feat: Working on mocks and mock storage.

Sources/DatabaseClient/Vendors.swift

@@ -51,3 +51,94 @@ extension DatabaseClient.Vendors.GetRequest: Content {}
 extension DatabaseClient.Vendors: TestDependencyKey {
   public static let testValue: DatabaseClient.Vendors = Self()
 }
+
+#if DEBUG
+
+  typealias VendorMockStorage = MockStorage<
+    Vendor,
+    Vendor.Create,
+    DatabaseClient.Vendors.FetchRequest,
+    DatabaseClient.Vendors.GetRequest,
+    Vendor.Update
+  >
+
+  private extension VendorMockStorage {
+
+    // swiftlint:disable function_body_length
+    static func vendors(_ mocks: [Vendor]) -> Self {
+      @Dependency(\.date.now) var now
+      @Dependency(\.uuid) var uuid
+      @Dependency(\.database.vendorBranches) var vendorBranches
+
+      return .init(
+        mocks,
+        create: {
+          Vendor(
+            id: uuid(),
+            name: $0.name,
+            createdAt: now,
+            updatedAt: now
+          )
+        },
+        fetch: { _ in
+          { _ in true }
+        },
+        fetchExtras: { request, models in
+          guard request == .withBranches else { return models }
+          let branches = try await vendorBranches.fetchAll()
+          return models.map { model in
+            Vendor(
+              id: model.id,
+              name: model.name,
+              branches: Array(branches.filter { $0.vendorID == model.id }),
+              createdAt: model.createdAt,
+              updatedAt: model.updatedAt
+            )
+          }
+        },
+        get: { req, model in
+          guard req == .withBranches else { return model }
+          let branches = try await vendorBranches.fetchAll(.for(vendorID: model.id))
+          return Vendor(
+            id: model.id,
+            name: model.name,
+            branches: branches,
+            createdAt: model.createdAt,
+            updatedAt: model.updatedAt
+          )
+        },
+        update: { model, updates, get in
+          var branches: [VendorBranch]?
+
+          if get == .withBranches {
+            branches = try await vendorBranches.fetchAll(.for(vendorID: model.id))
+          }
+
+          let vendor = Vendor(
+            id: model.id,
+            name: updates.name ?? model.name,
+            branches: branches ?? model.branches,
+            createdAt: model.createdAt,
+            updatedAt: now
+          )
+          model = vendor
+        }
+      )
+    }
+    // swiftlint:enable function_body_length
+  }
+
+  public extension DatabaseClient.Vendors {
+    static func mock(_ mocks: [Vendor]) -> Self {
+      let storage = VendorMockStorage.vendors(mocks)
+      return .init(
+        create: { try await storage.create($0) },
+        delete: { try await storage.delete($0) },
+        fetchAll: { try await storage.fetchAll($0) },
+        get: { try await storage.get($0, $1) },
+        update: { req, updates, get in try await storage.update(req, updates, get) }
+      )
+    }
+  }
+
+#endif