Merge branch 'feature/no-shared-builder' into develop

Author: helje5

Sources/ManagedModels/SchemaCompatibility/NSManagedObjectModel+Data.swift

@@ -23,7 +23,7 @@ public extension NSManagedObjectModel {
                    version: Schema.Version = Version(1, 0, 0))
   {
     self.init()
-    self.entities = SchemaBuilder.shared.lookupAllEntities(for: types)
+    self.entities = SchemaBuilder().lookupAllEntities(for: types)
   }
 
   @inlinable
@@ -38,6 +38,7 @@ public extension NSManagedObjectModel {
 
 private let lock = NSLock()
 private var map = [ Set<ObjectIdentifier> : NSManagedObjectModel ]()
+private let sharedBuilder = SchemaBuilder()
 
 public extension NSManagedObjectModel {
 
@@ -69,7 +70,7 @@ public extension NSManagedObjectModel {
     if let cachedMOM { mom = cachedMOM }
     else {
       mom = NSManagedObjectModel()
-      mom.entities = SchemaBuilder.shared.lookupAllEntities(for: types)
+      mom.entities = sharedBuilder.lookupAllEntities(for: types)
       map[typeIDs] = mom
     }
     lock.unlock()

Sources/ManagedModels/SchemaGeneration/SchemaBuilder.swift

@@ -27,17 +27,11 @@ import CoreData
  */
 public final class SchemaBuilder {
   // Notes:
-  // - this MUST NOT call `.entity` on the model! might recurse w/ lock, this
+  // - this MUST NOT call `.entity()` on the model! might recurse w/ lock, this
   //   object is the authority!
   // - there can be multiple entities that use the same name, this spans the
   //   whole type system. E.g. when versioned schemas are used.
-  
-  /**
-   * A shared SchemaBuilder that caches `NSEntityDescription` values for
-   * ``PersistentModel`` `NSManagedObject`'s.
-   */
-  public static let shared = SchemaBuilder()
-  
+    
   private let lock = NSLock() // TODO: use better lock :-)
 
   /// ObjectIdentifier of PersistentModel type to the associated schema.

Tests/ManagedModelTests/SchemaGenerationTests.swift

@@ -224,7 +224,34 @@ final class SchemaGenerationTests: XCTestCase {
       XCTAssertEqual(address.attributes.count, 2)
     }
   }
-  
+
+  func testDuplicateMOMGeneration() throws {
+    try autoreleasepool {
+      let model1 = NSManagedObjectModel([
+        Fixtures.PersonAddressSchema.Person.self
+      ])
+      XCTAssertEqual(model1.entities.count, 2)
+      
+      let address = try XCTUnwrap(
+        model1.entities.first(where: { $0.name == "Address" })
+      )
+      XCTAssertEqual(address.attributes.count, 2)
+    }
+
+    // second run
+    try autoreleasepool {
+      let model2 = NSManagedObjectModel([
+        Fixtures.PersonAddressSchema.Person.self
+      ])
+      XCTAssertEqual(model2.entities.count, 2)
+      
+      let address = try XCTUnwrap(
+        model2.entities.first(where: { $0.name == "Address" })
+      )
+      XCTAssertEqual(address.attributes.count, 2)
+    }
+  }
+
   func testOptionalBackRef() throws {
     let cache  = SchemaBuilder()
     let schema = NSManagedObjectModel(