the C++ tests have trailing newlines

technically that is correct. there's nothing saying there won't be or that rows will be the same width.

however. it is poorly communicated (as in, misleading) and it is different from other languges and is thus indeed an issue.

....
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...X
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Expected: equal to "[3, 7]"
Actual: "[3, 6]"

If 0,0 is bottom left corner then this test case is wrong..

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