Testing a MySQL INSERT result with Node.js/Sinon - mysql

Question

My application code to test:
create(params) {
let result = {};
try {
result = await this.db.query('/* some query */');
} catch (e) {
throw new Error('Error creating User', e);
}
return this._getById(result.insertId);
}
I have the _getById method in the same class which does exactly what it says...
And my current test (running through Ava):
test('it should create a user', async t => {
const db = mock({
query: () => {
},
});
const userObj = {
// some params
};
const user = new Users({
db: db.object,
});
const call = {
request: userObj,
};
const result = await user.create(call);
// test?
});
If I try and test anything based off of the result variable, ie. the newly created User, I receive the error "Cannot read property 'insertId' of undefined". What is my best option with Sinon to test that this create method will return a newly created "user"?

Answer 1

I think that you have the "Cannot read property 'insertId' of undefined" because the following mock doesn't return something
const db = mock({
query: () => {
},
});
If you return something like that
const db = mock({
query: () => {
return {
username: "username"
}
},
});
and in the test the result will have the value and you should be able to use expect to check if you have the expected result:
{
username: "username"
}
The problem in this specific test starts when the mock does not return something and also calling mock overrode the value that you assigned here
let result = {};