Fix internal anchor in included file incorrectly rewritten (#267)

Author: mondeja

examples/internal-anchors/docs/index.md

@@ -0,0 +1,3 @@
+{%
+   include-markdown "../test.md"
+%}

examples/internal-anchors/mkdocs.yml

@@ -0,0 +1,5 @@
+site_name: My Docs
+site_url: https://example.com/org-name/repo-name/
+
+plugins:
+  - include-markdown

examples/internal-anchors/test.md

@@ -0,0 +1,7 @@
+# First level heading
+
+Example data
+
+## Second level heading
+
+Link to [second level heading](#second-level-heading).

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "mkdocs-include-markdown-plugin"
-version = "7.1.5"
+version = "7.1.6"
 description = "Mkdocs Markdown includer plugin."
 readme = "README.md"
 license = "Apache-2.0"

src/mkdocs_include_markdown_plugin/process.py

@@ -291,7 +291,7 @@ def rewrite_relative_urls(
     ``destination_path``.
     """
     def rewrite_url(url: str) -> str:
-        if is_url(url) or is_absolute_path(url):
+        if is_url(url) or is_absolute_path(url) or is_anchor(url):
             return url
 
         new_path = os.path.relpath(
@@ -583,6 +583,17 @@ def is_absolute_path(string: str) -> bool:
         return False
 
 
+def is_anchor(string: str) -> bool:
+    """Check if a string looks like an anchor.
+
+    An anchor is a string that starts with `#` and is not a relative path.
+    """
+    try:
+        return string[0] == '#'
+    except IndexError:  # pragma: no cover
+        return False
+
+
 def read_file(file_path: str, encoding: str) -> str:
     """Read a file and return its content."""
     f = open(file_path, encoding=encoding)  # noqa: SIM115

tests/test_unit/test_process.py

@@ -125,7 +125,7 @@
              " class='bar'>example</a>"),
             id='html-anchor-single-quote',
         ),
-        # HTML Relative Links Adverarial tests:
+        # HTML Relative Links Adversarial tests:
         # (attribute contains >, attribute without value, multiple tag in line)
         pytest.param(
             ('<img id="foo" attr="3>2" attr2 src="assets/diagram.png"'
@@ -136,7 +136,7 @@
             ('<img id="foo" attr="3>2" attr2 src="../assets/diagram.png"'
              ' alt="diagram" class="bar" /><img id="foo" attr="3>2"'
              ' src="../assets/diagram.png" alt="diagram" class="bar" />'),
-            id='html-image-adverarial-test',
+            id='html-image-adversarial-test',
         ),
         pytest.param(
             ('<a id="foo" attr="3>2" attr2 href="badge.png" class="bar">'
@@ -147,7 +147,7 @@
             ('<a id="foo" attr="3>2" attr2 href="../badge.png" class="bar">'
              'foo</a><a id="foo" attr="3>2" href="../badge.png" class="bar">'
              'bar</a>'),
-            id='html-anchor-adverarial-test',
+            id='html-anchor-adversarial-test',
         ),
         # HTML Relative Links Adversarial test: img no end slash
         pytest.param(
@@ -362,6 +362,15 @@
             # https://spec.commonmark.org/0.28/#indented-code-blocks
             id='no-exclude-indented-code-blocks-missing-newline-after',
         ),
+        # Internal anchor in included file
+        # https://github.com/mondeja/mkdocs-include-markdown-plugin/issues/266
+        pytest.param(
+            'This is a link to an [internal anchor](#internal-anchor).',
+            'README',
+            'docs/nav.md',
+            'This is a link to an [internal anchor](#internal-anchor).',
+            id='internal-anchor',
+        ),
     ),
 )
 def test_rewrite_relative_urls(