UI5 / cli / 34128268162

94%

Build Type

push

github

Committed by matz3

Commit Message

fix(project): Memoize in-flight native watcher load to avoid polling race

Concurrent subscribe() calls (as issued by WatchHandler via Promise.all)
raced on the native-backend memoization: nativeBackendLoaded was flipped
to true before the dynamic import() resolved, so callers settling before
the winner assigned nativeBackend read a null value and silently fell back
to the polling backend. On projects with many watched paths (e.g. the
OpenUI5 testsuite), that meant nearly all source watchers polled ~42k
files every 250ms, pegging idle CPU at ~250%.

Memoize the in-flight promise instead of a pre-await boolean so concurrent
callers await the same import and all observe the resolved backend. Add a
regression test that fires concurrent subscribe() calls before the first
load resolves and asserts all use the native backend.

Coverage Stats

7305 of 8052 branches covered (90.72%)

Branch coverage included in aggregate %.

4 of 6 new or added lines in 1 file covered. (66.67%)

1 existing line in 1 file now uncovered.

13984 of 14585 relevant lines covered (95.88%)

5252.45 hits per line