diff --git a/slice_test.go b/slice_test.go
index 915a1da..861c006 100644
--- a/slice_test.go
+++ b/slice_test.go
@@ -19,3 +19,39 @@ func TestAppend(t *testing.T) {
 		t.Fatalf("len(*Slice) != 2")
 	}
 }
+
+// TestAppendLength tests Slice.AppendLength.
+func TestAppendLength(t *testing.T) {
+	s := &slice.Slice[int]{}
+	if n := s.AppendLength(1, 2, 3, 4); n != len(*s) {
+		t.Fatalf("len(*Slice) != 4")
+	}
+}
+
+// TestBounds tests Slice.Bounds.
+func TestBounds(t *testing.T) {
+	s := &slice.Slice[int]{}
+	if ok := s.Bounds(0); ok {
+		t.Fatalf("*Slice.Bounds() != false")
+	}
+	s.Append(1)
+	if ok := s.Bounds(0); !ok {
+		t.Fatalf("*Slice.Bounds() != true")
+	}
+}
+
+// TestConcatenate tests Slice.Concatenate.
+func TestConcatenate(t *testing.T) {
+	s := &slice.Slice[int]{}
+	s.Append(1)
+	s.Concatenate(&slice.Slice[int]{2, 3})
+	if ok := (*s)[0] == 1; !ok {
+		t.Fatalf("*Slice[0] != 1")
+	}
+	if ok := (*s)[1] == 2; !ok {
+		t.Fatalf("*Slice[1] != 2")
+	}
+	if ok := (*s)[2] == 3; !ok {
+		t.Fatalf("*Slice[2] != 3")
+	}
+}