Stop on a condition in RxJS

RxJS interview exercise on Filtering, difficulty 2 of 3. Solve it in the editor beside a worked example; the tests run the moment you do.

Write untilNegative(source$): emit numbers until the first negative one, which is not emitted; then complete, even if the source continues. Also untilNegativeInclusive(source$), which does emit that first negative before completing.

Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Progress is saved in your browser, and in your account if you sign in.

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