fix(zone.js): patch fs.realpath.native as macrotask (#54208)

This commit updates the implementation of the zone.js `fs` patch to
restore the implementation of `realpath.native` and patches it as a macrotask,
along with other functions of the `fs` package. This is the only nested function
that must be patched.

Closes: #45546

PR Close #54208

packages/zone.js/lib/node/fs.ts

@@ -6,15 +6,17 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {patchMacroTask} from '../common/utils';
+import {patchMacroTask, zoneSymbol} from '../common/utils';
 
-Zone.__load_patch('fs', () => {
+Zone.__load_patch('fs', (global: any, Zone: ZoneType, api: _ZonePrivate) => {
   let fs: any;
   try {
     fs = require('fs');
   } catch (err) {
   }
 
+  if (!fs) return;
+
   // watch, watchFile, unwatchFile has been patched
   // because EventEmitter has been patched
   const TO_PATCH_MACROTASK_METHODS = [
@@ -25,17 +27,28 @@ Zone.__load_patch('fs', () => {
     'symlink', 'truncate',   'unlink',   'utimes',   'write',     'writeFile',
   ];
 
-  if (fs) {
-    TO_PATCH_MACROTASK_METHODS.filter(name => !!fs[name] && typeof fs[name] === 'function')
-        .forEach(name => {
-          patchMacroTask(fs, name, (self: any, args: any[]) => {
-            return {
-              name: 'fs.' + name,
-              args: args,
-              cbIdx: args.length > 0 ? args.length - 1 : -1,
-              target: self
-            };
-          });
+  TO_PATCH_MACROTASK_METHODS.filter(name => !!fs[name] && typeof fs[name] === 'function')
+      .forEach(name => {
+        patchMacroTask(fs, name, (self: any, args: any[]) => {
+          return {
+            name: 'fs.' + name,
+            args: args,
+            cbIdx: args.length > 0 ? args.length - 1 : -1,
+            target: self
+          };
         });
+      });
+
+  const realpathOriginalDelegate = fs.realpath?.[api.symbol('OriginalDelegate')];
+  // This is the only specific method that should be additionally patched because the previous
+  // `patchMacroTask` has overridden the `realpath` function and its `native` property.
+  if (realpathOriginalDelegate?.native) {
+    fs.realpath.native = realpathOriginalDelegate.native;
+    patchMacroTask(fs.realpath, 'native', (self, args) => ({
+      args,
+      target: self,
+      cbIdx: args.length > 0 ? args.length - 1 : -1,
+      name: 'fs.realpath.native',
+    }));
   }
 });

packages/zone.js/test/node/fs.spec.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {closeSync, exists, fstatSync, openSync, read, unlink, unlinkSync, unwatchFile, watch, watchFile, write, writeFile} from 'fs';
+import {closeSync, exists, fstatSync, openSync, read, realpath, unlink, unlinkSync, unwatchFile, watch, watchFile, write, writeFile} from 'fs';
 import url from 'url';
 import util from 'util';
 
@@ -41,6 +41,50 @@ describe('nodejs file system', () => {
         });
       });
     });
+
+    it('has patched realpath as macroTask', (done) => {
+      const testZoneSpec = {
+        name: 'test',
+        onScheduleTask: (delegate: ZoneDelegate, currentZone: Zone, targetZone: Zone, task: Task):
+            Task => {
+              return delegate.scheduleTask(targetZone, task);
+            }
+      };
+      const testZone = Zone.current.fork(testZoneSpec);
+      spyOn(testZoneSpec, 'onScheduleTask').and.callThrough();
+      testZone.run(() => {
+        realpath('testfile', () => {
+          expect(Zone.current).toBe(testZone);
+          expect(testZoneSpec.onScheduleTask).toHaveBeenCalled();
+          done();
+        });
+      });
+    });
+
+    // https://github.com/angular/angular/issues/45546
+    // Note that this is intentionally marked with `xit` because `realpath.native`
+    // is patched by Bazel's `node_patches.js` and doesn't allow further patching
+    // of `realpath.native` in unit tests. Essentially, there's no original delegate
+    // for `realpath` because it's also patched. The code below functions correctly
+    // in the actual production environment.
+    xit('has patched realpath.native as macroTask', (done) => {
+      const testZoneSpec = {
+        name: 'test',
+        onScheduleTask: (delegate: ZoneDelegate, currentZone: Zone, targetZone: Zone, task: Task):
+            Task => {
+              return delegate.scheduleTask(targetZone, task);
+            }
+      };
+      const testZone = Zone.current.fork(testZoneSpec);
+      spyOn(testZoneSpec, 'onScheduleTask').and.callThrough();
+      testZone.run(() => {
+        realpath.native('testfile', () => {
+          expect(Zone.current).toBe(testZone);
+          expect(testZoneSpec.onScheduleTask).toHaveBeenCalled();
+          done();
+        });
+      });
+    });
   });
 
   describe('watcher related methods test', () => {
@@ -108,6 +152,32 @@ describe('util.promisify', () => {
             });
   });
 
+  it('fs.realpath should work with util.promisify', (done: DoneFn) => {
+    const promisifyRealpath = util.promisify(realpath);
+    promisifyRealpath(currentFile)
+        .then(
+            r => {
+              expect(r).toBeDefined();
+              done();
+            },
+            err => {
+              fail(`should not be here with error: ${err}`);
+            });
+  });
+
+  it('fs.realpath.native should work with util.promisify', (done: DoneFn) => {
+    const promisifyRealpathNative = util.promisify(realpath.native);
+    promisifyRealpathNative(currentFile)
+        .then(
+            r => {
+              expect(r).toBeDefined();
+              done();
+            },
+            err => {
+              fail(`should not be here with error: ${err}`);
+            });
+  });
+
   it('fs.read should work with util.promisify', (done: DoneFn) => {
     const promisifyRead = util.promisify(read);
     const fd = openSync(currentFile, 'r');