const should = require('should');

describe('firestore()', () => {
  describe('runTransaction()', () => {
    it('should set, update and delete transactionally and allow a return value', async () => {
      let deleteMe = false;
      const firestore = firebase.firestore();

      const docRef = firestore
        .collection('transactions')
        .doc(Date.now().toString());

      const updateFunction = async transaction => {
        const doc = await transaction.get(docRef);
        if (doc.exists && deleteMe) {
          transaction.delete(docRef);
          return 'bye';
        }

        if (!doc.exists) {
          transaction.set(docRef, { value: 1 });
          return 1;
        }

        const newValue = doc.data().value + 1;

        if (newValue > 2) {
          return Promise.reject(
            new Error('Value should not be greater than 2!')
          );
        }

        transaction.update(docRef, {
          value: newValue,
          somethingElse: 'update',
        });

        return newValue;
      };

      // set tests
      const val1 = await firestore.runTransaction(updateFunction);
      should.equal(val1, 1);
      const doc1 = await docRef.get();
      doc1.data().value.should.equal(1);
      should.equal(doc1.data().somethingElse, undefined);

      // update
      const val2 = await firestore.runTransaction(updateFunction);
      should.equal(val2, 2);
      const doc2 = await docRef.get();
      doc2.data().value.should.equal(2);
      doc2.data().somethingElse.should.equal('update');

      // rejecting / cancelling transaction
      let didReject = false;
      try {
        await firestore.runTransaction(updateFunction);
      } catch (e) {
        didReject = true;
      }
      should.equal(didReject, true);
      const doc3 = await docRef.get();
      doc3.data().value.should.equal(2);
      doc3.data().somethingElse.should.equal('update');

      // delete
      deleteMe = true;
      const val4 = await firestore.runTransaction(updateFunction);
      should.equal(val4, 'bye');
      const doc4 = await docRef.get();
      should.equal(doc4.exists, false);

      return Promise.resolve('Test Completed');
    });
  });
});