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fix(core): ObservableArray tests and a typo (#8968)

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This commit is contained in:
Nathanael Anderson
2020-10-17 18:07:03 -05:00
committed by Nathan Walker
parent 0afea8681c
commit 5c1b7f6d76
3 changed files with 117 additions and 3 deletions
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17
packages/core/data/observable-array/index.ts
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@ -32,6 +32,7 @@ export interface ChangedData<T> extends EventData {
* Number of added items.
*/
addedCount: number;
}
const CHANGE = 'change';
@ -113,7 +114,11 @@ export class ObservableArray<T> extends Observable {
set length(value: number) {
if (types.isNumber(value) && this._array && this._array.length !== value) {
this.splice(value, this._array.length - value);
let added=[];
for (let i=this._array.length;i < value;++i) {
added.push(undefined);
}
this.splice(value, this._array.length - value, ...added);
}
}
@ -246,7 +251,15 @@ export class ObservableArray<T> extends Observable {
eventName: CHANGE,
object: this,
action: ChangeType.Splice,
index: Math.max(Math.min(start, this._array.length-1), 0),
// The logic here is a bit weird; so lets explain why it is written this way
// First of all, if you ADD any items to the array, we want the index to point to
// the first value of the index, so this fixes it when you put a value to high in
// If you remove items from the array, then the index needs to point to the INDEX
// where you removed the item.
// If you add and remove items, the index will point to the remove location as that
// is the index you passed in.
index: Math.max(Math.min(start, length - (result.length > 0 ? 1 : 0)), 0),
removed: result,
addedCount: this._array.length + result.length - length,
});