fix(zone.js): correctly patch es6 classes (#15)

Author: edusperoni

packages/zone-js/dist/core.ts

@@ -1,5 +1,5 @@
 /* eslint-disable */
-import { patchNativeScriptEventTarget } from './utils';
+import { patchClass, patchNativeScriptEventTarget } from './utils';
 
 function isPropertyWritable(propertyDesc: any) {
   if (!propertyDesc) {
@@ -49,3 +49,7 @@ Zone.__load_patch('nativescript_patchMethod', (global, Zone, api) => {
 Zone.__load_patch('nativescript_event_target_api', (g, z, api: any) => {
   api.patchNativeScriptEventTarget = patchNativeScriptEventTarget;
 });
+
+Zone.__load_patch('nativescript_patch_class_api', (g, z, api) => {
+  api.patchClass = (className: string) => patchClass(className, api);
+});

packages/zone-js/dist/index.ts

@@ -1,4 +1,5 @@
 import './core';
+import './nativescript-globals';
 import './events';
 import './xhr';
 import './connectivity';

packages/zone-js/dist/nativescript-globals.ts

@@ -0,0 +1,12 @@
+// Zone.__load_patch('nativescript_MutationObserver', (global: any, Zone: ZoneType, api: _ZonePrivate) => {
+//   api.patchClass('MutationObserver');
+//   api.patchClass('WebKitMutationObserver');
+// });
+
+// Zone.__load_patch('nativescript_IntersectionObserver', (global: any, Zone: ZoneType, api: _ZonePrivate) => {
+//   api.patchClass('IntersectionObserver');
+// });
+
+Zone.__load_patch('nativescript_FileReader', (global: any, Zone: ZoneType, api: _ZonePrivate) => {
+  api.patchClass('FileReader');
+});

packages/zone-js/dist/pre-zone-polyfills.ts

@@ -1,3 +1,5 @@
-global['__Zone_disable_legacy'] = true;
-global['__Zone_disable_EventTarget'] = true;
-global['__Zone_disable_XHR'] = true;
+export const disabledPatches = ['legacy', 'EventTarget', 'XHR', 'MutationObserver', 'IntersectionObserver', 'FileReader'];
+
+for (const patch of disabledPatches) {
+  global[`__Zone_disable_${patch}`] = true;
+}

packages/zone-js/dist/utils.ts

@@ -331,3 +331,93 @@ export function patchNativeScriptEventTarget(global: any, api: _ZonePrivate, api
 
   return results;
 }
+
+const _global = global;
+
+const zoneSymbol = Zone.__symbol__;
+
+const originalInstanceKey = zoneSymbol('originalInstance');
+
+function getAllPropertyNames(obj: unknown) {
+  const props = new Set<string>();
+
+  do {
+    Object.getOwnPropertyNames(obj).forEach((prop) => {
+      props.add(prop);
+    });
+  } while ((obj = Object.getPrototypeOf(obj)) && obj !== Object.prototype);
+
+  return Array.from(props);
+}
+
+// wrap some native API on `window`
+export function patchClass(className: string, api: _ZonePrivate) {
+  const OriginalClass = _global[className];
+  if (!OriginalClass) return;
+  // keep original class in global
+  _global[zoneSymbol(className)] = OriginalClass;
+
+  _global[className] = function () {
+    const a = api.bindArguments(<any>arguments, className);
+    switch (a.length) {
+      case 0:
+        this[originalInstanceKey] = new OriginalClass();
+        break;
+      case 1:
+        this[originalInstanceKey] = new OriginalClass(a[0]);
+        break;
+      case 2:
+        this[originalInstanceKey] = new OriginalClass(a[0], a[1]);
+        break;
+      case 3:
+        this[originalInstanceKey] = new OriginalClass(a[0], a[1], a[2]);
+        break;
+      case 4:
+        this[originalInstanceKey] = new OriginalClass(a[0], a[1], a[2], a[3]);
+        break;
+      default:
+        throw new Error('Arg list too long.');
+    }
+  };
+
+  // attach original delegate to patched function
+  api.attachOriginToPatched(_global[className], OriginalClass);
+
+  const instance = new OriginalClass(function () {});
+
+  let prop;
+  for (prop of Object.getOwnPropertyNames(instance)) {
+    // https://bugs.webkit.org/show_bug.cgi?id=44721
+    if (className === 'XMLHttpRequest' && prop === 'responseBlob') continue;
+    (function (prop) {
+      if (typeof instance[prop] === 'function') {
+        _global[className].prototype[prop] = function () {
+          return this[originalInstanceKey][prop].apply(this[originalInstanceKey], arguments);
+        };
+      } else {
+        api.ObjectDefineProperty(_global[className].prototype, prop, {
+          set: function (fn) {
+            if (typeof fn === 'function') {
+              this[originalInstanceKey][prop] = api.wrapWithCurrentZone(fn, className + '.' + prop);
+              // keep callback in wrapped function so we can
+              // use it in Function.prototype.toString to return
+              // the native one.
+              api.attachOriginToPatched(this[originalInstanceKey][prop], fn);
+            } else {
+              this[originalInstanceKey][prop] = fn;
+            }
+          },
+          get: function () {
+            return this[originalInstanceKey][prop];
+          },
+        });
+      }
+    })(prop);
+  }
+
+  for (prop in Object.getOwnPropertyNames(OriginalClass)) {
+    if (prop !== 'prototype' && OriginalClass.hasOwnProperty(prop)) {
+      _global[className][prop] = OriginalClass[prop];
+    }
+  }
+}