With 'drop-newest', a shareSync() consumer that needed to pull while
the buffer was at the budget discarded one entry from the source and
then returned { done: true } even though the source was not exhausted.
for...of loops, and anything else that trusts the iterator protocol,
silently stopped consuming. There is no correct alternative in a
synchronous context: the slowest consumer cannot advance while another
consumer's next() is running, so the call can neither wait for budget
nor keep discarding until budget is released.
Reject 'drop-newest' in shareSync() with ERR_INVALID_ARG_VALUE, as is
already done for 'unbounded'. The two tests that asserted the previous
"done but not detached" behavior are replaced by one that checks the
rejection. Also document how 'unbounded' and 'drop-newest' make the
async share() wait for the slowest consumer.
Assisted-by: OpenCode
Signed-off-by: James M Snell <jasnell@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/66483
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
James M Snell
d4ec9ff27d