Basic UI testing via playwright, requires Python3 (Fixes #5)

- Includes a dev server test
- Includes a few download button tests

Update readme, and add requirements-test.txt

README.md

@@ -96,4 +96,39 @@ You can contribute to content translation of www.thunderbird.net pages using [Po
 
 # Donation FAQ
 
-The actual questions and answers part of the FAQ can be found in `./faq.py`. Make sure to include the `gettext` call, otherwise we won't be able to extract the strings for localization.
+The actual questions and answers part of the FAQ can be found in `./faq.py`. Make sure to include the `gettext` call, otherwise we won't be able to extract the strings for localization.
+
+# Tests
+
+In order to run tests you will need to install the test dependencies:
+```
+pip install -r requirements-test.txt
+```
+
+If you'll be testing with playwright, you'll also need to do a one-time setup with playwright:
+```
+playwright install
+```
+
+## Pytest
+
+To run all tests use the command: 
+```
+python -m pytest tests/
+```
+
+## Playwright (via Pytest)
+
+Thunderbird-website uses Playwright via the Pytest plugin. For more information on the Playwright Python bindings [click here](https://playwright.dev/python/).
+
+Since the build script only works on Python 2 right now, you'll have to first build the site:
+```
+python2 build-site.py
+```
+
+To run just the playwright tests use the command:
+```
+python -m pytest tests/ui/
+```
+
+Playwright is setup to run UI tests under Firefox and Chromium. 

pytest.ini

@@ -0,0 +1,5 @@
+
+[pytest]
+addopts = --browser firefox --browser chromium
+# webkit doesn't currently work?
+#  --browser webkit

requirements-test.txt

@@ -0,0 +1,3 @@
+# Specific requirements for testing
+pytest==7.3.1
+pytest-playwright==0.3.3

settings.py

@@ -86,6 +86,10 @@
     'zh-hant-hk': 'zh-TW',  # Bug 1338072
 }
 
+TEST_PORT = 8889
+TEST_URL_BASE = 'http://localhost:{}'.format(TEST_PORT)
+TEST_URL = '{}/{}'.format(TEST_URL_BASE, LANGUAGE_CODE)
+
 CANONICAL_URL = 'https://www.thunderbird.net'
 
 # url for the server that serves Thunderbird downloads.

tests/ui/conftest.py

@@ -0,0 +1,15 @@
+import pytest
+
+import builder
+import settings
+
+
+@pytest.fixture(scope="session", autouse=True)
+def handle_server():
+    print("! Starting local test server at {}".format(settings.TEST_URL_BASE))
+    server = builder.setup_httpd(settings.TEST_PORT, settings.WEBSITE_RENDERPATH)
+    yield
+    print("! Shutting down local test server")
+    server.terminate()
+    server.join()
+

tests/ui/test_download_page.py

@@ -0,0 +1,43 @@
+import re
+import pytest
+from playwright.sync_api import Page, expect
+from product_details import thunderbird_desktop
+import settings
+
+@pytest.fixture
+def download_page_download_states(page: Page):
+    """Returns a list of tuples, which contains the download page to goto, and the download version the visible download button should be."""
+    download_page_url = f"{settings.TEST_URL}/download/"
+
+    download_versions = (
+        thunderbird_desktop.latest_version('release'),
+        thunderbird_desktop.latest_version('beta'),
+        thunderbird_desktop.latest_version('daily')
+    )
+
+    return [
+        (download_page_url, download_versions[0]),
+        (f"{download_page_url}?downloaded=True", download_versions[0]),
+        (f"{download_page_url}?downloaded=False", download_versions[0]),
+        (f"{download_page_url}?download_channel=esr", download_versions[0]),
+        (f"{download_page_url}?download_channel=beta", download_versions[1]),
+        (f"{download_page_url}?download_channel=daily", download_versions[2]),
+        (f"{download_page_url}?download_channel=nonsense", download_versions[0]),
+        (f"{download_page_url}?download_channel=&downloaded=true&download_channel=beta", download_versions[1]),  # Javascript check looks for (esr|beta|daily), empty params are ignored
+        (f"{download_page_url}?download_channel=&downloaded=true&download_channel=daily&download_channel=beta", download_versions[2]),  # Javascript check will only use the first instance
+    ]
+
+
+def test_download_links_exist(page: Page, download_page_download_states):
+    """Tests the existence of the `Try Again` button on our download thank you page."""
+    for state in download_page_download_states:
+        page.goto(state[0])
+        expect(page.locator('.download-link:visible')).to_have_count(1)
+
+
+def test_download_links_are_correct(page: Page, download_page_download_states):
+    """Tests the validity of our download buttons when different download channels have been requested."""
+    for state in download_page_download_states:
+        page.goto(state[0])
+        expect(page.locator('.download-link:visible')).to_have_attribute("href", re.compile(state[1]))
+

tests/ui/test_local_server.py

@@ -0,0 +1,14 @@
+import pytest
+import settings
+from playwright.sync_api import Page, expect
+
+
+def test_server_is_working(page: Page):
+    """Make sure our test server works correctly"""
+    response = page.goto(settings.TEST_URL)
+    assert response is not None
+    assert response.ok is True
+
+    # Make sure our title is correct, and this isn't an empty 200.
+    expect(page).to_have_title('Thunderbird — Make Email Easier. — Thunderbird')
+