Building docs fails with AttributeError: 'NoneType' object has no attribute 'replace'

I am using version 1.5.3 of mkdocs and get the following error:

ERROR   -  Error building page 'index.md': 'NoneType' object has no attribute 'replace'
2024-05-06T15:26:05.770035773Z Traceback (most recent call last):
2024-05-06T15:26:05.770039577Z   File "/usr/local/bin/mkdocs", line 8, in <module>
2024-05-06T15:26:05.770043900Z     sys.exit(cli())
2024-05-06T15:26:05.770048151Z              ^^^^^
2024-05-06T15:26:05.770087243Z   File "/usr/local/lib/python3.11/site-packages/click/core.py", line 1157, in __call__
2024-05-06T15:26:05.770092756Z     return self.main(*args, **kwargs)
2024-05-06T15:26:05.770095995Z            ^^^^^^^^^^^^^^^^^^^^^^^^^^
2024-05-06T15:26:05.770099024Z   File "/usr/local/lib/python3.11/site-packages/click/core.py", line 1078, in main
2024-05-06T15:26:05.770102513Z     rv = self.invoke(ctx)
2024-05-06T15:26:05.770105348Z          ^^^^^^^^^^^^^^^^
2024-05-06T15:26:05.770108204Z   File "/usr/local/lib/python3.11/site-packages/click/core.py", line 1688, in invoke
2024-05-06T15:26:05.770111208Z     return _process_result(sub_ctx.command.invoke(sub_ctx))
2024-05-06T15:26:05.770114391Z                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2024-05-06T15:26:05.770117285Z   File "/usr/local/lib/python3.11/site-packages/click/core.py", line 1434, in invoke
2024-05-06T15:26:05.770120205Z     return ctx.invoke(self.callback, **ctx.params)
2024-05-06T15:26:05.770123057Z            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2024-05-06T15:26:05.770126077Z   File "/usr/local/lib/python3.11/site-packages/click/core.py", line 783, in invoke
2024-05-06T15:26:05.770129015Z     return __callback(*args, **kwargs)
2024-05-06T15:26:05.770131852Z            ^^^^^^^^^^^^^^^^^^^^^^^^^^^
2024-05-06T15:26:05.770134749Z   File "/usr/local/lib/python3.11/site-packages/mkdocs/__main__.py", line 286, in build_command
2024-05-06T15:26:05.770137934Z     build.build(cfg, dirty=not clean)
2024-05-06T15:26:05.770140811Z   File "/usr/local/lib/python3.11/site-packages/mkdocs/commands/build.py", line 349, in build
2024-05-06T15:26:05.770143888Z     _build_page(
2024-05-06T15:26:05.770154668Z   File "/usr/local/lib/python3.11/site-packages/mkdocs/commands/build.py", line 235, in _build_page
2024-05-06T15:26:05.770157852Z     output = config.plugins.on_post_page(output, page=page, config=config)
2024-05-06T15:26:05.770160798Z              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2024-05-06T15:26:05.770163789Z   File "/usr/local/lib/python3.11/site-packages/mkdocs/plugins.py", line 586, in on_post_page
2024-05-06T15:26:05.770168042Z     return self.run_event('post_page', output, page=page, config=config)
2024-05-06T15:26:05.770171124Z            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2024-05-06T15:26:05.770174091Z   File "/usr/local/lib/python3.11/site-packages/mkdocs/plugins.py", line 507, in run_event
2024-05-06T15:26:05.770177078Z     result = method(item, **kwargs)
2024-05-06T15:26:05.770179936Z              ^^^^^^^^^^^^^^^^^^^^^^
2024-05-06T15:26:05.770182773Z   File "/usr/local/lib/python3.11/site-packages/mkdocs_puml/plugin.py", line 141, in on_post_page
2024-05-06T15:26:05.770185757Z     page.html = self._replace(v, page.html)
2024-05-06T15:26:05.770188611Z                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
2024-05-06T15:26:05.770194988Z   File "/usr/local/lib/python3.11/site-packages/mkdocs_puml/plugin.py", line 149, in _replace
2024-05-06T15:26:05.770198153Z     return content.replace(
2024-05-06T15:26:05.770200990Z            ^^^^^^^^^^^^^^^
2024-05-06T15:26:05.770203857Z AttributeError: 'NoneType' object has no attribute 'replace'

As far as I can tell this is caused by a faulty if condition in on_post_page(...). There is already a TODO describing why this if is needed:

https://github.com/MikhailKravets/mkdocs_puml/blob/7b007a8b618483a8094615a20f154b9979d5c5e2/mkdocs_puml/plugin.py#L137-L141

It seems like page has the attribute html but the attribute is None. This should be fixed by changing the if as follows:

if hasattr(page, 'html') and page.html is not None:

MikhailKravets / mkdocs_puml

Building docs fails with AttributeError: 'NoneType' object has no attribute 'replace' #39