Add hasOwnProperty checks where appropriate #1189
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Don't we usually want: Instead of (Unless |
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Most (all?) of these things aren't supposed to have real prototype chains, so it's just a question of whether the property comes from Object.prototype. |
For boolean-like objects, I've added hasOwnProperty checks in addition to the existing truthiness check even though for most of these dicts, we leave out false keys instead of setting them explicitly to false. In DOMPropertyOperations, we don't need to check hasOwnProperty if the property is in isStandardName because (with the exception of getPossibleStandardName) the dicts on DOMProperty will now be consistently populated with every valid attribute.
| @@ -83,7 +83,7 @@ var ReactTransitionChildMapping = { | |||
| var i; | |||
| var childMapping = {}; | |||
| for (var nextKey in next) { | |||
| if (nextKeysPending[nextKey]) { | |||
| if (nextKeysPending.hasOwnProperty(nextKey)) { | |||
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Should some of these hasOwnProperty checks inside for-in loops be early continue instead of wrapping in a conditional? Now it is quite easy to still run some code after the conditional but still inside the for in loop, perhaps unintentionally? But I don't know those few places in this diff so well.
Add hasOwnProperty checks where appropriate
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Rebased & merged with 0c6bee0 |
| @@ -128,7 +128,7 @@ var topEventMapping = { | |||
| var topListenersIDKey = "_reactListenersID" + String(Math.random()).slice(2); | |||
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| function getListeningForDocument(mountAt) { | |||
| if (mountAt[topListenersIDKey] == null) { | |||
| if (!mountAt.hasOwnProperty(topListenersIDKey)) { | |||
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From @salier - "This is breaking in IE8, where mountAt is [object DispHTMLDocument]."
We can probably just revert this part.
For boolean-like objects, I've added hasOwnProperty checks in addition to the existing truthiness check even though for most of these dicts, we leave out false keys instead of setting them explicitly to false.
In DOMPropertyOperations, we don't need to check hasOwnProperty if the property is in isStandardName because (with the exception of getPossibleStandardName) the dicts on DOMProperty will now be consistently populated with every valid attribute.