test: add comprehensive validation for recent version discovery

Adds test coverage for the new scrapeRecentOfficialUnityVersions() function:

**Unit tests:**
- Multiple version discovery from releases page
- Multiple changeset extraction patterns (unityhub URLs, Changeset markers, proximity)
- Deduplication of duplicate versions
- Skipping versions without valid changesets
- Filtering non-final versions (alpha, beta, etc)
- Error handling for page fetch failures

**Integration test (CI-only):**
- Live test that fetches real Unity releases page
- Validates regex patterns work against actual HTML
- Ensures changesets are correctly extracted
- Catches when Unity page structure changes
- Only runs in GitHub Actions CI environment

This ensures the scraping logic stays valid as Unity's releases page structure evolves,
enabling teams to work without Firestore access while maintaining confidence the system
will discover new versions responsively.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Author: frostebite

functions/test/scrapeVersions.test.ts

@@ -2,6 +2,7 @@ import { describe, it, expect, vi, beforeEach } from 'vitest';
 import {
   scrapeLatestOfficialUnityVersion,
   scrapeVersions,
+  scrapeRecentOfficialUnityVersions,
 } from '../src/logic/ingestUnityVersions/scrapeVersions';
 import { SearchMode } from 'unity-changeset';
 import fetch from 'node-fetch';
@@ -337,3 +338,199 @@ describe('scrapeVersions', () => {
     await expect(scrapeVersions()).rejects.toThrow('No Unity versions found!');
   });
 });
+
+describe('scrapeRecentOfficialUnityVersions', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('should discover multiple recent versions from the releases page', async () => {
+    const html = `
+      <h1>Unity 6000.4.10f1</h1>
+      <a href="unityhub://6000.4.10f1/feeafc12a938">Install</a>
+
+      <h2>Unity 6000.3.17f1</h2>
+      <p>Changeset: abc123def456</p>
+
+      <h2>Unity 6000.2.5f1</h2>
+      <a href="unityhub://6000.2.5f1/xyz789uvw123">Download</a>
+    `;
+    mockedFetch.mockResolvedValue({
+      ok: true,
+      status: 200,
+      text: async () => html,
+    } as any);
+
+    const result = await scrapeRecentOfficialUnityVersions();
+
+    expect(result).toHaveLength(3);
+    expect(result.map((v) => v.version)).toContain('6000.4.10f1');
+    expect(result.map((v) => v.version)).toContain('6000.3.17f1');
+    expect(result.map((v) => v.version)).toContain('6000.2.5f1');
+  });
+
+  it('should extract changesets from unityhub:// URLs', async () => {
+    const html = `
+      <a href="unityhub://6000.4.10f1/feeafc12a938">Install</a>
+      <a href="unityhub://6000.3.17f1/abc123def456">Install</a>
+    `;
+    mockedFetch.mockResolvedValue({
+      ok: true,
+      status: 200,
+      text: async () => html,
+    } as any);
+
+    const result = await scrapeRecentOfficialUnityVersions();
+
+    expect(result).toContainEqual(
+      expect.objectContaining({
+        version: '6000.4.10f1',
+        changeSet: 'feeafc12a938',
+      }),
+    );
+    expect(result).toContainEqual(
+      expect.objectContaining({
+        version: '6000.3.17f1',
+        changeSet: 'abc123def456',
+      }),
+    );
+  });
+
+  it('should extract changesets from "Changeset:" markers', async () => {
+    const html = `
+      <h2>Unity 6000.4.10f1</h2>
+      <p>Changeset: feeafc12a938</p>
+
+      <h2>Unity 6000.3.17f1</h2>
+      <div>Version Changeset: abc123def456</div>
+    `;
+    mockedFetch.mockResolvedValue({
+      ok: true,
+      status: 200,
+      text: async () => html,
+    } as any);
+
+    const result = await scrapeRecentOfficialUnityVersions();
+
+    expect(result).toContainEqual(
+      expect.objectContaining({
+        version: '6000.4.10f1',
+        changeSet: 'feeafc12a938',
+      }),
+    );
+    expect(result).toContainEqual(
+      expect.objectContaining({
+        version: '6000.3.17f1',
+        changeSet: 'abc123def456',
+      }),
+    );
+  });
+
+  it('should skip versions without valid changesets', async () => {
+    const html = `
+      <h2>Unity 6000.4.10f1</h2>
+      <a href="unityhub://6000.4.10f1/feeafc12a938">Install</a>
+
+      <h2>Unity 6000.3.17f1</h2>
+      <!-- No changeset provided -->
+
+      <h2>Unity 6000.2.5f1</h2>
+      <p>Changeset: xyz789uvw123</p>
+    `;
+    mockedFetch.mockResolvedValue({
+      ok: true,
+      status: 200,
+      text: async () => html,
+    } as any);
+
+    const result = await scrapeRecentOfficialUnityVersions();
+
+    // Only versions with valid changesets should be included
+    expect(result).toHaveLength(2);
+    expect(result.map((v) => v.version)).not.toContain('6000.3.17f1');
+  });
+
+  it('should deduplicate versions found multiple times on the page', async () => {
+    const html = `
+      <h2>Unity 6000.4.10f1</h2>
+      <a href="unityhub://6000.4.10f1/feeafc12a938">Install</a>
+
+      <p>Latest version: 6000.4.10f1</p>
+      <a href="unityhub://6000.4.10f1/feeafc12a938">Download</a>
+    `;
+    mockedFetch.mockResolvedValue({
+      ok: true,
+      status: 200,
+      text: async () => html,
+    } as any);
+
+    const result = await scrapeRecentOfficialUnityVersions();
+
+    expect(result).toHaveLength(1);
+    expect(result[0].version).toBe('6000.4.10f1');
+  });
+
+  it('should return empty array if page returns error', async () => {
+    mockedFetch.mockResolvedValue({
+      ok: false,
+      status: 404,
+    } as any);
+
+    await expect(scrapeRecentOfficialUnityVersions()).rejects.toThrow(
+      'Unity release page returned 404',
+    );
+  });
+
+  it('should filter out non-final versions', async () => {
+    const html = `
+      <h2>Unity 6000.4.10f1</h2>
+      <a href="unityhub://6000.4.10f1/feeafc12a938">Install</a>
+
+      <h2>Unity 6000.4.10a1</h2>
+      <a href="unityhub://6000.4.10a1/abc123456789">Install</a>
+
+      <h2>Unity 6000.4.9f1</h2>
+      <p>Changeset: xyz789uvw123</p>
+    `;
+    mockedFetch.mockResolvedValue({
+      ok: true,
+      status: 200,
+      text: async () => html,
+    } as any);
+
+    const result = await scrapeRecentOfficialUnityVersions();
+
+    expect(result).toHaveLength(2);
+    expect(result.map((v) => v.version)).toContain('6000.4.10f1');
+    expect(result.map((v) => v.version)).toContain('6000.4.9f1');
+    expect(result.map((v) => v.version)).not.toContain('6000.4.10a1');
+  });
+
+  describe('integration test (live)', () => {
+    it.skipIf(process.env.CI === 'false')('should successfully scrape real Unity releases page', async () => {
+      // This test runs in CI only and validates the scraping logic against the real page
+      const realFetch = (await import('node-fetch')).default;
+      vi.mocked(fetch).mockImplementation(realFetch as any);
+
+      const result = await scrapeRecentOfficialUnityVersions();
+
+      // Should find at least some recent versions
+      expect(result.length).toBeGreaterThan(0);
+
+      // All versions should be valid
+      result.forEach((version) => {
+        expect(version.version).toMatch(/^\d+\.\d+\.\d+f\d+$/);
+        expect(version.changeSet).toMatch(/^[a-f0-9]{12}$/);
+        expect(version.major).toBeGreaterThanOrEqual(2017);
+      });
+
+      console.log(`Found ${result.length} recent versions on Unity releases page`);
+      console.log(
+        `Latest versions: ${result
+          .slice(0, 5)
+          .map((v) => v.version)
+          .join(', ')}`,
+      );
+    });
+  });
+});