loucou

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    match /junction_student_course/{junctionId} {
      allow read:
        if request.auth != null 
        && request.auth.uid == resource.data.studentId;
      
      allow create:
        if request.auth != null

loucou

async function attendCourse(studentId, courseId) {
  const attendingRef = db.doc(`students/${studentId}/attending/${courseId}`);
  const attendeeRef = db.doc(`courses/${courseId}/attendees/${studentId}`);

  const batch = db.batch();
  batch.set(attendingRef, {});
  batch.set(attendeeRef, {});
  await batch.commit();
}

loucou

function countListener(onCountChange: (count: number) => void) {
    const query = firebase.firestore().collection("fruits");
    let count = 0;
    return query.onSnapshot(snapshot => {
        snapshot.docChanges().forEach(change => {
            if (change.type === "added") onCountChange(++count);
            if (change.type === "removed") onCountChange(--count);
        });
    });
}

loucou

const admin = require("firebase-admin");

process.env["FIRESTORE_EMULATOR_HOST"] = "localhost:8080";

const serviceAccountKey = require("./serviceAccountKey.json");

admin.initializeApp({
    credential: admin.credential.cert(serviceAccountKey),
    databaseURL: `https://${serviceAccountKey.project_id}.firebaseio.com`,
});