: 3,
 	}
 
-	var recovered interface{}
+	var recovered any
 
 	func() {
 		defer func() {