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status: accepted

Removal of experimental watchers on Pulsar

Removal of @atom/watcher and others

Atom had four different ways of watching for filesystem changes. Two used an in-house library called @atom/watcher - one for "polling" and other for "experimental". It also had a different library to watch files for changes that basically used the Tree-View package's watch mechanism

Decision Drivers

• We don't know what "experimental watcher" means, and we have no way of knowing
• We don't want to support another "in-house" library to watch files, specially considering that it's a binary library
• We know that tree-view can use Pulsar's watcher mechanism to watch files, meaning we enter somekind of weird loop

Considered Options

• Use nsfw only
• Use chokidar only

Decision Outcome

Use only nsfw library to watch for changes, and use the community version of that library. Make the config for "watch" in Pulsar reflect that we only have nsfw as an option (Native operating system APIs).

Validation

Files are still being watched. Config failed to watch, but that's because of a different issue - see ADR 001

More Information

We still have another "watch" library called Pathwatcher. It is used by TextBuffer, atom-keymap and tree-view. It may be possible to remove this library to use only Pulsar's watch mechanism (it is available under the public API) so every code will basically use the public API and they will all respect the choice of what Pulsar defined, if we decide to introduce new file watcher libraries in the future