Mocha tests can't connect to postgres database, using knex - postgresql

Question

I am trying to implement some integration tests using mocha for functions that interact with a postgres database through knex, in a nodejs express app.
The functions work outside of mocha - I can start the app in node or nodemon, submit requests through Postman, retrieve records from the database, add new records, etc. But when I try to test the code through mocha, I get errors like the following for any functions that try to access the database:
select * from "item" where "user_id" = $1 - relation "item" does not exist
The environment variable for the database connection is set to connect to the right database; when I manually test the app end-to-end, everything works; I get data back from the database.
I've included what I think are the relevant code snippets below: the test script for one of the tests that won't work, the function I'm trying to test, and the modules that that function relies on.
TEST SCRIPT
const Item = require('../db/item');
const chai = require('chai');
const chaiAsPromised = require('chai-as-promised');
// set up the middleware
chai.use(chaiAsPromised);
var should = require('chai').should()
describe('Item.getByUser', function() {
contex`enter code here`t('With valid id', function() {
const item_id = 1;
const expectedResult = "Canoe";
it('should return items', function() {
return Item
.getByUser(item_id)
.then(items => {
items[0].name.should.equal(expectedResult);
});
});
});
SNIPPET FROM THE ITEM.GETBYUSER FUNCTION:
const knex = require('./connection');
module.exports = {
getByUser: function(id) {
return knex('item').where('user_id', id);
},
SNIPPET FROM THE CONNECTION MODULE:
require('dotenv-safe').config();
const environment = process.env.NODE_ENV || 'development';
const config = require('../knexfile')[environment];
module.exports = require('knex')(config);
SNIPPET FROM THE KNEXFILE MODULE:
module.exports = {
development: {
client: 'pg',
connection: process.env.DATABASE_URL
},
production: {
client: 'pg',
connection: process.env.DATABASE_URL
}
};
The error message I get for the above test is:
1) Item.getByUser
With valid id
should return items:
select * from "item" where "user_id" = $1 - relation "item" does not exist
error: relation "item" does not exist
at Connection.parseE (node_modules\pg\lib\connection.js:567:11)
at Connection.parseMessage (node_modules\pg\lib\connection.js:391:17)
at Socket.<anonymous> (node_modules\pg\lib\connection.js:129:22)
at addChunk (_stream_readable.js:284:12)
at readableAddChunk (_stream_readable.js:265:11)
at Socket.Readable.push (_stream_readable.js:220:10)
at TCP.onStreamRead [as onread] (internal/stream_base_commons.js:94:17)

Answer 1

Okay, it's looking like this was in fact related to the environment variable for the database in some way I can't quite figure out. Although I had the database connection set to 'postgres://localhost/mydatabase' the database actually being used when I tested the db live, including migrating and seeding the database through knex commands, was 'postgres://localhost/username' - a database with the same name as the Owner of 'mydatabase'. But I think the mocha tests were trying to connect to mydatabase, which was still empty at that point, since the migrate and seed affected the the database 'username.'
So, I think this can be closed. I'll try to replicate the problem where I was connected to the wrong db; not sure how that could have happened, as I never intentionally set the connection, or any environment variable to 'postgres://localhost/username'.