Add unit tests for the getSystemPrompt function in prompts.test.ts.

app/lib/common/prompts/prompts.test.ts

@@ -0,0 +1,20 @@
+import { describe, expect, it } from 'vitest';
+import { getSystemPrompt } from './prompts';
+import { MODIFICATIONS_TAG_NAME, WORK_DIR } from '~/utils/constants';
+import { allowedHTMLElements } from '~/utils/markdown';
+
+describe('getSystemPrompt', () => {
+  it('should return system prompt with default work dir', () => {
+    const result = getSystemPrompt();
+    expect(result).toContain(`The current working directory is \`${WORK_DIR}\`.`);
+    expect(result).toContain(`<${MODIFICATIONS_TAG_NAME}>`);
+    expect(result).toContain(`</${MODIFICATIONS_TAG_NAME}>`);
+    expect(result).toContain(allowedHTMLElements.map((tag) => `<${tag}>`).join(', '));
+  });
+
+  it('should use provided working directory', () => {
+    const customDir = '/custom/dir';
+    const result = getSystemPrompt(customDir);
+    expect(result).toContain(`The current working directory is \`${customDir}\`.`);
+  });
+});