doctest-mode is an Emacs major mode for editing text files that contain Python doctest examples. Doctest is a testing framework for Python that emulates an interactive session, and checks the result of each command. For more information, see the Python library reference documentation on doctest. doctest-mode makes it easier to write and maintain doctest files, by providing:

• Syntax highlighting of the prompts, source code, and expected output for each doctest example.
• Editing support, including automatic indentation (similar to python-mode) and automatic prompt management.
• Execution support, allowing you to run doctest directly from emacs, and examine the results in an output buffer.
• Failure navigation, allowing you to quickly navigate between failed examples after you run doctest.
• Output replacement, allowing you to easily update doctest examples with the correct output value.

It was written by Edward Loper in August 2004, the official page is : https://ed.loper.org/projects/doctestmode/ with a well done documentation.

It is still part of python-mode project, successively hosted at

• Sourceforge: https://sourceforge.net/projects/python-mode/
• Launchpad : https://launchpad.net/python-mode
• GitLab : https://gitlab.com/python-mode-devs/python-mode

But as of today (July 31, 2017), at the same versions:

• 2004: doctest-mode 0.4 (official release)
• 2007: doctest-mode 0.5 (alpha release – adds mmm-mode suppor bbt)

If you’re interested in full project history you may use the links above, I started this version tracking from the last versions. The 0.5 alpha release is in the branch named mmm_support .

I’m not using mmm-mode so I started working from the r0.4 version. It was working well enough in my emacs 25.2.1 (spacemacs) but the great Output replacement feature was sadly failing at (just following the online demo ) at line 1366:

(replace-match doctest-got t t)

The byte compilation was triggering many warnings, so I simply started doing the proposed source code modifications:

• assignment to free variables:
  • doctest-selected-failure
  • doctest-async-process
  • doctest-results-buffer
  • doctest-source-buffer
  • doctest-async-process-tempfile
  • doctest-async-process
  • doctest-example-markers
  • doctest-selected-failure
• ‘delete-backward-char’ is for interactive use only; use ‘delete-char’ instead.
• ‘insert-string’ is an obsolete function (as of 22.1); use ‘insert’ instead.
• doctest-looking-back called with 1 argument, but requires 2-3
• Use ‘with-current-buffer’ rather than save-excursion+set-buffer
• ‘toggle-read-only’ is an obsolete function (as of 24.3); use ‘read-only-mode’ instead.
• ‘string-to-int’ is an obsolete function (as of 22.1); use ‘string-to-number’ instead.

Those changes should not break compatibility with earlier versions, even pre-22.1, but I did not check.

However, this solved the issue on `doctest-replace-output` .

Doctest-mode was first written by Edward Loper in August 2004 and 2007, the official page is :

https://ed.loper.org/projects/doctestmode/