New test suite has problem with null

[svgeesus]

In the new color conversions tests:

white | 100, 0, null | 100, 0.0146,

notice the missing third parameter in the expected result.

The actual js lists the third parameter:

tests: [
	{
		args: "slategray",
		expect: [52.697472, 11.242899, 253.010088]
	},
	{
		args: "white",
		expect: [100, 0.0146, null]
	},
	{
		args: "black",
		expect: [0, 0, null]
	}
]

I suspect that this work-around might be the culprit:

check: check.deep(function (actual, expect) {
	if (expect === null || Number.isNaN(expect)) {
		// Treat NaN and null as equivalent for now
		return actual === null || Number.isNaN(actual);
	}

weirdly the third sub-test still passes.

Note to self: (unrelated to this bug) the white test should be corrected, we now calculate a chroma of 0 rather than the slightly-off chroma of 0.0146 due to #354 which also means we can improve the rather slack epsilon in this test)

[svgeesus]

Seems to be restricted to the html output, running the same test in node gives passes.

├── sRGB to LCH ✅ 3/3 PASS (1.4 ms)

[svgeesus]

Note to self: (unrelated to this bug) the white test should be corrected

Test failure now corrected with better expected values; unexpected removal of null in HTML output remains, however.

[svgeesus]

Fixed with 2428ea2 - use NaN in the actual expected results, it formats as null