Vérifiez si le document existe

bool docExists = await checkIfDocExists('document_id');
print("Document exists in Firestore? " + docExists.toString());

/// Check If Document Exists
Future<bool> checkIfDocExists(String docId) async {
  try {
    // Get reference to Firestore collection
    var collectionRef = Firestore.instance.collection('collectionName');

    var doc = await collectionRef.document(docId).get();
    return doc.exists;
  } catch (e) {
    throw e;
  }
}
//Good luck, firebase and flutter are awesome ;)
Steve