Arbor store - Proxying improvements

packages/arbor-react/src/useArbor.ts

@@ -1,6 +1,7 @@
 import {
   Arbor,
   ArborNode,
+  isDetached,
   isNode,
   isProxiable,
   ScopedStore,
@@ -76,7 +77,9 @@ function useArborDeprecated<T extends object>(store: Store<T>): ArborNode<T> {
     }
 
     return store.subscribe(() => {
-      setState(store.state)
+      if (!isDetached(store.state)) {
+        setState(store.state)
+      }
     })
   }, [state, store])
 

packages/arbor-react/tests/useArbor.test.ts

@@ -67,14 +67,14 @@ describe("useArbor", () => {
 
     const { result, unmount } = renderHook(() => useArbor(store))
 
-    const initialSstate = result.current
+    const initialState = result.current
 
     act(() => {
       result.current.count++
     })
 
     const nextState = result.current
-    expect(initialSstate).not.toBe(nextState)
+    expect(initialState).not.toBe(nextState)
 
     unmount()
 

packages/arbor-store/src/utilities.ts

@@ -95,7 +95,15 @@ export function isDetached<T extends object>(node: T): boolean {
   // but an ancestor has been detached.'
   if (!isNode(node)) return true
 
-  return !node.$tree.getLinkFor(node) && !node.$tree.getNodeFor<Node>(node)
+  const path = node.$tree.getPathFor(node)
+
+  if (!path) {
+    return true
+  }
+
+  return path.seeds.some(
+    (seed) => !node.$tree.getLinkFor(seed) && !node.$tree.getNodeFor<Node>(seed)
+  )
 }
 
 /**

packages/arbor-store/tests/arbor.test.ts

@@ -352,9 +352,8 @@ describe("Arbor", () => {
 
       delete store.state.todos[0]
 
-      // todos[0] should still exist in the previous snapshot
-      expect(todos[0]).toBeDefined()
-      expect(unwrap(todos[0])).toBe(state.todos[0])
+      expect(todos).toEqual([{ text: "Walk the dogs" }])
+      expect(todos[0]).toEqual({ text: "Walk the dogs" })
 
       expect(store.state).toEqual({ todos: [{ text: "Walk the dogs" }] })
       expect(store.state.todos).toEqual([{ text: "Walk the dogs" }])
@@ -822,6 +821,31 @@ describe("Arbor", () => {
       expect(subscriber2).not.toHaveBeenCalled()
     })
 
+    it("does not trigger notifications when mutations are performed on nodes belonging to detached paths", () => {
+      const store = new Arbor({
+        todos: [
+          { id: 1, done: false, author: { name: "Alice", age: 29 } },
+          { id: 2, done: false, author: { name: "Bob", age: 30 } },
+        ],
+      })
+
+      const todo0 = store.state.todos[0]
+      const alice = store.state.todos[0].author
+      const subscriber1 = vi.fn()
+      const subscriber2 = vi.fn()
+
+      delete store.state.todos[0]
+
+      store.subscribe(subscriber1)
+      store.subscribeTo(alice, subscriber2)
+      store.subscribeTo(todo0, subscriber2)
+
+      expect(() => (todo0.done = true)).toThrow(DetachedNodeError)
+      expect(() => alice.age++).toThrow(DetachedNodeError)
+      expect(subscriber1).not.toHaveBeenCalled()
+      expect(subscriber2).not.toHaveBeenCalled()
+    })
+
     it("ignores assignments when new value is the current value", () => {
       const alice = { name: "Alice" }
       const store = new Arbor({

packages/arbor-store/tests/utilities/isDetached.test.ts

@@ -25,4 +25,18 @@ describe("isDetached", () => {
 
     expect(isDetached(node)).toBe(true)
   })
+
+  it("returns true if the node belongs to a detached path", () => {
+    const store = new Arbor({
+      todos: [
+        { id: 1, text: "Do the dishes", author: { name: "Alice" } },
+        { id: 2, text: "Walk the dogs", author: { name: "Bob" } },
+      ],
+    })
+
+    const alice = store.state.todos[0].author
+    delete store.state.todos[0]
+
+    expect(isDetached(alice)).toBe(true)
+  })
 })