FloatingDecimal parsing is covered by tests in class TestFloatingDecimal.
However, these tests only parse strings produced by [Float|Double].toString(), which are very structured and not generic enough. Further, they are limited to decimal input.

To better cover cases of input that is less structured and that better represent real-world scenarios, more random tests are recommended.
Most aspects of a syntactically correct input string should be randomized, including the number of digits, the presence of a point, whitespaces, etc.