test(packages/registry): add tests for SocketRegistry class

- Add 6 tests for empty SocketRegistry class stub
- Test class instantiation and constructor
- Test instanceof checks and prototype chain
- Test independent instance creation
- Handle minified class names in production builds
- Code coverage: 76.03% → 76.04% (+0.01pp)
- Cumulative coverage: 86.37% (maintained)

Author: jdalton

test/packages/registry.test.ts

@@ -0,0 +1,45 @@
+/**
+ * @fileoverview Unit tests for Socket Registry class.
+ */
+
+import { describe, expect, it } from 'vitest'
+
+import { SocketRegistry } from '@socketsecurity/lib/packages/registry'
+
+describe('packages/registry', () => {
+  describe('SocketRegistry', () => {
+    it('should export SocketRegistry class', () => {
+      expect(typeof SocketRegistry).toBe('function')
+    })
+
+    it('should be instantiable', () => {
+      const registry = new SocketRegistry()
+      expect(registry).toBeInstanceOf(SocketRegistry)
+    })
+
+    it('should be a class constructor', () => {
+      expect(SocketRegistry.prototype).toBeDefined()
+      expect(SocketRegistry.prototype.constructor).toBe(SocketRegistry)
+    })
+
+    it('should have a name property', () => {
+      // Note: class name may be minified in production builds
+      expect(typeof SocketRegistry.name).toBe('string')
+      expect(SocketRegistry.name.length).toBeGreaterThan(0)
+    })
+
+    it('should create independent instances', () => {
+      const registry1 = new SocketRegistry()
+      const registry2 = new SocketRegistry()
+      expect(registry1).not.toBe(registry2)
+      expect(registry1).toBeInstanceOf(SocketRegistry)
+      expect(registry2).toBeInstanceOf(SocketRegistry)
+    })
+
+    it('should support instanceof checks', () => {
+      const registry = new SocketRegistry()
+      expect(registry instanceof SocketRegistry).toBe(true)
+      expect(registry instanceof Object).toBe(true)
+    })
+  })
+})