Fix IDOM preloader trying to parse commented out HTML templates (#106)

* Fix IDOM preloader trying to parse commented out HTML templates
* Fix windows tests with channels >=4.0.0

Author: Archmonger

CHANGELOG.md

@@ -36,6 +36,8 @@ Using the following categories, list your changes in this order:
 -   Allow `use_mutation` to have `refetch=None`, as the docs suggest is possible.
 -   `use_query` will now prefetch all fields to prevent `SynchronousOnlyOperation` exceptions.
 -   `view_to_component`, `django_css`, and `django_js` type hints will now display like normal functions.
+-   IDOM preloader no longer attempts to parse commented out IDOM components.
+-   Tests are now fully functional on Windows
 
 ## [1.2.0] - 2022-09-19
 

requirements/test-env.txt

@@ -1,3 +1,4 @@
 django
 playwright
 twisted
+channels[daphne]>=4.0.0

src/django_idom/utils.py

@@ -18,6 +18,7 @@
 _component_tag = r"(?P<tag>component)"
 _component_path = r"(?P<path>(\"[^\"'\s]+\")|('[^\"'\s]+'))"
 _component_kwargs = r"(?P<kwargs>(.*?|\s*?)*)"
+COMMENT_REGEX = re.compile(r"(<!--)(.|\s)*?(-->)")
 COMPONENT_REGEX = re.compile(
     r"{%\s*"
     + _component_tag
@@ -112,7 +113,8 @@ def _get_components(self, templates: set[str]) -> set[str]:
         for template in templates:
             with contextlib.suppress(Exception):
                 with open(template, "r", encoding="utf-8") as template_file:
-                    regex_iterable = COMPONENT_REGEX.finditer(template_file.read())
+                    clean_template = COMMENT_REGEX.sub("", template_file.read())
+                    regex_iterable = COMPONENT_REGEX.finditer(clean_template)
                     component_paths = [
                         match.group("path").replace('"', "").replace("'", "")
                         for match in regex_iterable

tests/test_app/tests/test_components.py

@@ -1,6 +1,6 @@
+import asyncio
 import os
 import sys
-from unittest import SkipTest
 
 from channels.testing import ChannelsLiveServerTestCase
 from playwright.sync_api import TimeoutError, sync_playwright
@@ -13,13 +13,7 @@ class TestIdomCapabilities(ChannelsLiveServerTestCase):
     @classmethod
     def setUpClass(cls):
         if sys.platform == "win32":
-            raise SkipTest("These tests are broken on Windows.")
-
-            # FIXME: The following lines will be needed once Django channels fixes Windows tests
-            # See: https://github.com/django/channels/issues/1207
-
-            # import asyncio
-            # asyncio.set_event_loop_policy(asyncio.WindowsProactorEventLoopPolicy())
+            asyncio.set_event_loop_policy(asyncio.WindowsProactorEventLoopPolicy())
 
         # FIXME: This is required otherwise the tests will throw a `SynchronousOnlyOperation`
         # error when deleting the test datatabase. Potentially a Django bug.

tests/test_app/tests/test_regex.py

@@ -1,6 +1,6 @@
 from django.test import TestCase
 
-from django_idom.utils import COMPONENT_REGEX
+from django_idom.utils import COMMENT_REGEX, COMPONENT_REGEX
 
 
 class RegexTests(TestCase):
@@ -41,3 +41,45 @@ def test_component_regex(self):
             r'{{ component "" }}',
         }:
             self.assertNotRegex(fake_component, COMPONENT_REGEX)
+
+    def test_comment_regex(self):
+        for comment in {
+            r"<!-- comment -->",
+            r"""<!-- comment
+            -->""",
+            r"""<!--
+             comment -->""",
+            r"""<!--
+            comment
+            -->""",
+            r"""<!-- 
+            a comment
+            another comments
+            drink some cement 
+            -->""",  # noqa: W291
+        }:
+            self.assertRegex(comment, COMMENT_REGEX)
+
+        for fake_comment in {
+            r"<!-- a comment ",
+            r"another comment -->",
+            r"<! - - comment - - >",
+            r'{% component "my.component" %}',
+        }:
+            self.assertNotRegex(fake_comment, COMMENT_REGEX)
+
+        for embedded_comment in {
+            r'{% component "my.component" %} <!-- comment -->',
+            r'<!-- comment --> {% component "my.component" %}',
+            r'<!-- comment --> {% component "my.component" %} <!-- comment -->',
+            r"""<!-- comment
+                    --> {% component "my.component" %}
+                    <!-- comment -->
+                <!--
+                comment -->""",
+        }:  # noqa: W291
+            text = COMMENT_REGEX.sub("", embedded_comment)
+            if text.strip() != '{% component "my.component" %}':
+                raise self.failureException(
+                    f"Regex pattern {COMMENT_REGEX.pattern} failed to remove comment from {embedded_comment}"
+                )