1const std = @import("std");
 2
 3test "detect leak" {
 4    const gpa = std.testing.allocator;
 5    var list: std.ArrayList(u21) = .empty;
 6    // missing `defer list.deinit(gpa);`
 7    try list.append(gpa, '☔');
 8
 9    try std.testing.expect(list.items.len == 1);
10}
11
12// test_error=1 tests leaked memory