An extension on XCTestCase to setup an in-memory persistent store coordinator

XCTestCase+CoreDataHelper.swift

import Foundation
import XCTest
import CoreData

@testable import MainModule

extension XCTestCase {
    func setUpInMemoryManagedObjectContext() -> NSManagedObjectContext {
        let managedObjectModel = NSManagedObjectModel.mergedModel(from: [Bundle.main])!
        
        let persistentStoreCoordinator = NSPersistentStoreCoordinator(managedObjectModel: managedObjectModel)
        
        do {
            try persistentStoreCoordinator.addPersistentStore(ofType: NSInMemoryStoreType, configurationName: nil, at: nil, options: nil)
        } catch {
            print("Adding in-memory persistent store failed")
        }
        
        let managedObjectContext = NSManagedObjectContext(concurrencyType:.privateQueueConcurrencyType)
        managedObjectContext.persistentStoreCoordinator = persistentStoreCoordinator
        
        return managedObjectContext
    }
}