feat(core): centralize compatibility checks and add TrueColor detection (#19478)

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

@@ -0,0 +1,156 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import os from 'node:os';
+import {
+  isWindows10,
+  isJetBrainsTerminal,
+  supportsTrueColor,
+  getCompatibilityWarnings,
+} from './compatibility.js';
+
+vi.mock('node:os', () => ({
+  default: {
+    platform: vi.fn(),
+    release: vi.fn(),
+  },
+}));
+
+describe('compatibility', () => {
+  const originalGetColorDepth = process.stdout.getColorDepth;
+
+  afterEach(() => {
+    process.stdout.getColorDepth = originalGetColorDepth;
+    vi.restoreAllMocks();
+    vi.unstubAllEnvs();
+  });
+
+  describe('isWindows10', () => {
+    it('should return true for Windows 10 (build < 22000)', () => {
+      vi.mocked(os.platform).mockReturnValue('win32');
+      vi.mocked(os.release).mockReturnValue('10.0.19041');
+      expect(isWindows10()).toBe(true);
+    });
+
+    it('should return false for Windows 11 (build >= 22000)', () => {
+      vi.mocked(os.platform).mockReturnValue('win32');
+      vi.mocked(os.release).mockReturnValue('10.0.22000');
+      expect(isWindows10()).toBe(false);
+    });
+
+    it('should return false for non-Windows platforms', () => {
+      vi.mocked(os.platform).mockReturnValue('darwin');
+      vi.mocked(os.release).mockReturnValue('20.6.0');
+      expect(isWindows10()).toBe(false);
+    });
+  });
+
+  describe('isJetBrainsTerminal', () => {
+    it('should return true when TERMINAL_EMULATOR is JetBrains-JediTerm', () => {
+      vi.stubEnv('TERMINAL_EMULATOR', 'JetBrains-JediTerm');
+      expect(isJetBrainsTerminal()).toBe(true);
+    });
+
+    it('should return false for other terminals', () => {
+      vi.stubEnv('TERMINAL_EMULATOR', 'something-else');
+      expect(isJetBrainsTerminal()).toBe(false);
+    });
+
+    it('should return false when TERMINAL_EMULATOR is not set', () => {
+      vi.stubEnv('TERMINAL_EMULATOR', '');
+      expect(isJetBrainsTerminal()).toBe(false);
+    });
+  });
+
+  describe('supportsTrueColor', () => {
+    it('should return true when COLORTERM is truecolor', () => {
+      vi.stubEnv('COLORTERM', 'truecolor');
+      expect(supportsTrueColor()).toBe(true);
+    });
+
+    it('should return true when COLORTERM is 24bit', () => {
+      vi.stubEnv('COLORTERM', '24bit');
+      expect(supportsTrueColor()).toBe(true);
+    });
+
+    it('should return true when getColorDepth returns >= 24', () => {
+      vi.stubEnv('COLORTERM', '');
+      process.stdout.getColorDepth = vi.fn().mockReturnValue(24);
+      expect(supportsTrueColor()).toBe(true);
+    });
+
+    it('should return false when true color is not supported', () => {
+      vi.stubEnv('COLORTERM', '');
+      process.stdout.getColorDepth = vi.fn().mockReturnValue(8);
+      expect(supportsTrueColor()).toBe(false);
+    });
+  });
+
+  describe('getCompatibilityWarnings', () => {
+    beforeEach(() => {
+      // Default to supporting true color to keep existing tests simple
+      vi.stubEnv('COLORTERM', 'truecolor');
+      process.stdout.getColorDepth = vi.fn().mockReturnValue(24);
+    });
+
+    it('should return Windows 10 warning when detected', () => {
+      vi.mocked(os.platform).mockReturnValue('win32');
+      vi.mocked(os.release).mockReturnValue('10.0.19041');
+      vi.stubEnv('TERMINAL_EMULATOR', '');
+
+      const warnings = getCompatibilityWarnings();
+      expect(warnings).toContain(
+        'Warning: Windows 10 detected. Some UI features like smooth scrolling may be degraded. Windows 11 is recommended for the best experience.',
+      );
+    });
+
+    it('should return JetBrains warning when detected', () => {
+      vi.mocked(os.platform).mockReturnValue('darwin');
+      vi.stubEnv('TERMINAL_EMULATOR', 'JetBrains-JediTerm');
+
+      const warnings = getCompatibilityWarnings();
+      expect(warnings).toContain(
+        'Warning: JetBrains terminal detected. You may experience rendering or scrolling issues. Using an external terminal (e.g., Windows Terminal, iTerm2) is recommended.',
+      );
+    });
+
+    it('should return true color warning when not supported', () => {
+      vi.mocked(os.platform).mockReturnValue('darwin');
+      vi.stubEnv('TERMINAL_EMULATOR', '');
+      vi.stubEnv('COLORTERM', '');
+      process.stdout.getColorDepth = vi.fn().mockReturnValue(8);
+
+      const warnings = getCompatibilityWarnings();
+      expect(warnings).toContain(
+        'Warning: True color (24-bit) support not detected. Using a terminal with true color enabled will result in a better visual experience.',
+      );
+    });
+
+    it('should return all warnings when all are detected', () => {
+      vi.mocked(os.platform).mockReturnValue('win32');
+      vi.mocked(os.release).mockReturnValue('10.0.19041');
+      vi.stubEnv('TERMINAL_EMULATOR', 'JetBrains-JediTerm');
+      vi.stubEnv('COLORTERM', '');
+      process.stdout.getColorDepth = vi.fn().mockReturnValue(8);
+
+      const warnings = getCompatibilityWarnings();
+      expect(warnings).toHaveLength(3);
+      expect(warnings[0]).toContain('Windows 10 detected');
+      expect(warnings[1]).toContain('JetBrains terminal detected');
+      expect(warnings[2]).toContain('True color (24-bit) support not detected');
+    });
+
+    it('should return no warnings in a standard environment with true color', () => {
+      vi.mocked(os.platform).mockReturnValue('darwin');
+      vi.stubEnv('TERMINAL_EMULATOR', '');
+      vi.stubEnv('COLORTERM', 'truecolor');
+
+      const warnings = getCompatibilityWarnings();
+      expect(warnings).toHaveLength(0);
+    });
+  });
+});