feat: implement environment utilities tests for Node compatibility

Author: hotlong

packages/core/src/logger.ts

@@ -1,5 +1,6 @@
 import type { LoggerConfig, LogLevel } from '@objectstack/spec/system';
 import type { Logger } from '@objectstack/spec/contracts';
+import { isNode } from './utils/env.js';
 
 /**
  * Universal Logger Implementation
@@ -25,7 +26,7 @@ export class ObjectLogger implements Logger {
 
     constructor(config: Partial<LoggerConfig> = {}) {
         // Detect runtime environment
-        this.isNode = typeof process !== 'undefined' && process.versions?.node !== undefined;
+        this.isNode = isNode;
 
         // Set defaults
         this.config = {

packages/core/src/utils/env.test.ts

@@ -0,0 +1,62 @@
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import * as envUtils from './env';
+
+describe('Environment Utilities', () => {
+    
+    // Save original process
+    const originalProcess = globalThis.process;
+
+    afterEach(() => {
+        // Restore process after each test
+        globalThis.process = originalProcess;
+        vi.restoreAllMocks();
+    });
+
+    describe('isNode', () => {
+        it('should detect Node environment', () => {
+            // Since we are running in Vitest (Node), this should be true
+            expect(envUtils.isNode).toBe(true);
+        });
+    });
+
+    describe('getEnv', () => {
+        it('should retrieve environment variable in Node', () => {
+            process.env.TEST_VAR = 'test_value';
+            expect(envUtils.getEnv('TEST_VAR')).toBe('test_value');
+            delete process.env.TEST_VAR;
+        });
+
+        it('should return default value if variable not found', () => {
+            expect(envUtils.getEnv('NON_EXISTENT_VAR', 'default')).toBe('default');
+        });
+
+        it('should access globalThis.process.env if process is not available directly', () => {
+            // This is tricky to test in Node because 'process' is globally available. 
+            // We can't easily delete global.process in strict mode or without breaking tooling.
+            // But we can verify it works via globalThis
+            
+            // @ts-ignore
+            globalThis.process.env.TEST_GLOBAL_VAR = 'global_value';
+            expect(envUtils.getEnv('TEST_GLOBAL_VAR')).toBe('global_value');
+             // @ts-ignore
+            delete globalThis.process.env.TEST_GLOBAL_VAR;
+        });
+    });
+
+    describe('getMemoryUsage', () => {
+        it('should return memory usage in Node', () => {
+            const usage = envUtils.getMemoryUsage();
+            expect(usage).toHaveProperty('heapUsed');
+            expect(usage).toHaveProperty('heapTotal');
+            expect(usage.heapUsed).toBeGreaterThan(0);
+        });
+    });
+
+    describe('safeExit', () => {
+        it('should call process.exit in Node', () => {
+            const exitSpy = vi.spyOn(process, 'exit').mockImplementation((() => {}) as any);
+            envUtils.safeExit(1);
+            expect(exitSpy).toHaveBeenCalledWith(1);
+        });
+    });
+});