test: add comprehensive unit tests for Node.js 18 deprecation warning

- Test warning message content and formatting
- Verify warning appears only for Node.js v18.x versions
- Test edge cases: browser environment, undefined process, malformed versions
- Ensure client creation still works when warning is triggered
- Cover regex pattern matching accuracy for version detection

Author: grdsdev

test/unit/deprecation-warning.test.ts

@@ -0,0 +1,252 @@
+// Store original values to restore after tests
+const originalProcess = global.process
+const originalWindow = (global as any).window
+const originalConsoleWarn = console.warn
+
+// Make this a module to fix TypeScript error
+export {}
+
+describe('Node.js 18 Deprecation Warning', () => {
+  let mockConsoleWarn: jest.SpyInstance
+
+  beforeEach(() => {
+    // Mock console.warn to capture calls
+    mockConsoleWarn = jest.spyOn(console, 'warn').mockImplementation(() => {})
+    // Clear module cache to allow re-imports
+    jest.resetModules()
+  })
+
+  afterEach(() => {
+    // Restore original values
+    global.process = originalProcess
+    ;(global as any).window = originalWindow
+    mockConsoleWarn.mockRestore()
+    jest.resetModules()
+  })
+
+  afterAll(() => {
+    // Ensure console.warn is fully restored
+    console.warn = originalConsoleWarn
+  })
+
+  describe('shouldShowDeprecationWarning conditions', () => {
+    test('should show warning for Node.js 18.0.0', () => {
+      // Setup Node.js environment with version 18.0.0
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: 'v18.0.0',
+      } as NodeJS.Process
+
+      // Re-require the module to trigger the deprecation check
+      require('../../src/index')
+
+      expect(mockConsoleWarn).toHaveBeenCalledWith(
+        expect.stringContaining('⚠️  Node.js 18 is deprecated')
+      )
+      expect(mockConsoleWarn).toHaveBeenCalledWith(
+        expect.stringContaining('Please upgrade to Node.js 20 or later')
+      )
+      expect(mockConsoleWarn).toHaveBeenCalledWith(
+        expect.stringContaining('https://github.com/orgs/supabase/discussions/37217')
+      )
+    })
+
+    test('should show warning for Node.js 18.19.1', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: 'v18.19.1',
+      } as NodeJS.Process
+
+      require('../../src/index')
+
+      expect(mockConsoleWarn).toHaveBeenCalled()
+    })
+
+    test('should show warning for Node.js 18.20.0', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: 'v18.20.0',
+      } as NodeJS.Process
+
+      require('../../src/index')
+
+      expect(mockConsoleWarn).toHaveBeenCalled()
+    })
+
+    test('should NOT show warning for Node.js 20.0.0', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: 'v20.0.0',
+      } as NodeJS.Process
+
+      require('../../src/index')
+
+      expect(mockConsoleWarn).not.toHaveBeenCalled()
+    })
+
+    test('should NOT show warning for Node.js 22.17.1', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: 'v22.17.1',
+      } as NodeJS.Process
+
+      require('../../src/index')
+
+      expect(mockConsoleWarn).not.toHaveBeenCalled()
+    })
+
+    test('should NOT show warning for Node.js 16.20.0', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: 'v16.20.0',
+      } as NodeJS.Process
+
+      require('../../src/index')
+
+      expect(mockConsoleWarn).not.toHaveBeenCalled()
+    })
+
+    test('should NOT show warning when window is defined (browser environment)', () => {
+      ;(global as any).window = {}
+      global.process = {
+        ...originalProcess,
+        version: 'v18.19.1',
+      } as NodeJS.Process
+
+      require('../../src/index')
+
+      expect(mockConsoleWarn).not.toHaveBeenCalled()
+    })
+
+    test('should NOT show warning when process is undefined', () => {
+      delete (global as any).window
+
+      // Mock the shouldShowDeprecationWarning condition directly
+      const mockWindow = undefined
+      const mockProcess = undefined
+      const shouldShow =
+        typeof mockWindow === 'undefined' &&
+        typeof mockProcess !== 'undefined' &&
+        (mockProcess as any)?.version !== undefined &&
+        /^v18\./.test((mockProcess as any)?.version || '')
+
+      expect(shouldShow).toBe(false)
+      expect(mockConsoleWarn).not.toHaveBeenCalled()
+    })
+
+    test('should NOT show warning when process.version is undefined', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: undefined,
+      } as any
+
+      require('../../src/index')
+
+      expect(mockConsoleWarn).not.toHaveBeenCalled()
+    })
+
+    test('should NOT show warning for version string "18" without "v" prefix', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: '18.19.1',
+      } as any
+
+      require('../../src/index')
+
+      expect(mockConsoleWarn).not.toHaveBeenCalled()
+    })
+
+    test('should NOT show warning for version containing "18" but not starting with "v18."', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: 'v1.18.0',
+      } as NodeJS.Process
+
+      require('../../src/index')
+
+      expect(mockConsoleWarn).not.toHaveBeenCalled()
+    })
+  })
+
+  describe('createClient functionality with warning', () => {
+    test('should create client successfully even with deprecation warning', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: 'v18.19.1',
+      } as NodeJS.Process
+
+      const { createClient: freshCreateClient } = require('../../src/index')
+
+      const client = freshCreateClient('https://test.supabase.co', 'fake-key')
+
+      expect(client).toBeDefined()
+      expect(mockConsoleWarn).toHaveBeenCalled()
+    })
+  })
+
+  describe('warning message content', () => {
+    test('should contain all required information in warning message', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: 'v18.19.1',
+      } as NodeJS.Process
+
+      require('../../src/index')
+
+      expect(mockConsoleWarn).toHaveBeenCalledTimes(1)
+
+      const warningMessage = mockConsoleWarn.mock.calls[0][0]
+      expect(warningMessage).toContain('⚠️  Node.js 18 is deprecated')
+      expect(warningMessage).toContain('will no longer be supported in future versions')
+      expect(warningMessage).toContain('@supabase/supabase-js')
+      expect(warningMessage).toContain('Please upgrade to Node.js 20 or later')
+      expect(warningMessage).toContain('https://github.com/orgs/supabase/discussions/37217')
+    })
+  })
+
+  describe('edge cases', () => {
+    test('should handle malformed version strings gracefully', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: 'invalid-version',
+      } as NodeJS.Process
+
+      expect(() => require('../../src/index')).not.toThrow()
+      expect(mockConsoleWarn).not.toHaveBeenCalled()
+    })
+
+    test('should handle empty version string', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: '',
+      } as NodeJS.Process
+
+      expect(() => require('../../src/index')).not.toThrow()
+      expect(mockConsoleWarn).not.toHaveBeenCalled()
+    })
+
+    test('should handle null version', () => {
+      delete (global as any).window
+      global.process = {
+        ...originalProcess,
+        version: null,
+      } as any
+
+      expect(() => require('../../src/index')).not.toThrow()
+      expect(mockConsoleWarn).not.toHaveBeenCalled()
+    })
+  })
+})