Kikobeats / isolated-function / 36833840140

97%

push

github

feat: take a named span out of run so the phases add up (#86)

* feat: take a named span out of run so the phases add up

`install`, `build`, `spawn` and `run` are siblings that account for
`total`. Spans reported alongside them broke that: they sit inside the
program's execution, so the row no longer added up and a named span read
as a peer of `run` while actually being part of it.

`run` now reports the time nothing claimed. A span recorded with
`__isolated_time` wrapped real elapsed time, so it is taken out; only the
outermost counts, and nesting one inside another does not subtract it
twice. `__isolated_phase` records a number the program asserts rather
than time it measured, so it leaves `run` alone.

`spawn` still uses the whole execution. It is what the host saw minus
what the child did, so a shorter `run` would otherwise be absorbed there
and the phase would grow for no reason. There is a test comparing it
against a run that names nothing.

The sum is bounded rather than exact: time the host spends waiting, such
as on a build another call is performing, belongs to no phase. The test
asserts the parts never exceed the total rather than matching it, after
the stricter version passed alone and failed under the parallel suite.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* fix: account for the window spans were open, not the first one to start

A shared depth counter treated overlapping siblings as nested, so only
the span that started first was subtracted. Reproduced with two spans
under one `Promise.all`:

  a = 50   b = 201   run = 150

150ms that `b` had already measured stayed in `run`, and which span was
subtracted depended on start order.

What is subtracted is now the union of the intervals a span was open:
the clock starts when the first span opens and the elapsed window is
taken when the last one closes. Overlapping siblings count once between
them, and a nested span is still not counted twice.

  a = 51   b = 201... (continued)

305 of 327 branches covered (93.27%)

Branch coverage included in aggregate %.

23 of 23 new or added lines in 2 files covered. (100.0%)

1266 of 1295 relevant lines covered (97.76%)

54.64 hits per line