CheckMyTex

A tool to comfortably check complex LaTeX documents, e.g., dissertations, for common errors. There are already pretty good correction tools for LaTex, e.g., TeXtidote, YaLafi (of which we use the tex2text engine), or LaTeXBuddy (in which I was involved and of which I copied some things), but they had shortcomings with complex documents, and they also did not fit my workflow. CheckMyTex builds upon YaLafi, but provides a simple CLI with some additional magic and tricks to deal with hopefully any document. The primary difference to its main contenders is the focus on CLI and whitelists.

⚠️ Your terminal needs to support rich (should be most terminals)!

Primary concepts are

• not just listing problems but also their exact locations,
• working on the whole document, not just individual files (because otherwise, you forget to check some files),
• lots of predefined rules such as newcommand-substitution, todo-removal, etc.,
• simple extension of further checking modules,
• ability to whitelist found problems and share this whitelist,
• edit the errors directly (in Vim with automatic jump to line), and
• having a single, simple command that you can easily run before every commit.

This tool has a fancy HTML-output (like other tools), but its primary intention is to be used as CLI:

1. Thanks to colored output, the highlighting works just as nice in CLI as in HTML. No need to switch to your browser.
2. The CLI can use your favourite editor (currently, only (n)vim and nano have full support) without switching context.

An example output can be seen here. The CLI version looks nearly identical (thanks to rich, but you are iteratively asked how to deal with each problem.

What does CheckMyTex currently check for you?

• Spelling errors using aspell or pyspellchecker
• Grammar errors using languagetool
• LaTeX-smells using ChkTeX
• Raw numbers instead of siunitx (simple regex, showing you how easy new modules can be added)
• Additional advise from proselint
• (Correct) usage of cleveref.
• Uniform writing style of NP-hard/complete (this is probably a problem only within my community, but it doesn't harm you)

I found this set of tools to be sufficient to find most problems in text and LaTeX-source, and I am constantly surprised on how well it works.

The sources are detexed before applying grammar or spelling checking using YaLafi.

Further checks may be added in the future. I do a lot of collaborative writing on papers and am constantly confronted with bad LaTeX that I try to detect automatically.

Install

You can install CheckMyTex using pip (if you have Python3 installed)

pip install checkmytex

You additionally need to install languagetool and a LaTeX-distribution (which should contain ChkTeX). To have a better spell checker, you should also install aspell and the corresponding dictionaries. All these should be available via yours systems package manages, e.g. pacman, apt, or brew.

⚠️ This tool currently only supports Unix (Linux and Mac OS). It could work in some windows configurations, but probably you get some unexpected behavior due to incompatible system calls.

Mac

brew install --cask mactex  # install a tex distribution
brew install languagetool  # install the grammar checker languagetool
brew install aspell  # install a dictionary

Arch Linux

sudo pacman -S texlive-most languagetool aspell aspell-en

Usage

checkmytex main.tex

CheckMyTex will now guide you through your document and show you all problems, skipping over good parts. For each problem, you will be asked what to do

[s]kip,[S]kip all,[w]hitelist,[I]gnore all,[n]ext file,[e]dit,[l]ook up,[f]ind,[?]:

• skip will skip this concrete problem, but ask you again next time you run CheckMyTex.
• Skip all will skip this problem and all identical problems, but ask you again on the next run of CheckMyTex.
• whitelist will whitelist the problem and never ask you about it again (for this document).
• Ignore will ignore all problems that belong to the same rule, but ask you again next time you run CheckMyTex.
• next file will jump to the next file.
• edit will open you $EDITOR at the location of the problem. It tries to keep track of line changes without reprocessing the document.
• look up will google the problem for you (if available). E.g., you can check for rare technical terms.
• find allows to search with a regular expression for further occurrences. Use this, e.g., to find a uniform spelling.
• ? provides further information of the problem. Primarily for debugging and fine-tuning.

Whitelisted problems are by default saved in .whitelist.txt (document root) and are human-readable. You can copy it to use also for other documents or change the path using the -w argument with a path when calling CheckMyTex.

This tool will have problems with some areas of you document. You can exclude these areas by adding lines with %%PAUSE-CHECKING and %%CONTINUE-CHECKING. This may be easier than whitelisting all the problems.

The time to check a 300-page dissertation is around a few seconds. A better spell checking would be available but drastically increase the runtime.

If you want to process the output with another tool, you can export the result as json using:

checkmytex --json analysis.json main.tex

If you want an HTML-document you can share with your co-authors, use

checkmytex --html analysis.html main.tex

Extending CheckMyTex

Finding problems in the LaTeX document

CheckMyTex already comes with a set of very useful tools and rules to find potential problems.

from checkmytex.finding import (
    Languagetool,
    AspellChecker,
    CheckSpell,
    UniformNpHard,
    Cleveref,
    Proselint,
    SiUnitx,
)

You can also easily create your own rule. For example, a common antipattern in my community is to exclude many lines of text by defining a \old{..}-command. Let us quickly write a rule that detects this behavior, using a simple regular expression.

Note that LatexDocument provides us with all the necessary tools to read source and compiled latex, as well as trace the problem back to its origin.

import re
from checkmytex.finding import Checker, Problem
from checkmytex import LatexDocument
import typing


class NoOld(Checker):
    def check(self, document: LatexDocument) -> typing.Iterable[Problem]:
        source = document.get_source()
        for match in re.finditer(r"\\old\{", source):
            origin = document.get_simplified_origin_of_source(
                match.start(), match.end()
            )
            context = document.get_source_context(origin)
            long_id = f"NO_OLD:{context}"
            yield Problem(
                origin,
                "Please do not use \\old{! (it confuses highlighting)",
                context=context,
                long_id=long_id,
                tool="CustomNoOld",
                rule="NO_OLD",
            )

This is all! Now you can add this rule to the DocumentAnalyzer with add_checker. You may want to copy the main.py and build yourself a custom version that directly includes this rule.

Filtering patterns of false positives

Some false positives follow some pattern. For example author names are usually not in any dictionary. The current default already tries to detect if a spelling error is actually an author name and automatically removes it. You can easily write such a filter yourself.

By default, CheckMyTex comes with the following filtering rules:

• Spelling errors in \includegraphics-paths.
• Spelling errors in labels.
• Spelling errors of words used in the bibliography. This also removes a lot of author names from the problem list.
• Spelling errors of author names before a \cite
• Problems in the whitelist.
• Ignore words used repeatedly in adjacent sentences (currently only the word "problem").
• Words with \ or $ in them. They are usually terms and not proper words.

Let us extend these rules: imagine you don't want any errors within an align-environment shown.

import re
import typing

from checkmytex.filtering import Filter
from checkmytex.finding import Problem
from checkmytex import LatexDocument


class FilterAlign(Filter):
    def __init__(self):
        self._ranges = []

    def prepare(self, document: LatexDocument):
        #  analyze which parts of the source are align-environments using a regular expression
        expr = r"\\begin\{align\}.*?\\end\{align\}"
        source = document.get_source()
        for match in re.finditer(expr, source, re.MULTILINE | re.DOTALL):
            self._ranges.append((match.start(), match.end()))

    def filter(self, problems: typing.Iterable[Problem]) -> typing.Iterable[Problem]:
        for p in problems:
            s_span = p.origin.get_source_span()
            if any(r[0] <= s_span[0] < r[1] for r in self._ranges):
                continue  # problem starts within a previous found range of an align-environment
            yield p

We can add this filter similar to a checker to the DocumentAnalyzer.

Other Languages

Other languages are partially supported: You need to create your own main-file and provide the right language codes for the different tools. An example for german can be found in german.py.

Development Status

This tool is still under development but already usable. Just expect some imperfections. Ideas are welcome.

TODOs

• Reduce double-whitespace matches. They do not matter in LaTeX. Maybe clean the detexed file instead of just disabling the corresponding rules?
• More configuration options. Currently, the best option is to simply build your own main.py

Changes

• 0.10.5: Fixing --print option.
• 0.10.4: Fixing exception when $EDITOR is not set.
• 0.10.3: Making project slightly more robust.
• 0.10.2: Making project pep compliant.
• 0.10.1: Also the interactive mode is now using rich.
• 0.10.0: Beautiful HTML-output using rich. Interactive CLI will follow soon.
• 0.9.0: Fundamental refactoring and JSON-ouput.
• 0.8.1: Fixing problem with text manipulated by commands. All found errors now should only span a single line. Solution is ugly and should be improved. For now, it is working. .