Generic Firestore Service for Angular (Firebase SDK 10+)

firestore.service.ts

// Tested in Angular 17+ with Firebase SDK 10+

import { Injectable, inject } from '@angular/core';
import { Firestore, QueryConstraint, collection, getDocs } from '@angular/fire/firestore';
import { CollectionReference, addDoc, deleteDoc, doc, getDoc, query, setDoc, updateDoc } from '@firebase/firestore';
import { Observable, from, map } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class FirestoreService {
  private firestore = inject(Firestore);

  // Usage: this.firestoreService.list<*InterfaceName*>('*Collection*', *Queries Separated With Comma* );
  list<T>(path: string, ...q: QueryConstraint[]): Observable<T[]> {
    const collectionRef = collection(this.firestore, path) as CollectionReference<T>;
    const qRef = query(collectionRef, ...q);
    return from(getDocs(qRef)).pipe(
      map(snapshot => snapshot.docs.map(doc => ({ id: doc.id, ...doc.data() } as T)))
    );
  }

  add(path: string, data: any) {
    const ref = collection(this.firestore, path);
    return addDoc(ref, this.setUndefinedValuesToNull(data));
  }

  set(path: string, data: any) {
    const ref = doc(this.firestore, path);
    return setDoc(ref, this.setUndefinedValuesToNull(data), { merge: true });
  }

  get(path: string) {
    const ref = doc(this.firestore, path);
    return getDoc(ref);
  }

  update(path: string, data: any) {
    const ref = doc(this.firestore, path);
    return updateDoc(ref, this.setUndefinedValuesToNull(data));
  }

  delete(path: string) {
    const ref = doc(this.firestore, path);
    return deleteDoc(ref);
  }

  setUndefinedValuesToNull(data: any) {
    Object.keys(data).filter(k => data[k] == undefined).forEach(k => data[k] = null);
    return data;
  }
}