fix(@angular/build): deduplicate spurious chokidar polling change events - #34188
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This pull request introduces a fileStats map to track the modification times and sizes of watched files, helping to prevent redundant change events when no actual modifications have occurred. The review feedback highlights a performance concern where synchronous file system operations (fs.statSync) are used inside the asynchronous next() method, which could block the Node.js event loop when processing many files. It is recommended to use asynchronous operations with Promise.all instead.
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When using Chokidar in polling mode, non-atomic file writes (such as open with O_TRUNC followed by write) can span across poll intervals and cause Chokidar to emit two 'change' events for a single file modification. If the initial rebuild completes quickly (e.g. in JIT mode), the trailing poll event can flush a second rebuild batch with the same file state. Track the last known mtimeMs and size of watched files in createChokidarWatcher and ignore 'modified' events when the file's mtimeMs and size have not changed since the previous queued or flushed event.
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…nts (#34188) When using Chokidar in polling mode, non-atomic file writes (such as open with O_TRUNC followed by write) can span across poll intervals and cause Chokidar to emit two 'change' events for a single file modification. If the initial rebuild completes quickly (e.g. in JIT mode), the trailing poll event can flush a second rebuild batch with the same file state. Track the last known mtimeMs and size of watched files in createChokidarWatcher and ignore 'modified' events when the file's mtimeMs and size have not changed since the previous queued or flushed event. PR Close #34188
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When using Chokidar in polling mode, non-atomic file writes (such as open with O_TRUNC followed by write) can span across poll intervals and cause Chokidar to emit two 'change' events for a single file modification. If the initial rebuild completes quickly (e.g. in JIT mode), the trailing poll event can flush a second rebuild batch with the same file state.
Track the last known mtimeMs and size of watched files in createChokidarWatcher and ignore 'modified' events when the file's mtimeMs and size have not changed since the previous queued or flushed event.