fix: endblock falsely reported as uncovered when on its own line (issue #74)

In parent templates, a TEXT token inside a {% block %} can end with a
whitespace-only fragment before {% endblock %} with no newline terminator.
That fragment is not an executable line but was incorrectly added to
source_lines, causing {% endblock %} to appear as an uncovered line.

Skip the trailing fragment when inside a block (inblock=True).

Author: marcgibbons

django_coverage_plugin/plugin.py

@@ -349,6 +349,13 @@ def lines(self):
                 if lines[0].isspace():
                     lineno += 1
                     num_lines -= 1
+                # When {% endblock %} is not at the start of a line, the
+                # preceding TEXT token ends with whitespace and no newline.
+                # That partial line is not executable content.
+                if inblock and num_lines > 0 and (
+                    lines[-1].isspace() and not lines[-1].endswith(("\n", "\r"))
+                ):
+                    num_lines -= 1
                 source_lines.update(range(lineno, lineno+num_lines))
 
             if SHOW_PARSING:

tests/test_extends.py

@@ -8,6 +8,74 @@
 
 class BlockTest(DjangoPluginTestCase):
 
+    def test_empty_parent_block_on_new_line_when_extended(self):
+        """
+        When a block is empty and extended, endblock should not appear
+        as an uncovered line.
+
+        https://github.com/coveragepy/django_coverage_plugin/issues/74
+        """
+        self.make_template(name="base.html", text="""\
+            Hello
+              {% block content %}
+              {% endblock content %}
+            Goodbye
+            """)
+        self.make_template(name="child.html", text="""\
+            {% extends "base.html" %}
+            {% block content %}
+              Override
+            {% endblock %}
+            """)
+        text = self.run_django_coverage(name="child.html")
+        self.assert_analysis([1, 2, 4], name="base.html")
+        self.assert_analysis([1, 3], name="child.html")
+        self.assertEqual(text.strip(), "Hello\n  \n  Override\n\nGoodbye")
+
+    def test_non_empty_parent_block_when_extended(self):
+        self.make_template(name="base.html", text="""\
+            Hello
+              {% block content %}
+                This line should be reported as uncovered.
+              {% endblock content %}
+            Goodbye
+            """)
+        self.make_template(name="child.html", text="""\
+            {% extends "base.html" %}
+            {% block content %}
+              Override
+            {% endblock %}
+            """)
+        text = self.run_django_coverage(name="child.html")
+        self.assert_analysis([1, 2, 3, 5], missing=[3], name="base.html")
+        self.assert_analysis([1, 3], name="child.html")
+
+        self.assertEqual(text.strip(), "Hello\n  \n  Override\n\nGoodbye")
+
+    def test_nested_blocks_outer_endblock_on_its_own_line(self):
+        """
+        When blocks are nested, on their own lines, and extended,
+        then endblock should not appear as uncovered.
+
+        Ref: https://github.com/coveragepy/django_coverage_plugin/issues/74
+        """
+        self.make_template(name="base.html", text="""\
+            {% block outer %}
+              {% block inner %}
+              {% endblock inner %}
+            {% endblock outer %}
+            """)
+        self.make_template(name="child.html", text="""\
+            {% extends "base.html" %}
+            {% block inner %}
+              Override
+            {% endblock %}
+            """)
+        text = self.run_django_coverage(name="child.html")
+        self.assert_analysis([1, 2], missing=[], name="base.html")
+        self.assert_analysis([1, 3], name="child.html")
+        self.assertEqual(text.strip(), "Override")
+
     def test_empty_block(self):
         self.make_template("""\
             {% block somewhere %}{% endblock %}