insert
insert
Inserts one or multiple items to an array T[]. Returns a shallow copy of the updated array T[], and does not mutate the original one.
Example
// Inserting single value
const creatures = [
{ id: 1, type: 'cat' },
{ id: 2, type: 'dog' },
];
const updatedCreatures = insert(creatures, { id: 3, type: 'parrot' });
// updatedCreatures will be:
// [{id: 1, type: 'cat'}, {id: 2, type: 'dog}, {id: 3, type: 'parrot}];
Example
// Inserting multiple values
const creatures = [
{ id: 1, type: 'cat' },
{ id: 2, type: 'dog' },
];
const updatedCreatures = insert(creatures, [
{ id: 3, type: 'parrot' },
{ id: 4, type: 'hamster' },
]);
// updatedCreatures will be:
// [{id: 1, type: 'cat'}, {id: 2, type: 'dog'}, {id: 3, type: 'parrot'}, {id: 4, type: 'hamster'}];
Example
// Usage with RxState
export class ListComponent {
readonly insertCreature$ = new Subject<void>();
constructor(private state: RxState<ComponentState>) {
// Reactive implementation
state.connect('creatures', this.insertCreature$, ({ creatures }) => {
const creatureToAdd = {
id: generateId(),
name: 'newCreature',
type: 'dinosaur',
};
return insert(creatures, creatureToAdd);
});
}
// Imperative implementation
insertCreature(): void {
const creatureToAdd = {
id: generateId(),
name: 'newCreature',
type: 'dinosaur',
};
this.state.set({
creatures: insert(this.state.get().creatures, creatureToAdd),
});
}
}
Edge cases
insert(null as any, items) > items;
insert(items, null as any) > items;
insert(null as any, null as any) > null;
insert(undefined as any, undefined as any) > undefined;
insert(nonArray as any, items) > items;
Signature
function insert<T>(source: T[], updates: T | T[]): T[];