Fix With() when logger has a group.

CHANGELOG.md

@@ -10,6 +10,12 @@ The format is based on [Keep a Changelog], and this project adheres to
 [Keep a Changelog]: https://keepachangelog.com/en/1.0.0/
 [Semantic Versioning]: https://semver.org/spec/v2.0.0.html
 
+## [Unreleased]
+
+### Fixed
+
+- `With()` now places attributes in the current group instead of at the root.
+
 ## [0.2.0] - 2024-07-19
 
 ### Added

spruce.go

@@ -22,15 +22,21 @@ func (h *handler) Enabled(context.Context, slog.Level) bool {
 
 func (h *handler) Handle(_ context.Context, rec slog.Record) error {
 	buf := &strings.Builder{}
-	attrs := slices.Clone(h.attrs)
+	var attrs []slog.Attr
 
 	if len(h.groups) == 0 {
+		attrs = slices.Clone(h.attrs)
 		rec.Attrs(func(attr slog.Attr) bool {
 			attrs = append(attrs, attr)
 			return true
 		})
 	} else {
 		var grouped []any
+
+		for _, attr := range h.attrs {
+			grouped = append(grouped, attr)
+		}
+
 		rec.Attrs(func(attr slog.Attr) bool {
 			grouped = append(grouped, attr)
 			return true

spruce_test.go

@@ -132,6 +132,21 @@ func TestHandler_WithAttrs_sameKey(t *testing.T) {
 	)
 }
 
+func TestHandler_WithAttrs_inGroupKey(t *testing.T) {
+	s := &testingTStub{T: t}
+	l := spruce.
+		NewTestLogger(s).
+		WithGroup("<group>").
+		With("<key>", "<value>")
+
+	l.Info("<message>")
+	s.Expect(
+		`[INFO <timestamp>] <message>`,
+		`╰─┬ <group>`,
+		`  ╰── <key> ┈ <value>`,
+	)
+}
+
 func TestHandler_WithGroup(t *testing.T) {
 	s := &testingTStub{T: t}
 	l := spruce.