doccmd

A command line tool for running commands against code blocks in documentation files. This allows you to run linters, formatters, and other tools against the code blocks in your documentation files.

• Installation
  • With pip
  • With Homebrew (macOS, Linux, WSL)
    • Pre-built Linux binaries
  • Using doccmd as a pre-commit hook
• Usage example
• What does it work on?
• Formatters and padding
• File names and linter ignores
• Skipping code blocks
• Full documentation

Installation

With pip

Requires Python 3.10+.

pip install doccmd

With Homebrew (macOS, Linux, WSL)

Requires Homebrew.

brew tap adamtheturtle/doccmd
brew install doccmd

Pre-built Linux binaries

$ curl --fail -L https://github.com/adamtheturtle/doccmd/releases/download/2024.09.27/doccmd -o /usr/local/bin/doccmd && \
$ chmod +x /usr/local/bin/doccmd

Using doccmd as a pre-commit hook

To run doccmd with pre-commit, add hooks like the following to your .pre-commit-config.yaml:

-   repo: https://github.com/adamtheturtle/doccmd-pre-commit
    rev: v2024.09.27
    hooks:
    -   id: doccmd
        args: ["--language", "shell", "--command", "shellcheck --shell=bash"]
        additional_dependencies: ["shellcheck-py"]

Usage example

# Run mypy against the Python code blocks in README.md and CHANGELOG.rst
$ doccmd --language=python --command="mypy" README.md CHANGELOG.rst

# Run gofmt against the Go code blocks in README.md
# This will modify the README.md file in place
$ doccmd --language=go --command="gofmt -w" README.md

# or type less...
$ doccmd -l python -c mypy README.md CHANGELOG.rst

What does it work on?

• reStructuredText (.rst)

.. code-block:: shell

   echo "Hello, world!"

.. code:: shell

   echo "Or this Hello, world!"

• Markdown (.md)

```shell
echo "Hello, world!"
```

• MyST (.md with MyST syntax)

```{code-block} shell
echo "Hello, world!"
```

```{code} shell
echo "Or this Hello, world!"
```

• Want more? Open an issue!

Formatters and padding

Running linters with doccmd gives you errors and warnings with line numbers that match the documentation file. It does this by adding padding to the code blocks before running the command.

Some tools do not work well with this padding, and you can choose to obscure the line numbers in order to give the tool the original code block's content without padding, by using the --no-pad-file flag.

File names and linter ignores

doccmd creates temporary files for each code block in the documentation file. These files are created in the same directory as the documentation file, and are named with the documentation file name and the line number of the code block. Files are created with a prefix set to the given --file-name-prefix argument (default doccmd).

You can use this information to ignore files in your linter configuration.

For example, to ignore a rule in all files created by doccmd in a ruff configuration in pyproject.toml:

[tool.ruff]

lint.per-file-ignores."doccmd_*.py" = [
   # Allow hardcoded secrets in documentation.
   "S105",
]

Skipping code blocks

Code blocks which come just after a comment matching skip doccmd[all]: next are skipped.

For example:

• reStructuredText (.rst)

.. skip doccmd[all]: next

.. code-block:: shell

   echo "This will be skipped!"

.. code-block:: shell

   echo "This will run"

• Markdown (.md)

<-- skip doccmd[all]: next -->

```shell
echo "This will be skipped!"
```

```shell
echo "This will run"
```

• MyST (.md with MyST syntax)

% skip doccmd[all]: next

```{code-block} shell
echo "This will be skipped!"
```

```{code-block} shell
echo "This will run"
```

To skip multiple code blocks in a row, use skip doccmd[all]: start and skip doccmd[all]: end surrounding the code blocks to skip.

Use the --skip-marker option to set a marker for this particular command which will work as well as "all". For example, use --skip-marker="type-check" to skip code blocks which come just after a comment matching skip doccmd[type-check]: next. This marker is matched using a regular expression.

Full documentation

See the full documentation.