feat(longStackTraceSpec): handled promise rejection can also render longstacktrace (#631)

Author: JiaLiPassion

lib/zone-spec/long-stack-trace.ts

@@ -27,18 +27,18 @@ function getStacktraceWithUncaughtError(): Error {
 function getStacktraceWithCaughtError(): Error {
   try {
     throw getStacktraceWithUncaughtError();
-  } catch (error) {
-    return error;
+  } catch (err) {
+    return err;
   }
 }
 
 // Some implementations of exception handling don't create a stack trace if the exception
 // isn't thrown, however it's faster not to actually throw the exception.
 const error = getStacktraceWithUncaughtError();
-const coughtError = getStacktraceWithCaughtError();
+const caughtError = getStacktraceWithCaughtError();
 const getStacktrace = error.stack ?
     getStacktraceWithUncaughtError :
-    (coughtError.stack ? getStacktraceWithCaughtError : getStacktraceWithUncaughtError);
+    (caughtError.stack ? getStacktraceWithCaughtError : getStacktraceWithUncaughtError);
 
 function getFrames(error: Error): string[] {
   return error.stack ? error.stack.split(NEWLINE) : [];
@@ -77,6 +77,19 @@ function renderLongStackTrace(frames: LongStackTrace[], stack: string): string {
 Zone['longStackTraceZoneSpec'] = <ZoneSpec>{
   name: 'long-stack-trace',
   longStackTraceLimit: 10,  // Max number of task to keep the stack trace for.
+  // add a getLongStackTrace method in spec to
+  // handle handled reject promise error.
+  getLongStackTrace: function(error: Error): string {
+    if (!error) {
+      return undefined;
+    }
+    const task = error[Zone['__symbol__']('currentTask')];
+    const trace = task && task.data && task.data[creationTrace];
+    if (!trace) {
+      return error.stack;
+    }
+    return renderLongStackTrace(trace, error.stack);
+  },
 
   onScheduleTask: function(
       parentZoneDelegate: ZoneDelegate, currentZone: Zone, targetZone: Zone, task: Task): any {

lib/zone.ts

@@ -1332,6 +1332,12 @@ const Zone: ZoneType = (function(global: any) {
         const queue = promise[symbolValue];
         promise[symbolValue] = value;
 
+        // record task information in value when error occurs, so we can
+        // do some additional work such as render longStackTrace
+        if (state === REJECTED && value instanceof Error) {
+          value[__symbol__('currentTask')] = Zone.currentTask;
+        }
+
         for (let i = 0; i < queue.length;) {
           scheduleResolveOrReject(promise, queue[i++], queue[i++], queue[i++], queue[i++]);
         }

test/zone-spec/long-stack-trace-zone.spec.ts

@@ -12,9 +12,10 @@ const defineProperty = Object[zoneSymbol('defineProperty')] || Object.defineProp
 describe('longStackTraceZone', function() {
   let log: Error[];
   let lstz: Zone;
+  let longStackTraceZoneSpec = Zone['longStackTraceZoneSpec'];
 
   beforeEach(function() {
-    lstz = Zone.current.fork(Zone['longStackTraceZoneSpec']).fork({
+    lstz = Zone.current.fork(longStackTraceZoneSpec).fork({
       name: 'long-stack-trace-zone-test',
       onHandleError: (parentZoneDelegate: ZoneDelegate, currentZone: Zone, targetZone: Zone,
                       error: any): boolean => {
@@ -67,7 +68,7 @@ describe('longStackTraceZone', function() {
     });
   });
 
-  it('should produce long stack traces when reject in promise', function(done) {
+  it('should produce long stack traces when has uncaught error in promise', function(done) {
     lstz.runGuarded(function() {
       setTimeout(function() {
         setTimeout(function() {
@@ -91,6 +92,26 @@ describe('longStackTraceZone', function() {
       }, 0);
     });
   });
+
+  it('should produce long stack traces when handling error in promise', function(done) {
+    lstz.runGuarded(function() {
+      setTimeout(function() {
+        setTimeout(function() {
+          let promise = new Promise(function(resolve, reject) {
+            setTimeout(function() {
+              reject(new Error('Hello Promise'));
+            }, 0);
+          });
+          promise.catch(function(error) {
+            // should be able to get long stack trace
+            const longStackFrames: string = longStackTraceZoneSpec.getLongStackTrace(error);
+            expect(longStackFrames.split('Elapsed: ').length).toBe(4);
+            done();
+          });
+        }, 0);
+      }, 0);
+    });
+  });
 });
 
 export let __something__;