complex-numbers: move exercise involving multiplication

[KevinWMatthews]

Should we move the test for the imaginary unit to the "multiply" group of unit tests?
I think it's currently too soon in the test suite.

There is a nice progression to the unit tests:

• real part
• imaginary part
• add
• subtract
• multiply

and so on. The test for the "imaginary unit" involves multiplication but is inserted between the "imaginary" and "add" groups.

I think this is purely historical. PR #718 created the tests, #1140 reordered them but missed this one.

I don't mind opening a PR but first I'd like to learn how to test changes.

[SaschaMann]

In #718 I put it as the first test case because, at least informally, complex numbers are often defined or thought of as a + bi where i² = -1. The other properties can all be derived from that.

Edit: This is also the definition the exercise description uses.

I don't really care about the position in the canonical-data but that was the intention behind it.

[KevinWMatthews]

@SaschaMann Ah, interesting! I didn't consider that point of view. I was trying to think of what the students would need to do to make the tests pass.

Maybe some mentors have feedback to give?

[ErikSchierboom]

No comment has been made on this PR in the last 3 years. @KevinWMatthews are you still interested in pursuing this issue?