fix: Don't crash when rendering the source of an object whose lineno is none

pawamoy · pawamoy · commit 64df00b9b757 · 2024-05-22T17:21:11.000+02:00
Issue-163: mkdocstrings#163
diff --git a/src/mkdocstrings_handlers/python/templates/material/_base/class.html.jinja b/src/mkdocstrings_handlers/python/templates/material/_base/class.html.jinja
@@ -157,7 +157,7 @@ Context:
                         {{ init.relative_filepath }}
                       {%- endif -%}
                     </code></summary>
-                    {{ init.source|highlight(language="python", linestart=init.lineno, linenums=True) }}
+                    {{ init.source|highlight(language="python", linestart=init.lineno or 0, linenums=True) }}
                   </details>
                 {% endwith %}
               {% endif %}
@@ -170,7 +170,7 @@ Context:
                     {{ class.relative_filepath }}
                   {%- endif -%}
                 </code></summary>
-                {{ class.source|highlight(language="python", linestart=class.lineno, linenums=True) }}
+                {{ class.source|highlight(language="python", linestart=class.lineno or 0, linenums=True) }}
               </details>
             {% endif %}
           {% endif %}
diff --git a/src/mkdocstrings_handlers/python/templates/material/_base/function.html.jinja b/src/mkdocstrings_handlers/python/templates/material/_base/function.html.jinja
@@ -133,7 +133,7 @@ Context:
                   {{ function.relative_filepath }}
                 {%- endif -%}
               </code></summary>
-              {{ function.source|highlight(language="python", linestart=function.lineno, linenums=True) }}
+              {{ function.source|highlight(language="python", linestart=function.lineno or 0, linenums=True) }}
             </details>
           {% endif %}
         {% endblock source %}
diff --git a/tests/test_handler.py b/tests/test_handler.py
@@ -4,10 +4,12 @@
 
 import os
 from glob import glob
+from textwrap import dedent
 from typing import TYPE_CHECKING
 
 import pytest
 from griffe.docstrings.dataclasses import DocstringSectionExamples, DocstringSectionKind
+from griffe.tests import temporary_visited_module
 
 from mkdocstrings_handlers.python.handler import CollectionError, PythonHandler, get_handler
 
@@ -145,3 +147,29 @@ def test_extension_paths(tmp_path: Path, expect_change: bool, extension: str | d
             raise ValueError("Normalization must not change extension items type")
     else:
         assert normalized == extension
+
+
+def test_rendering_object_source_without_lineno(handler: PythonHandler) -> None:
+    """Test rendering objects without a line number."""
+    code = dedent(
+        """
+        '''Module docstring.'''
+
+        class Class:
+            '''Class docstring.'''
+
+            def function(self):
+                '''Function docstring.'''
+
+        attribute = 0
+        '''Attribute docstring.'''
+        """,
+    )
+    with temporary_visited_module(code) as module:
+        # TODO: Remove once Griffe does that automatically.
+        module.lines_collection[module.filepath] = code.splitlines()  # type: ignore[index]
+
+        module["Class"].lineno = None
+        module["Class.function"].lineno = None
+        module["attribute"].lineno = None
+        assert handler.render(module, {"show_source": True})
