mobxjs/mobx mobx@7.0.1

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Patch Changes

• 9444c624b957b489875e1c6b45deb290034ce4e9 #4694 Thanks @mrpmohiburrahman! - fix: onBecomeObserved is now called for the dependencies of a computed that becomes observed while serving a cached value. Previously, observation only cascaded when the newly observed computed also happened to recompute, so an observable with a live observer chain up to a running reaction could still report itself as unobserved and never fire its hook.

• 53bb83fdf455a4e606bb721ea10040ded7c57796 #4683 Thanks @gesposito! - perf: fast-path primitives in deepEnhancer. Writing a primitive into a deep observable no longer runs the observable/array/plain-object/Map/Set/function type checks; primitives can never be made observable, so they are returned immediately. Creating an observable array of primitives is ~4x faster, and observable Set/Map writes are ~20-25% faster in the perf suite.

• 030498d6b2bfe4cc27340fed8c706177cb3b28e1 #4684 Thanks @a-y-ibrahim! - Fix a stack overflow ("Maximum call stack size exceeded") that could occur when an onBecomeUnobserved handler disposes a Reaction. Disposing a Reaction re-enters endBatch(), which used to recurse into the same pendingUnobservations drain loop instead of letting the already-running outer loop pick up the newly queued items, causing unbounded stack depth for long enough chains.

• a9086076b9ead1a9c933215bffaa9b57d44f6829 #4681 Thanks @spokodev! - Fix ObservableSet union, intersection and symmetricDifference to return results in receiver order, matching native Set, when the argument is a plain Set.

• c65a4e14cf48b42cb792dc4c64edbcf56234b32d #4682 Thanks @gesposito! - perf: lazily allocate the internal observers_ Set. Atoms and computed values no longer allocate an empty Set upfront; it is created on first observer instead. Most atoms in large stores are never observed, so this saves roughly 160 bytes per unobserved atom (e.g. ~35% lower heap usage when hydrating 50k instances with 10 observable fields each).