feat(proxy-state-tree): allow callback to run logic after all tracking is done

Author: christianalfoni

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

@@ -24,6 +24,21 @@ describe('CREATION', () => {
   })
 })
 
+describe('TRACKING', () => {
+  test('should allow callback to run when tracking is finished', () => {
+    let hasCalledCb = false
+    const tree = new ProxyStateTree({})
+    const trackId = tree.startPathsTracking()
+    const trackId2 = tree.startPathsTracking()
+    tree.clearPathsTracking(trackId2, () => {
+      hasCalledCb = true
+    })
+    expect(hasCalledCb).toBe(false)
+    tree.clearPathsTracking(trackId)
+    expect(hasCalledCb).toBe(true)
+  })
+})
+
 describe('OBJECTS', () => {
   describe('ACCESS', () => {
     test('should create proxy when accessed', () => {

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

@@ -21,6 +21,7 @@ class ProxyStateTree {
   private paths: Set<string>[] = []
   private status: STATUS = STATUS.IDLE
   private currentFlushId: number = 0
+  private completedTrackingCallbacks = []
   private proxy: any
   constructor(private state: object, private options: Options = {}) {
     if (!isPlainObject(state)) {
@@ -118,15 +119,22 @@ class ProxyStateTree {
 
     return this.paths.push(new Set()) - 1
   }
-  clearPathsTracking(index: number) {
+  clearPathsTracking(index: number, cb?: () => void) {
     const pathSet = this.paths.splice(index, 1, null)[0]
 
     while (this.paths[this.paths.length - 1] === null) {
       this.paths.pop()
     }
 
+    if (cb) {
+      this.completedTrackingCallbacks.push(cb)
+    }
+
     if (!this.paths.length) {
       this.status = STATUS.IDLE
+      while (this.completedTrackingCallbacks.length) {
+        this.completedTrackingCallbacks.shift()()
+      }
     }
 
     return pathSet