Add a configuration option to allow block tags to be excluded by regex

README.rst

@@ -91,15 +91,15 @@ extensions if you like::
     [django_coverage_plugin]
     template_extensions = html, txt, tex, email
 
-If you use ``pyproject.toml`` for tool configuration use::
+Block tags can be excluded using regexes to match the block content;
+for example, to exclude a custom template tag ``{% my_tag ... %}``, use::
 
-    [tool.coverage.run]
-    plugins = [
-        'django_coverage_plugin',
-    ]
+    [run]
+    plugins = django_coverage_plugin
+
+    [django_coverage_plugin]
+    exclude_blocks = ["my_tag.+"]
 
-    [tool.coverage.django_coverage_plugin]
-    template_extensions = 'html, txt, tex, email'
 
 Caveats
 ~~~~~~~

django_coverage_plugin/plugin.py

@@ -6,6 +6,8 @@
 import os.path
 import re
 
+from coverage.misc import join_regex
+
 try:
     from coverage.exceptions import NoSource
 except ImportError:
@@ -149,6 +151,8 @@ class DjangoTemplatePlugin(
     def __init__(self, options):
         extensions = options.get("template_extensions", "html,htm,txt")
         self.extensions = [e.strip() for e in extensions.split(",")]
+
+        self.exclude_blocks = options.get("exclude_blocks")
 
         self.debug_checked = False
 
@@ -184,7 +188,7 @@ def file_tracer(self, filename):
         return None
 
     def file_reporter(self, filename):
-        return FileReporter(filename)
+        return FileReporter(filename, self.exclude_blocks)
 
     def find_executable_files(self, src_dir):
         # We're only interested in files that look like reasonable HTML
@@ -292,10 +296,16 @@ def get_line_map(self, filename):
 
 
 class FileReporter(coverage.plugin.FileReporter):
-    def __init__(self, filename):
+    def __init__(self, filename, exclude_blocks):
         super().__init__(filename)
         # TODO: html filenames are absolute.
 
+        if exclude_blocks:
+            self.exclude_blocks_regex = re.compile(join_regex(exclude_blocks))
+        else:
+            self.exclude_blocks_regex = None
+        self._excluded = set()
+
         self._source = None
 
     def source(self):
@@ -351,6 +361,12 @@ def lines(self):
                     # In an inheriting template, ignore all tags outside of
                     # blocks.
                     continue
+
+                # Ignore any block token content that has been explcitly
+                # excluded in config
+                if self.exclude_block_token(token):
+                    self._excluded.add(token.lineno)
+                    continue
 
                 if token.contents == "comment":
                     comment = True
@@ -389,6 +405,12 @@ def lines(self):
 
         return source_lines
 
+    def excluded_lines(self):
+        return self._excluded
+
+    def exclude_block_token(self, token):
+        if self.exclude_blocks_regex:
+            return self.exclude_blocks_regex.search(token.contents)
 
 def running_sum(seq):
     total = 0

tests/test_simple.py

@@ -264,3 +264,30 @@ def test_with_branch_enabled(self):
             )
         self.assertEqual(text, 'Hello\nWorld\n\nGoodbye')
         self.assert_analysis([1, 2, 3, 4])
+
+
+class ExcludeTest(DjangoPluginTestCase):
+    """Tests of excluding block tokens by regex."""
+
+    def test_exclude_block(self):
+        self.make_template("""\
+            First
+            {% with foo='bar' %}
+                {{ foo }}
+            {% endwith %}
+            Last
+            """)
+        text = self.run_django_coverage()
+        self.assertEqual(text, "First\n\n    bar\n\nLast\n")
+        self.assert_analysis([1, 2, 3, 5])
+
+        self.make_file(".coveragerc", """\
+            [run]
+            plugins = django_coverage_plugin
+            [django_coverage_plugin]
+            exclude_blocks = [".+foo.+"]
+            """)
+
+        text = self.run_django_coverage()
+        self.assertEqual(text, "First\n\n    bar\n\nLast\n")
+        self.assert_analysis([1, 3, 5])