Adding withAttr

errkit/README.md

@@ -47,10 +47,10 @@ with attributes support you can do following
 err := errkit.New("i/o timeout")
 
 // xyz.go
-err = errkit.WithAttr(err,slog.Any("resource",domain))
+err = errkit.WithAttr(err, slog.String("resource", domain))
 
 // abc.go
-err = errkit.WithAttr(err,slog.Any("action","download"))
+err = errkit.WithAttr(err, slog.String("action", "download"))
 ```
 
 ## Note

errkit/errors.go

@@ -293,7 +293,7 @@ func (e *ErrorX) ResetKind() *ErrorX {
 	return e
 }
 
-// Deprecated: use Attrs instead
+// Deprecated: use WithAttr instead
 //
 // SetAttr sets additional attributes to a given error
 // it only adds unique attributes and ignores duplicates
@@ -303,6 +303,9 @@ func (e *ErrorX) ResetKind() *ErrorX {
 //
 //	this is correct (√)
 //	myError.SetAttr(slog.String("address",host))
+//
+//	Recommended replacement:
+//	errkit.WithAttr(myError, slog.String("address", host))
 func (e *ErrorX) SetAttr(s ...slog.Attr) *ErrorX {
 	e.init()
 	for _, attr := range s {

errkit/errors_test.go

@@ -10,6 +10,7 @@ import (
 	"go.uber.org/multierr"
 
 	stderrors "errors"
+	"log/slog"
 )
 
 // what are these tests ?
@@ -126,3 +127,41 @@ func TestErrorString(t *testing.T) {
 		x.Error(),
 	)
 }
+
+func TestWithAttr(t *testing.T) {
+	// Test WithAttr function
+	originalErr := New("connection failed")
+
+	// Add attributes using WithAttr
+	err := WithAttr(originalErr, slog.String("resource", "database"), slog.Int("port", 5432))
+
+	// Verify the error can be unwrapped to ErrorX
+	var errx *ErrorX
+	require.True(t, errors.As(err, &errx), "expected to be able to unwrap to ErrorX")
+
+	// Check that attributes were added
+	attrs := errx.Attrs()
+	require.Len(t, attrs, 2, "expected 2 attributes")
+
+	// Verify specific attributes
+	foundResource := false
+	foundPort := false
+	for _, attr := range attrs {
+		if attr.Key == "resource" && attr.Value.String() == "database" {
+			foundResource = true
+		}
+		if attr.Key == "port" && attr.Value.Int64() == 5432 {
+			foundPort = true
+		}
+	}
+	require.True(t, foundResource, "expected to find resource attribute")
+	require.True(t, foundPort, "expected to find port attribute")
+
+	// Test that WithAttr works with nil error
+	nilErr := WithAttr(nil, slog.String("test", "value"))
+	require.Nil(t, nilErr, "expected nil error to return nil")
+
+	// Test that WithAttr works with empty attrs
+	emptyErr := WithAttr(originalErr)
+	require.Equal(t, originalErr, emptyErr, "expected original error when no attrs provided")
+}

errkit/helpers.go

@@ -210,6 +210,26 @@ func With(err error, args ...any) error {
 	return x
 }
 
+// WithAttr adds extra attributes to the error using slog.Attr
+//
+//	err = errkit.WithAttr(err, slog.String("resource", domain))
+//	err = errkit.WithAttr(err, slog.Int("port", 80), slog.String("protocol", "tcp"))
+func WithAttr(err error, attrs ...slog.Attr) error {
+	if err == nil {
+		return nil
+	}
+	if len(attrs) == 0 {
+		return err
+	}
+	x := &ErrorX{}
+	x.init()
+	parseError(x, err)
+	for _, attr := range attrs {
+		x.record.Add(attr)
+	}
+	return x
+}
+
 // GetAttr returns all attributes of given error if it has any
 func GetAttr(err error) []slog.Attr {
 	if err == nil {