Updated unit tests

Sources/CoreModel/InMemoryStore.swift

@@ -23,7 +23,36 @@ public final class InMemoryStore: StoreProtocol {
     /// Fetch managed objects.
     public func fetch(_ fetchRequest: FetchRequest) throws -> [ManagedObject] {
 
-        fatalError()
+        var identifiers = data.keys.filter { $0.entity == fetchRequest.entity }
+
+        if fetchRequest.fetchOffset > 0 {
+
+            identifiers = Array(identifiers.suffix(fetchRequest.fetchOffset))
+        }
+
+        if fetchRequest.fetchLimit > 0 {
+
+            identifiers = Array(identifiers.prefix(fetchRequest.fetchLimit))
+        }
+
+        var managedObjects = identifiers.map { ManagedObject(identifier: $0, store: self) }
+
+        if let predicate = fetchRequest.predicate {
+
+            managedObjects = try managedObjects.filter {
+                try $0.evaluate(with: predicate)
+            }
+        }
+
+        if fetchRequest.sortDescriptors.isEmpty == false {
+
+            for sort in fetchRequest.sortDescriptors.reversed() {
+
+                //managedObjects.sort(by: { $0. })
+            }
+        }
+
+        return managedObjects
     }
 
     /// Create new managed object.
@@ -275,3 +304,11 @@ private extension InMemoryStore {
         case toMany(Set<Identifier>)
     }
 }
+
+extension InMemoryStore.ManagedObject: PredicateEvaluatable {
+
+    public func evaluate(with predicate: Predicate) throws -> Bool {
+
+
+    }
+}

Tests/CoreModelTests/CoreModelTests.swift

@@ -103,6 +103,9 @@ final class CoreModelTests: XCTestCase {
             XCTAssertFalse(person2.isDeleted)
             XCTAssertEqual(person1.relationship(for: "events"), .toMany([]))
             XCTAssertEqual(person2.relationship(for: "events"), .toMany([]))
+
+            XCTAssertEqual(try store.fetch(FetchRequest(entity: "Person")), [person1, person2])
+            XCTAssertEqual(try store.fetch(FetchRequest(entity: "Event")), [event])
         }
 
         catch { XCTFail("\(error)") }