[BUGFIX release] Consumes tags after fully getting values #18668
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Currently get() consumes some tags before getting the values, and getting the values itself can cause tag changes and notifications. In some cases, this is invalid, because the value that is being notified hasn't actually been consumed yet (it is in the process of being consumed. More generally, consumption should always occur immediately _after_ the relevant calculation - in this case, the getter.
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looks like machty/ember-concurrency#337 may be related |
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Thanks, this seems to solve emberjs/data#6943 . Is there a plan on when this will be merged? |
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| }, /You attempted to update `foo` on `EmberObject`, but it had already been used previously in the same computation/); | |||
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| ['@test get() does not entangle in the autotracking stack until after retrieving the value']( | |||
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Can you explain this test? How did it fail before? How does it confirm what it says it is confirming?
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Before, get would consume the tag for the property immediately, then actually get the value of the property. If the property signaled a change via notifyPropertyChange in this time, it would throw the backtracking assertion. This is the fundamental problem that led to the bug in Ember Data.
After, we consume all tags for the first time after getting resolved values, whatever they end up being, which means it is safe to signal property changes while calculating the value.
Currently get() consumes some tags before getting the values,
and getting the values itself can cause tag changes and notifications.
In some cases, this is invalid, because the value that is being notified
hasn't actually been consumed yet (it is in the process of being
consumed. More generally, consumption should always occur immediately
after the relevant calculation - in this case, the getter.