fn testDirnamePosix(input: []const u8, expected_output: ?[]const u8) !void
fn testDirnamePosix(input: []const u8, expected_output: ?[]const u8) !void { if (dirnamePosix(input)) |output| { try testing.expect(mem.eql(u8, output, expected_output.?)); } else { try testing.expect(expected_output == null); } }