I managed to write code which does what I need, but I want to make it clean and remove mutation of realtiveGroups.push() but don't know how to achieve it. How to remove mutation from this code?
export interface OfferCategory {
id: string;
name: string;
}
export interface OfferGroup {
groupId: string;
dependsOn: OfferCategory;
name: string;
rule: Rule;
products: PosProducts[];
}
function relativesFromSubscription(groups: OfferGroup[], dependingGroups: OfferGroup[]): OfferGroup[] {
const relativeGroups: OfferGroup[] = [];
groups.forEach(group => {
if (dependingGroups.some(dependingGroup => group?.dependsOn?.id === dependingGroup.groupId)) {
relativeGroups.push(group);
}
if (relativeGroups.some(relativeGroup => group?.dependsOn?.id === relativeGroup.groupId)) {
relativeGroups.push(group);
}
});
return relativeGroups;
}
Instead of doing everything in one cycle try dividing it into a few:
function relativesFromSubscription(groups: OfferGroup[], dependingGroups: OfferGroup[]): OfferGroup[] {
const groups1 = groups.filter(group => dependingGroups.some(dependingGroup => group?.dependsOn?.id === dependingGroup.groupId));
const groups2 = groups.filter(group => groups1.some(relGroup=> group?.dependsOn?.id === relGroup.groupId));
return [...groups1, ...groups2];
}
Using your code and Array.filter
const relativeGroups: OfferGroup[] = groups.filter(group => {
return dependingGroups.some(dependingGroup => group?.dependsOn?.id === dependingGroup.groupId) || relativeGroups.some(relativeGroup => group?.dependsOn?.id === relativeGroup.groupId)
});
Or if you want the code to be more readable you can add descriptive variables:
const relativeGroups: OfferGroup[] = groups.filter(group => {
const hasDependingGroups = dependingGroups.some(dependingGroup => group?.dependsOn?.id === dependingGroup.groupId);
const hasRelativeGroups = relativeGroups.some(relativeGroup => group?.dependsOn?.id === relativeGroup.groupId)
return hasDependingGroups || hasRelativeGroups
});