feat(datastore): add subscription variables for multi-tenant filtering

packages/datastore/__tests__/subscription-variables-edge-cases.test.ts

@@ -0,0 +1,239 @@
+import { SubscriptionProcessor } from '../src/sync/processors/subscription';
+import { TransformerMutationType, processSubscriptionVariables } from '../src/sync/utils';
+import { SchemaModel, InternalSchema } from '../src/types';
+
+describe('Subscription Variables - Edge Cases & Safety', () => {
+	let mockGraphQL: jest.Mock;
+
+	beforeEach(() => {
+		mockGraphQL = jest.fn();
+		jest.clearAllMocks();
+	});
+
+	const createTestSchema = (): InternalSchema => ({
+		namespaces: {
+			user: {
+				name: 'user',
+				models: {
+					Todo: {
+						name: 'Todo',
+						pluralName: 'Todos',
+						syncable: true,
+						attributes: [],
+						fields: {
+							id: {
+								name: 'id',
+								type: 'ID',
+								isRequired: true,
+								isArray: false,
+							},
+						},
+					},
+				},
+				relationships: {},
+				enums: {},
+				nonModels: {},
+			},
+		},
+		version: '1',
+		codegenVersion: '3.0.0',
+	});
+
+	describe('Mutation Protection', () => {
+		it('should not allow mutations to affect cached values', () => {
+			const schema = createTestSchema();
+			const sharedObject = { storeId: 'initial' };
+
+			const cache = new WeakMap();
+			const result1 = processSubscriptionVariables(
+				schema.namespaces.user.models.Todo,
+				TransformerMutationType.CREATE,
+				sharedObject,
+				cache,
+			);
+
+			sharedObject.storeId = 'mutated';
+
+			const result2 = processSubscriptionVariables(
+				schema.namespaces.user.models.Todo,
+				TransformerMutationType.CREATE,
+				sharedObject,
+				cache,
+			);
+
+			expect(result1).toEqual(result2);
+			expect(result2?.storeId).not.toBe('mutated');
+		});
+
+		it('should handle circular references gracefully', () => {
+			const schema = createTestSchema();
+			const circular: any = { storeId: 'test' };
+			circular.self = circular;
+
+			const cache = new WeakMap();
+			const result = processSubscriptionVariables(
+				schema.namespaces.user.models.Todo,
+				TransformerMutationType.CREATE,
+				circular,
+				cache,
+			);
+
+			expect(result).toBeDefined();
+			expect(result?.storeId).toBe('test');
+		});
+	});
+
+	describe('Invalid Input Handling', () => {
+		it('should reject non-object static variables', () => {
+			const schema = createTestSchema();
+
+			const testCases = [
+				{ value: 'string', desc: 'string' },
+				{ value: 123, desc: 'number' },
+				{ value: true, desc: 'boolean' },
+				{ value: ['array'], desc: 'array' },
+			];
+
+			testCases.forEach(({ value, desc }) => {
+				const cache = new WeakMap();
+				const result = processSubscriptionVariables(
+					schema.namespaces.user.models.Todo,
+					TransformerMutationType.CREATE,
+					value as any,
+					cache,
+				);
+
+				expect(result).toBeUndefined();
+			});
+		});
+
+		it('should handle Object.create(null) objects', () => {
+			const schema = createTestSchema();
+			const nullProtoObj = Object.create(null);
+			nullProtoObj.storeId = 'test';
+
+			const cache = new WeakMap();
+			const result = processSubscriptionVariables(
+				schema.namespaces.user.models.Todo,
+				TransformerMutationType.CREATE,
+				nullProtoObj,
+				cache,
+			);
+
+			expect(result).toBeDefined();
+			expect(result?.storeId).toBe('test');
+		});
+
+		it('should handle function that throws', () => {
+			const schema = createTestSchema();
+
+			const cache = new WeakMap();
+			const mockFn = () => {
+				throw new Error('Function error');
+			};
+			const result = processSubscriptionVariables(
+				schema.namespaces.user.models.Todo,
+				TransformerMutationType.CREATE,
+				mockFn,
+				cache,
+			);
+
+			expect(result).toBeUndefined();
+		});
+
+		it('should handle function returning non-object', () => {
+			const schema = createTestSchema();
+
+			const testCases = [
+				{ value: null, desc: 'null' },
+				{ value: undefined, desc: 'undefined' },
+				{ value: 'string', desc: 'string' },
+				{ value: 123, desc: 'number' },
+				{ value: ['array'], desc: 'array' },
+			];
+
+			testCases.forEach(({ value, desc }) => {
+				const cache = new WeakMap();
+				const mockFn = () => value;
+				const result = processSubscriptionVariables(
+					schema.namespaces.user.models.Todo,
+					TransformerMutationType.CREATE,
+					mockFn as any,
+					cache,
+				);
+
+				expect(result).toBeUndefined();
+			});
+		});
+	});
+
+	describe('Cache Behavior', () => {
+		it('should only call function once per operation', () => {
+			const schema = createTestSchema();
+			const mockFn = jest.fn(() => ({ storeId: 'test' }));
+
+			const cache = new WeakMap();
+			for (let i = 0; i < 5; i++) {
+				processSubscriptionVariables(
+					schema.namespaces.user.models.Todo,
+					TransformerMutationType.CREATE,
+					mockFn,
+					cache,
+				);
+			}
+
+			expect(mockFn).toHaveBeenCalledTimes(1);
+			expect(mockFn).toHaveBeenCalledWith(TransformerMutationType.CREATE);
+
+			processSubscriptionVariables(
+				schema.namespaces.user.models.Todo,
+				TransformerMutationType.UPDATE,
+				mockFn,
+				cache,
+			);
+
+			expect(mockFn).toHaveBeenCalledTimes(2);
+			expect(mockFn).toHaveBeenCalledWith(TransformerMutationType.UPDATE);
+		});
+
+		it('should clear cache on stop', async () => {
+			const schema = createTestSchema();
+			const mockFn = jest.fn(() => ({ storeId: 'test' }));
+
+			const processor = new SubscriptionProcessor(
+				schema,
+				new WeakMap(),
+				{},
+				'DEFAULT' as any,
+				jest.fn(),
+				{ InternalAPI: { graphql: mockGraphQL } } as any,
+				{
+					subscriptionVariables: {
+						Todo: mockFn,
+					},
+				},
+			);
+
+			let cache = new WeakMap();
+			processSubscriptionVariables(
+				schema.namespaces.user.models.Todo,
+				TransformerMutationType.CREATE,
+				mockFn,
+				cache,
+			);
+			expect(mockFn).toHaveBeenCalledTimes(1);
+
+			await processor.stop();
+			cache = new WeakMap();
+
+			processSubscriptionVariables(
+				schema.namespaces.user.models.Todo,
+				TransformerMutationType.CREATE,
+				mockFn,
+				cache,
+			);
+
+			expect(mockFn).toHaveBeenCalledTimes(2);
+		});
+	});
+});