fix(proxy-state-tree): run object changes first to update state before running mutation changes

Author: christianalfoni

packages/node_modules/proxy-state-tree/src/index.test.ts

@@ -392,6 +392,27 @@ describe('REACTIONS', () => {
     tree.flush()
     expect(reactionCount).toBe(1)
   })
+  test('should be able to manually add a path to the current tracking', () => {
+    let renderCount = 0
+    const tree = new ProxyStateTree({
+      foo: 'bar',
+    })
+    const state = tree.get()
+    function render() {
+      const trackId = tree.startPathsTracking()
+      tree.addTrackingPath('foo')
+      renderCount++
+      return tree.clearPathsTracking(trackId)
+    }
+    const listener = tree.addMutationListener(render(), () => {
+      listener.update(render())
+    })
+    tree.startMutationTracking()
+    state.foo = 'bar2'
+    tree.clearMutationTracking()
+    tree.flush()
+    expect(renderCount).toBe(2)
+  })
   test('should only trigger ones when multiple paths mutated', () => {
     let reactionCount = 0
     const tree = new ProxyStateTree({

packages/node_modules/proxy-state-tree/src/index.ts

@@ -34,34 +34,38 @@ class ProxyStateTree {
   get() {
     return this.proxy
   }
+  addTrackingPath(path) {
+    if (this.status === STATUS.TRACKING_PATHS) {
+      this.paths[this.paths.length - 1].add(path)
+    }
+  }
   flush() {
-    const pathCallbacksCalled = new Set()
+    const pathCallbacksToCall = new Set()
     const mutations = this.mutations.slice()
 
+    for (let objectChange of this.objectChanges) {
+      if (this.pathDependencies[objectChange]) {
+        for (let callback of this.pathDependencies[objectChange]) {
+          pathCallbacksToCall.add(callback)
+        }
+      }
+    }
+
     for (let mutation in this.mutations) {
       const path = this.mutations[mutation].path
 
       if (this.pathDependencies[path]) {
         for (let callback of this.pathDependencies[path]) {
-          if (!pathCallbacksCalled.has(callback)) {
-            pathCallbacksCalled.add(callback)
-            callback()
-          }
+          pathCallbacksToCall.add(callback)
         }
       }
     }
 
-    for (let objectChange of this.objectChanges) {
-      if (this.pathDependencies[objectChange]) {
-        for (let callback of this.pathDependencies[objectChange]) {
-          if (!pathCallbacksCalled.has(callback)) {
-            pathCallbacksCalled.add(callback)
-            callback()
-          }
-        }
-      }
+    for (let callback of pathCallbacksToCall) {
+      callback()
     }
-    pathCallbacksCalled.clear()
+
+    pathCallbacksToCall.clear()
     this.mutations.length = 0
     this.objectChanges.clear()