fix: avoid Next.js Edge Runtime warnings in Node.js deprecation check (#1520)

* fix: avoid Next.js Edge Runtime warnings in Node.js deprecation check

Use dynamic property access for process.version to prevent Next.js static
analysis from flagging the code as incompatible with Edge Runtime.

The deprecation warning logic remains unchanged - it only runs in actual
Node.js environments and is properly guarded against Edge Runtime execution.

Fixes #1515

* fix: restore undefined and null checks for process.version

Maintain the original defensive programming checks while still using
dynamic property access to avoid Edge Runtime warnings

* test: add comprehensive tests for Node.js deprecation warning

- Test browser environment detection
- Test Edge Runtime compatibility (no process object)
- Test various process.version states (undefined, null, invalid)
- Test version detection for Node.js 16, 18, 20, 22
- Test invalid version format handling

* fix: update deprecation tests to work with TypeScript isolatedModules

- Add export {} to make file a module
- Remove problematic test for undefined process (dependencies require it)
- Add comment explaining why Edge Runtime scenario is hard to test in Node

* test: eliminate TTYWRAP warnings in deprecation tests

Use Object.defineProperty to mock only process.version instead of
spreading the entire process object. This avoids copying TTY handles
and other complex properties that cause Jest warnings.

Author: mandarini

src/index.ts

@@ -42,16 +42,23 @@ export const createClient = <
 
 // Check for Node.js <= 18 deprecation
 function shouldShowDeprecationWarning(): boolean {
-  if (
-    typeof window !== 'undefined' ||
-    typeof process === 'undefined' ||
-    process.version === undefined ||
-    process.version === null
-  ) {
+  // Skip in browser environments
+  if (typeof window !== 'undefined') {
     return false
   }
 
-  const versionMatch = process.version.match(/^v(\d+)\./)
+  // Skip if process is not available (e.g., Edge Runtime)
+  if (typeof process === 'undefined') {
+    return false
+  }
+
+  // Use dynamic property access to avoid Next.js Edge Runtime static analysis warnings
+  const processVersion = (process as any)['version']
+  if (processVersion === undefined || processVersion === null) {
+    return false
+  }
+
+  const versionMatch = processVersion.match(/^v(\d+)\./)
   if (!versionMatch) {
     return false
   }

test/unit/deprecation.test.ts

@@ -0,0 +1,143 @@
+/**
+ * @jest-environment node
+ */
+
+// Make this file a module to satisfy TypeScript's isolatedModules
+export {}
+
+describe('Node.js deprecation warning', () => {
+  const originalProcess = global.process
+  const originalWindow = global.window
+  const originalConsoleWarn = console.warn
+
+  beforeEach(() => {
+    // Reset modules to re-run the deprecation check
+    jest.resetModules()
+    // Mock console.warn
+    console.warn = jest.fn()
+  })
+
+  afterEach(() => {
+    // Restore original values
+    global.process = originalProcess
+    global.window = originalWindow
+    console.warn = originalConsoleWarn
+    jest.resetModules()
+  })
+
+  it('should not show warning in browser environment', () => {
+    // Simulate browser environment
+    global.window = {} as any
+
+    require('../../src/index')
+
+    expect(console.warn).not.toHaveBeenCalled()
+  })
+
+  // Note: We can't easily test "process is undefined" because dependencies like ws require it
+  // The code handles it correctly with typeof process === 'undefined' check
+  // In real Edge Runtime, the module loading context is different
+
+  it('should not show warning when process.version is undefined', () => {
+    // Process exists but version is undefined
+    // Only mock the version property to avoid TTYWRAP warnings
+    Object.defineProperty(global.process, 'version', {
+      value: undefined,
+      configurable: true,
+    })
+
+    require('../../src/index')
+
+    expect(console.warn).not.toHaveBeenCalled()
+  })
+
+  it('should not show warning when process.version is null', () => {
+    // Process exists but version is null
+    // Only mock the version property to avoid TTYWRAP warnings
+    Object.defineProperty(global.process, 'version', {
+      value: null,
+      configurable: true,
+    })
+
+    require('../../src/index')
+
+    expect(console.warn).not.toHaveBeenCalled()
+  })
+
+  it('should show warning for Node.js 18', () => {
+    Object.defineProperty(global.process, 'version', {
+      value: 'v18.0.0',
+      configurable: true,
+    })
+    delete (global as any).window
+
+    require('../../src/index')
+
+    expect(console.warn).toHaveBeenCalledWith(
+      expect.stringContaining('Node.js 18 and below are deprecated')
+    )
+  })
+
+  it('should show warning for Node.js 16', () => {
+    Object.defineProperty(global.process, 'version', {
+      value: 'v16.14.0',
+      configurable: true,
+    })
+    delete (global as any).window
+
+    require('../../src/index')
+
+    expect(console.warn).toHaveBeenCalledWith(
+      expect.stringContaining('Node.js 18 and below are deprecated')
+    )
+  })
+
+  it('should not show warning for Node.js 20', () => {
+    Object.defineProperty(global.process, 'version', {
+      value: 'v20.0.0',
+      configurable: true,
+    })
+    delete (global as any).window
+
+    require('../../src/index')
+
+    expect(console.warn).not.toHaveBeenCalled()
+  })
+
+  it('should not show warning for Node.js 22', () => {
+    Object.defineProperty(global.process, 'version', {
+      value: 'v22.0.0',
+      configurable: true,
+    })
+    delete (global as any).window
+
+    require('../../src/index')
+
+    expect(console.warn).not.toHaveBeenCalled()
+  })
+
+  it('should handle invalid version format gracefully', () => {
+    Object.defineProperty(global.process, 'version', {
+      value: 'invalid-version',
+      configurable: true,
+    })
+    delete (global as any).window
+
+    require('../../src/index')
+
+    expect(console.warn).not.toHaveBeenCalled()
+  })
+
+  it('should handle version without v prefix', () => {
+    Object.defineProperty(global.process, 'version', {
+      value: '18.0.0',
+      configurable: true,
+    })
+    delete (global as any).window
+
+    require('../../src/index')
+
+    // Should not match the regex and thus not show warning
+    expect(console.warn).not.toHaveBeenCalled()
+  })
+})