fix(scope): Use runAsync for microtasks in digest.

BREAKING CHANGE: Microtasks scheduled in flush will process in current cycle, but they are not allowed to do model changes. Microtasks scheduled in digest will be executed in digest, counting towards the ScopeDigestTTL.
dart-archive · Jun 11, 2014 · d1e745e · d1e745e · jbdeboer · Jun 23, 2014
1 parent 81667aa
commit d1e745e
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Showing 2 changed files with 46 additions and 16 deletions.
diff --git a/lib/core/scope.dart b/lib/core/scope.dart
@@ -680,15 +680,8 @@ class RootScope extends Scope {
       ChangeLog changeLog;
       _scopeStats.digestStart();
       do {
-        while (_runAsyncHead != null) {
-          try {
-            _runAsyncHead.fn();
-          } catch (e, s) {
-            _exceptionHandler(e, s);
-          }
-          _runAsyncHead = _runAsyncHead._next;
-        }
-        _runAsyncTail = null;
+
+        int asyncCount = _runAsyncFns();
 
         digestTTL--;
         count = rootWatchGroup.detectChanges(
@@ -704,7 +697,7 @@ class RootScope extends Scope {
             digestLog = [];
             changeLog = (e, c, p) => digestLog.add('$e: $c <= $p');
           } else {
-            log.add(digestLog.join(', '));
+            log.add("${asyncCount > 0 ? 'async:$asyncCount' : ''}${digestLog.join(', ')}");
             digestLog.clear();
           }
         }
@@ -713,7 +706,7 @@ class RootScope extends Scope {
                 'Last $LOG_COUNT iterations:\n${log.join('\n')}';
         }
         _scopeStats.digestLoop(count);
-      } while (count > 0);
+      } while (count > 0 || _runAsyncHead != null);
     } finally {
       _scopeStats.digestEnd();
       _transitionState(STATE_DIGEST, null);
@@ -756,7 +749,8 @@ class RootScope extends Scope {
           if (_domReadHead == null) _stats.domReadEnd();
         }
         _domReadTail = null;
-      } while (_domWriteHead != null || _domReadHead != null);
+        _runAsyncFns();
+      } while (_domWriteHead != null || _domReadHead != null || _runAsyncHead != null);
       _stats.flushEnd();
       assert((() {
         _stats.flushAssertStart();
@@ -788,7 +782,7 @@ class RootScope extends Scope {
 
   // QUEUES
   void runAsync(fn()) {
-    if (_state == STATE_FLUSH || _state == STATE_FLUSH_ASSERT) {
+    if (_state == STATE_FLUSH_ASSERT) {
       throw "Scheduling microtasks not allowed in $state state.";
     }
     var chain = new _FunctionChain(fn);
@@ -799,6 +793,21 @@ class RootScope extends Scope {
     }
   }
 
+  _runAsyncFns() {
+    var count = 0;
+    while (_runAsyncHead != null) {
+      try {
+        count++;
+        _runAsyncHead.fn();
+      } catch (e, s) {
+        _exceptionHandler(e, s);
+      }
+      _runAsyncHead = _runAsyncHead._next;
+    }
+    _runAsyncTail = null;
+    return count;
+  }
+
   void domWrite(fn()) {
     var chain = new _FunctionChain(fn);
     if (_domWriteHead == null) {

diff --git a/test/core/scope_spec.dart b/test/core/scope_spec.dart
@@ -1227,6 +1227,20 @@ void main() {
       });
 
 
+      it(r'should detect infinite digest through runAsync', (RootScope rootScope) {
+        rootScope.context['value'] = () { rootScope.runAsync(() {}); return 'a'; };
+        rootScope.watch('value()', (_, __) {});
+
+        expect(() {
+          rootScope.digest();
+        }).toThrow('Model did not stabilize in 5 digests. '
+        'Last 3 iterations:\n'
+        'async:1\n'
+        'async:1\n'
+        'async:1');
+      });
+
+
       it(r'should always call the watchr with newVal and oldVal equal on the first run',
       inject((RootScope rootScope) {
         var log = [];
@@ -1500,15 +1514,22 @@ void main() {
         })
       );
 
-      it('should not allow microtasks in flush phase',
+      it('should allow microtasks in flush phase and process them immediatly',
         async((Logger log, VmTurnZone zone, RootScope scope) {
+          scope.watch('g()', (_, __) {});
+          scope.context['g'] = () {
+            log('!');
+            return 0;
+          };
+
           zone.run(() {
             scope.domWrite(() {
-              return new Future.value('FAIL');
+              log('domWriteA');
+              return new Future.value(null).then((_) => scope.domWrite(() => log('domWriteB')));
             });
           });
           expect(log).toEqual(
-              ['[', '(', 'CATCH: Scheduling microtasks not allowed in flush state.', ')', ']']);
+              ['[', '!', '!', 'domWriteA', '(', ')', 'domWriteB', /* assert */'!', ']']);
         })
       );