Repository: typeorm/typeorm
File: test/github-issues/9944/issue-9944.ts (TypeScript)

Code before:
import "reflect-metadata"
import {
    createTestingConnections,
    closeTestingConnections,
    reloadTestingDatabases,
} from "../../utils/test-utils"
import { DataSource } from "../../../src/data-source/DataSource"
import { expect } from "chai"
import { A } from "./entity/A"
import { B } from "./entity/B"
import { C } from "./entity/C"

describe("github issues > #9944 Alias Issue With Nested Entity And Relations", () => {
    let dataSources: DataSource[]
    before(
        async () =>
            (dataSources = await createTestingConnections({
                entities: [__dirname + "/entity/*{.js,.ts}"],
                schemaCreate: true,
                dropSchema: true,
                relationLoadStrategy: "query",
                enabledDrivers: ["mysql"],
            })),
    )
    beforeEach(() => reloadTestingDatabases(dataSources))
    after(() => closeTestingConnections(dataSources))

    it("Validate correct loading of eager, nested relations", () =>
        Promise.all(
            dataSources.map(async (dataSource) => {
                const aEntity = new A()
                aEntity.b = new B()
                aEntity.b.cs = [new C()]
                await dataSource.manager.save(aEntity)

                const [fetchedA] = await dataSource.manager.find(A)
                expect(fetchedA.b).exist // Validates correct relation A.b is loaded
                expect(fetchedA.b.cs).exist // Validates correct relation A.b.cs is loaded
                expect(fetchedA.b.cs[0]).exist
            }),
        ))
})


Review comment (suggestion):
Maybe, this could also be a problem for `postgres` not only `mysql`. 😊 

Code after:
import "reflect-metadata"
import {
    createTestingConnections,
    closeTestingConnections,
    reloadTestingDatabases,
} from "../../utils/test-utils"
import { DataSource } from "../../../src/data-source/DataSource"
import { expect } from "chai"
import { A } from "./entity/A"
import { B } from "./entity/B"
import { C } from "./entity/C"

describe("github issues > #9944 Alias Issue With Nested Entity And Relations", () => {
    let dataSources: DataSource[]
    before(
        async () =>
            (dataSources = await createTestingConnections({
                entities: [__dirname + "/entity/*{.js,.ts}"],
                schemaCreate: true,
                dropSchema: true,
                relationLoadStrategy: "query",
                enabledDrivers: ["mysql", "postgres"],
            })),
    )
    beforeEach(() => reloadTestingDatabases(dataSources))
    after(() => closeTestingConnections(dataSources))

    it("Validate correct loading of eager, nested relations", () =>
        Promise.all(
            dataSources.map(async (dataSource) => {
                const aEntity = new A()
                aEntity.b = new B()
                aEntity.b.cs = [new C()]
                await dataSource.manager.save(aEntity)

                const [fetchedA] = await dataSource.manager.find(A)
                expect(fetchedA.b).exist // Validates correct relation A.b is loaded
                expect(fetchedA.b.cs).exist // Validates correct relation A.b.cs is loaded
                expect(fetchedA.b.cs[0]).exist
            }),
        ))
})