This approach is neat for observability, but it's worth noticing that it essentially quantises all of your samples down to the vertical resolution of your graph. If you somehow introduced a bug that caused an error that was smaller than the step size then these tests wouldn't catch it.
(e.g. if you somehow managed to introduce a constant DC-offset of +0.05, with the shown step size of 0.2, these tests would probably never pick it up, modulo rounding.)
That said, these tests are great for asserting that specific functionality does broadly what it says on the tin, and making it easy to understand why not if they fail. We'll likely start using this technique at Fourier Audio (shameless plug) as a more observable functionality smoke test to augment finer-grained analytic tests that assert properties of the output waveform samples directly.
(e.g. if you somehow managed to introduce a constant DC-offset of +0.05, with the shown step size of 0.2, these tests would probably never pick it up, modulo rounding.)
That said, these tests are great for asserting that specific functionality does broadly what it says on the tin, and making it easy to understand why not if they fail. We'll likely start using this technique at Fourier Audio (shameless plug) as a more observable functionality smoke test to augment finer-grained analytic tests that assert properties of the output waveform samples directly.