diff --git a/packages/core/src/ide/detect-ide.test.ts b/packages/core/src/ide/detect-ide.test.ts
new file mode 100644
index 00000000000..c868090c832
--- /dev/null
+++ b/packages/core/src/ide/detect-ide.test.ts
@@ -0,0 +1,39 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
+import { DetectedIde, getIdeDisplayName, detectIde } from './detect-ide.js';
+
+describe('detect-ide', () => {
+  describe('getIdeDisplayName', () => {
+    it('should return "VS Code" for DetectedIde.VSCode', () => {
+      expect(getIdeDisplayName(DetectedIde.VSCode)).toBe('VS Code');
+    });
+  });
+
+  describe('detectIde', () => {
+    afterEach(() => {
+      vi.unstubAllEnvs();
+    });
+
+    it('should return DetectedIde.VSCode if TERM_PROGRAM is vscode', () => {
+      vi.stubEnv('TERM_PROGRAM', 'vscode');
+      expect(detectIde()).toBe(DetectedIde.VSCode);
+    });
+
+    it('should return undefined if TERM_PROGRAM is not vscode', () => {
+      vi.stubEnv('TERM_PROGRAM', 'something-else');
+      expect(detectIde()).toBeUndefined();
+    });
+
+    it('should return undefined if TERM_PROGRAM is not set', () => {
+      // Vitest's vi.unstubAllEnvs or setting to empty isn't perfectly unsetting it, but we can set it to undefined explicitly
+      // Actually, let's just use stubEnv to remove it temporarily
+      vi.stubEnv('TERM_PROGRAM', '');
+      expect(detectIde()).toBeUndefined();
+    });
+  });
+});