feat(docs): Ensure multiline JS objects are rendered properly. (#13535)

scripts/tests/autogen.test.ts

@@ -0,0 +1,56 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect } from 'vitest';
+import { formatDefaultValue } from '../utils/autogen.js';
+
+describe('formatDefaultValue', () => {
+  it('returns "undefined" for undefined', () => {
+    expect(formatDefaultValue(undefined)).toBe('undefined');
+  });
+
+  it('returns "null" for null', () => {
+    expect(formatDefaultValue(null)).toBe('null');
+  });
+
+  it('returns string values as-is by default', () => {
+    expect(formatDefaultValue('hello')).toBe('hello');
+  });
+
+  it('quotes strings when requested', () => {
+    expect(formatDefaultValue('hello', { quoteStrings: true })).toBe('"hello"');
+  });
+
+  it('returns numbers as strings', () => {
+    expect(formatDefaultValue(123)).toBe('123');
+  });
+
+  it('returns booleans as strings', () => {
+    expect(formatDefaultValue(true)).toBe('true');
+  });
+
+  it('pretty prints arrays', () => {
+    const input = ['a', 'b'];
+    const expected = JSON.stringify(input, null, 2);
+    expect(formatDefaultValue(input)).toBe(expected);
+    expect(formatDefaultValue(input)).toContain('\n');
+  });
+
+  it('returns "[]" for empty arrays', () => {
+    expect(formatDefaultValue([])).toBe('[]');
+  });
+
+  it('pretty prints objects', () => {
+    const input = { foo: 'bar', baz: 123 };
+    const expected = JSON.stringify(input, null, 2);
+    expect(formatDefaultValue(input)).toBe(expected);
+    expect(formatDefaultValue(input)).toContain('\n');
+  });
+
+  it('returns "{}" for empty objects', () => {
+    expect(formatDefaultValue({})).toBe('{}');
+  });
+});