User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:46.0) Gecko/20100101 Firefox/46.0 Build ID: 20160121030208 Steps to reproduce: 1. Start Nightly (or Aurora) 2. Open Memory tool 3. Repeat "Take Snapshot..." twice 4. Click "Compare Snapshot" button 5. Select baseline and comparison 6. Check on "Invert tree" 7. Switch the group by from "Coarse Type" to "Allocation Stack" Actual results: Difference calculation does not end. Expected results: Difference calculation is completed.

From what I tested, the issue only occurs if the two snapshots are identical. If there is any difference displayed, the calculation ends properly.

Is this what you mean? Not that there is a spinner forever? If so, this is what happens when the snapshots are identical, as Julian mentions. I think we could have a better UI by displaying a message saying something like "no difference between the snapshots" or something along those lines.

(In reply to Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8] from comment #2) > Created attachment 8711058 [details] > Screen Shot 2016-01-22 at 8.49.02 AM.png > > Is this what you mean? Not that there is a spinner forever? Yes. And there is no error message in the Browser Console. 06:00:24.717 @@redux/middleware/task#error threw an exception: TypeError: census.report.children is undefined Stack: _renderCensus@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/memory/components/heap.js:258:1 render@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/memory/components/heap.js:184:14 [38]</ReactCompositeComponentMixin._renderValidatedComponentWithoutOwnerOrContext@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6337:29 [38]</ReactCompositeComponentMixin._renderValidatedComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6357:27 [38]</ReactCompositeComponentMixin._updateRenderedComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6310:31 [38]</ReactCompositeComponentMixin._performComponentUpdate@resource://gre/modules/commonjs/toolkit/loader.js -> re DevToolsUtils.js:69:0 06:00:24.721 Handler function threw an exception: TypeError: census.report.children is undefined Stack: _renderCensus@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/memory/components/heap.js:258:1 render@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/memory/components/heap.js:184:14 [38]</ReactCompositeComponentMixin._renderValidatedComponentWithoutOwnerOrContext@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6337:29 [38]</ReactCompositeComponentMixin._renderValidatedComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6357:27 [38]</ReactCompositeComponentMixin._updateRenderedComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6310:31 [38]</ReactCompositeComponentMixin._performComponentUpdate@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6294:5 [38]</ReactCompositeComponentMixin.updateComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6223:7 [38]</ReactCompositeComponentMixin.receiveComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6155:5 [84]</ReactReconciler.receiveComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:13661:5 [31]</ReactChildReconciler.updateChildren@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:4492:9 [73]</ReactMultiChild.Mixin._reconcilerUpdateChildren@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:12195:14 [73]</ReactMultiChild.Mixin._updateChildren@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:12326:26 [73]</ReactMultiChild.Mixin.updateChildren@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:12301:9 [42]</ReactDOMComponent.Mixin._updateDOMChildren@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:7491:7 [42]</ReactDOMComponent.Mixin.updateComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:7320:5 [42]</ReactDOMComponent.Mixin.receiveComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:7265:5 [84]</ReactReconciler.receiveComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:13661:5 [31]</ReactChildReconciler.updateChildren@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:4492:9 [73]</ReactMultiChild.Mixin._reconcilerUpdateChildren@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:12195:14 [73]</ReactMultiChild.Mixin._updateChildren@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:12326:26 [73]</ReactMultiChild.Mixin.updateChildren@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:12301:9 [42]</ReactDOMComponent.Mixin._updateDOMChildren@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:7491:7 [42]</ReactDOMComponent.Mixin.updateComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:7320:5 [42]</ReactDOMComponent.Mixin.receiveComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:7265:5 [84]</ReactReconciler.receiveComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:13661:5 [38]</ReactCompositeComponentMixin._updateRenderedComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6312:7 [38]</ReactCompositeComponentMixin._performComponentUpdate@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6294:5 [38]</ReactCompositeComponentMixin.updateComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6223:7 [38]</ReactCompositeComponentMixin.receiveComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6155:5 [84]</ReactReconciler.receiveComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:13661:5 [38]</ReactCompositeComponentMixin._updateRenderedComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6312:7 [38]</ReactCompositeComponentMixin._performComponentUpdate@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6294:5 [38]</ReactCompositeComponentMixin.updateComponent@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6223:7 [38]</ReactCompositeComponentMixin.performUpdateIfNecessary@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:6171:7 [84]</ReactReconciler.performUpdateIfNecessary@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:13676:5 runBatchedUpdates@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:15368:5 [113]</Mixin.perform@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:17257:13 [113]</Mixin.perform@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:17257:13 [96]</<.perform@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:15325:12 [96]</flushBatchedUpdates@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:15386:7 [113]</Mixin.closeAll@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:17323:11 [113]</Mixin.perform@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:17270:11 [53]</ReactDefaultBatchingStrategy.batchedUpdates@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:8849:7 enqueueUpdate@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:15415:5 enqueueUpdate@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:15005:3 [95]</ReactUpdateQueue.enqueueSetState@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:15171:5 [34]</ReactComponent.prototype.setState@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react.js:5551:3 handleChange@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/react-redux.js:346:12 createStore/dispatch/<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/redux.js:212:15 dispatch@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/redux.js:211:6 waitUntilService/</<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/redux/middleware/wait-service.js:60:20 promiseMiddleware/</<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/redux/middleware/promise.js:16:14 thunk/</<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/redux/middleware/thunk.js:16:9 task/</<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/redux/middleware/task.js:31:12 dispatch@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/vendor/redux.js:384:19 handleError/<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/client/shared/redux/middleware/task.js:38:5 makeInfallible/<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/DevToolsUtils.js:93:14 Line: 258, column: 1 DevToolsUtils.js:69:0 > If so, this is what happens when the snapshots are identical, as Julian > mentions. I think we could have a better UI by displaying a message saying > something like "no difference between the snapshots" or something along > those lines. It sounds good.

We have also since fixed the forever spinner issue caused by accessing census.report.children without null-checking, but I still think it would be good to have a placeholder as mentioned above.

We already have tests that we don't throw when receiving empty censuses, didn't feel an overwhelming need to test that we show the empty message too. If you feel otherwise, I can write up a test. Try push: https://treeherder.mozilla.org/#/jobs?repo=try&revision=a8b776114ebd

Comment on attachment 8733624 [details] [diff] [review] Show a message when filtering yields no matches I'll not be lazy and write a test. Its the right thing to do.

Now with test!

Try push: https://treeherder.mozilla.org/#/jobs?repo=try&revision=0dfe9163b087