ChangesTest.ts

import * as mocha from 'mocha'
import * as sinon from 'sinon'
import * as admin from 'firebase-admin'
import * as changes from '../changes'
import { expect } from 'chai'
import { Event } from 'firebase-functions';
import { DeltaSnapshot } from 'firebase-functions/lib/providers/database';

describe("Change", () => {
    
    let refStub = sinon.stub().returns({ 
        root: { 
            child: sinon.stub().returns({
                push: sinon.stub().returns({ 
                    set: sinon.stub() 
                })
            })
        }
    });

    function createEvent(data, diff) {

        let event: Event<DeltaSnapshot> | UndocumentedEvent = {
            data: new DeltaSnapshot(null, null, data, diff, null),
            auth: {  
                variable: {
                    uid: "123"
                }
            },
            params: {
                entityId: "entity",
                groupId: "group"
            }
        } as Event<DeltaSnapshot>;

        Object.defineProperty(event.data, 'adminRef', { get: refStub });
        Object.defineProperty(event.data, 'ref', { get: refStub });

        return event;
    }

    function createChange(action: string, entity: string) : Change {
        return {
           action: action,
           by: "123",
           entity: entity,
           entityId: "entity"
        };
    }

    it("should be correctly generated for new expense", async () => {

        let tx: Transaction = {
            currencyCode: 'USD',
            purpose: "test tx",
            exchangeRates: {
                "USD": "1.0"
            },
            type: "expense"
        };

        let event = createEvent(null, tx);
        let change = await changes.writeTransactionChange(event);
        let expected = createChange(changes.ACTION_INSERT, changes.ENTITY_EXPENSE);

        expect(change).to.eql(expected);
    })
})