I'm too lazy to manually check code blocks in autogenerated sphinx documentation to see if they are valid and reasonably up to date. Doing it automatically feels much more interesting to me: here's how I did it.
This is a simple sphinx extension to extract code blocks in a JSON file.
If the documentation is written well enough, I even get annotation on what programming language each snippet is made of:
## Extract code blocks from sphinx from docutils.nodes import literal_block, Text import json found = [] def find_code(app, doctree, fromdocname): for node in doctree.traverse(literal_block): # if "dballe.DB.connect" in str(node): lang = node.attributes.get("language", "default") for subnode in node.traverse(Text): found.append({ "src": fromdocname, "lang": lang, "code": subnode, "source": node.source, "line": node.line, }) def output(app, exception): if exception is not None: return dest = app.config.test_code_output if dest is None: return with open(dest, "wt") as fd: json.dump(found, fd) def setup(app): app.add_config_value('test_code_output', None, '') app.connect('doctree-resolved', find_code) app.connect('build-finished', output) return { "version": '0.1', 'parallel_read_safe': True, 'parallel_write_safe': True, }
And this is an early prototype python code that runs each code block in a subprocess to see if it works.
It does interesting things, such as:
- Walk the AST to see if the code expects some well known variables to have been set, and prepare the test environment accordingly
- Collect DeprecationWarnings to spot old snippets using deprecated functions
- Provide some unittest-like
assert*
functions that snippets can then use if they want - Run every snippet in a subprocess, which then runs in a temporary directory, deleted after execution
- Colorful output, including highlighting of code lines that threw exceptions