diff --git a/edit.jai b/edit.jai
index 9c8eda4..ad7d533 100644
--- a/edit.jai
+++ b/edit.jai
@@ -245,7 +245,7 @@ handle_arrow :: (state: *State, key_code: Input.Key_Code) {
 
 handle_arrow :: (using state: *State, using event: Input.Event) {
     visible_lines := get_visible_lines(state);
-
+    if visible_lines.count == 0 return;
 
     if key_code == {
         case .ARROW_UP;    
@@ -259,7 +259,8 @@ handle_arrow :: (using state: *State, using event: Input.Event) {
         case .ARROW_DOWN;
             if cursor_y == visible_lines.count - 1 {
                 first_line = min(first_line + 1, lines.count);
-            } else {
+	    } else if cursor_y + first_line + visible_lines.count >= lines.count {
+	    } else {
                 cursor_y += 1;
             }
 
@@ -287,6 +288,7 @@ handle_arrow :: (using state: *State, using event: Input.Event) {
 }
 
 get_visible_lines :: (using state: State) -> [][..]u8 {
+    if line_height <= 1 || window_height == 0 return .[];
     num_lines_in_screen := window_height / line_height - 1;
     return array_view(lines, first_line, num_lines_in_screen);
 }
diff --git a/test.jai b/test.jai
index e6a1165..6c2a0d5 100644
--- a/test.jai
+++ b/test.jai
@@ -1,5 +1,73 @@
 main :: () {
+    print("\nBeginning tests...\n");
+    // test_handle_arrow_empty_lines();
+    // test_handle_arrow_one_line();
+    x := 1;
+    y := 2;
+    assert_test(x == y);
 }
 
-#load "edit.jai";
+test_handle_arrow_empty_lines :: () {
+    state: State;
+    state.cursor_y = 0;
+    state.cursor_x = 0;
+
+    codes := Input.Key_Code.[.ARROW_DOWN, .ARROW_UP, .ARROW_LEFT, .ARROW_RIGHT];
+    for codes {
+	handle_arrow(*state, .{key_code=it});
+	assert(state.cursor_x == 0 && state.cursor_y == 0, "%: cursor_x % & cursor_y %", it, state.cursor_x, state.cursor_y);
+    }
+
+    print("test_handle_arrow_empty_lines completed successfully\n");
+}
+
+test_handle_arrow_one_line :: () {
+    state: State;
+    state.cursor_y = 0;
+    state.cursor_x = 0;
+    
+    line: [..]u8;
+    line_str := "foo bar";
+    
+    array_add(*line, .{data=line_str.data, count=line_str.count});
+    array_add(*state.lines, line);
+
+    codes := Input.Key_Code.[.ARROW_DOWN, .ARROW_UP, .ARROW_LEFT];
+    for codes {
+	handle_arrow(*state, .{key_code=it});
+	assert(state.cursor_x == 0 && state.cursor_y == 0);
+    }
+
+    handle_arrow(*state, .{key_code=.ARROW_RIGHT});
+    assert(state.cursor_x == 1 && state.cursor_y == 0);    
+
+    print("test_handle_arrow_one_line completed successfully\n");
+}
+
+assert_test :: (value: bool, $code := #caller_code) {
+    builder: String_Builder;
+    root, expressions := compiler_get_nodes(code);
+    loc := #location(code);
+
+    print_to_builder(*builder, "%:%: Test: ", loc.fully_pathed_filename, loc.line_number);
+    print_expression(*builder, root);
+    append(*builder, "\n");
+    `result := #insert code;
+    if !result {
+	for expressions {
+	    if it == root continue;
+	    print_expression(*builder, it);
+	    append(*builder, "\n");
+	}
+	append(*builder, "\n");
+	`expression := builder_to_string(*builder);
+	`print("%\n", expression);
+    } else {
+	`print("Passed!\n");
+    }
+}
+
+#import,file "edit.jai";
 #import "Basic";
+#import "Compiler";
+#import "Program_Print";