fix: encode mixed arrays with inline table elements

Assisted-by: GLM 5.3 Flash

encode_test.go

@@ -504,6 +504,79 @@ func TestMarshalNestedArrays(t *testing.T) {
 	}
 }
 
+func TestMarshalMixedArrayWithInlineTable(t *testing.T) {
+	// Parse accepts a mixed array (TOML allows any value kinds in one array),
+	// so Marshal of the parsed tree must re-emit it. The table element has no
+	// header form inside a value array and renders inline.
+	tree, err := Parse([]byte("arr = [1, {a = 2}, \"x\"]\n"))
+	if err != nil {
+		t.Fatalf("parse: %v", err)
+	}
+	out, err := Marshal(tree)
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	want := "arr = [1, {a = 2}, \"x\"]\n"
+	if string(out) != want {
+		t.Fatalf("output mismatch:\ngot:  %q\nwant: %q", out, want)
+	}
+	re, err := Parse(out)
+	if err != nil {
+		t.Fatalf("re-parse: %v", err)
+	}
+	if !reflect.DeepEqual(tree, re) {
+		t.Fatalf("round-trip changed the tree:\nwas: %#v\nnow: %#v", tree, re)
+	}
+}
+
+func TestMarshalNestedInlineTables(t *testing.T) {
+	tree := map[string]any{
+		"mix": []any{
+			int64(1),
+			map[string]any{"deep": map[string]any{"n": int64(0)}, "list": []any{"a", true}},
+			map[string]any{},
+		},
+	}
+	out, err := Marshal(tree)
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	want := "mix = [1, {deep = {n = 0}, list = [\"a\", true]}, {}]\n"
+	if string(out) != want {
+		t.Fatalf("output mismatch:\ngot:  %q\nwant: %q", out, want)
+	}
+}
+
+func TestMarshalInlineTableWithDatetime(t *testing.T) {
+	when := time.Date(1979, 5, 27, 7, 32, 0, 0, time.UTC)
+	tree := map[string]any{
+		"mix": []any{when, map[string]any{"t": LocalDateTime{when}}},
+	}
+	out, err := Marshal(tree)
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	want := "mix = [1979-05-27T07:32:00Z, {t = 1979-05-27T07:32:00}]\n"
+	if string(out) != want {
+		t.Fatalf("output mismatch:\ngot:  %q\nwant: %q", out, want)
+	}
+}
+
+func TestMarshalArrayOfTablesStaysHeaderForm(t *testing.T) {
+	tree, err := Parse([]byte("[[items]]\nname = \"a\"\n\n[[items]]\nname = \"b\"\n"))
+	if err != nil {
+		t.Fatalf("parse: %v", err)
+	}
+	out, err := Marshal(tree)
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	want := "[[items]]\nname = \"a\"\n\n[[items]]\nname = \"b\"\n"
+	if string(out) != want {
+		t.Fatalf("output mismatch:\ngot:  %q\nwant: %q", out, want)
+	}
+}
+
 func TestMarshalFloatExponentNoLeadingZero(t *testing.T) {
 	// strconv.FormatFloat with 'g' would produce "1e+06" (leading zero in
 	// exponent). The encoder must strip it so the output is "1e+6".