fix(#72): differentiate math and escaped brackets

[KyleKing]

No description provided.

[coderabbitai]

Walkthrough

The pull request updates the Arithmatex plugin to detect and ignore escaped bracket sequences (\[...\]) so they are not parsed as math. It adds a regex and helper to identify escaped brackets, wraps two texmath block rules with a conditional wrapper to bypass math parsing when escaped brackets are present, includes imports and documentation updates, and expands tests covering escaped-bracket edge cases.

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Reviewing files that changed from the base of the PR and between befce35 and a37c660.

📒 Files selected for processing (2)

• mdformat_mkdocs/mdit_plugins/_pymd_arithmatex.py
• tests/format/fixtures/pymd_arithmatex_edge_cases.md

🔇 Additional comments (6)

tests/format/fixtures/pymd_arithmatex_edge_cases.md (1)

12-66: LGTM - Comprehensive test coverage for escaped bracket scenarios.

The new test cases properly cover the key edge cases: escaped brackets in lists, multi-line math blocks vs single-line escaped brackets, and escaped brackets with trailing content.

mdformat_mkdocs/mdit_plugins/_pymd_arithmatex.py (5)

20-32: LGTM - Imports are appropriate.

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44-47: Regex pattern correctly identifies escaped brackets.

The pattern properly detects single-line \[...\] with non-whitespace immediately after, distinguishing escaped brackets from valid math blocks.

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52-64: Logic is sound with proper bounds checking.

The function correctly:

1. Guards against out-of-bounds access
2. Only processes lines starting with \[
3. Uses regex to distinguish escaped brackets from math blocks

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87-95: Wrapper pattern is clean and correct.

The closure captures the original function and conditionally bypasses math parsing for escaped brackets.

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97-118: Runtime validation properly guards against configuration changes.

The wrapped_count check with a clear error message addresses the fragility of relying on plugin registration order. This ensures the fix fails fast if the underlying mdit-py-plugins API changes.

Note: The private __rules__ access is a known limitation documented in past reviews - the public Ruler API cannot distinguish between rules with the same name.

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[coderabbitai]

Actionable comments posted: 1

Fix all issues with AI Agents 🤖

In @mdformat_mkdocs/mdit_plugins/_pymd_arithmatex.py:
- Around line 75-97: The rule-wrapping loop that modifies
md.block.ruler.__rules__ is fragile; add runtime validation to ensure the
intended texmath rules were actually wrapped. In the loop that iterates over
md.block.ruler.__rules__ (the block that references found_first_math_block,
rule.name == "math_block", rule.name == "math_block_eqno", and uses
make_wrapper(rule.fn)), increment a wrapped_count each time you replace a
rule.fn with make_wrapper and after the loop assert wrapped_count == 2 (or raise
a RuntimeError with a clear message if less), so that
make_wrapper/_is_escaped_bracket logic only proceeds when both the second
"math_block" and "math_block_eqno" have been found and wrapped.

📜 Review details

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 5aa0b3c and befce35.

📒 Files selected for processing (1)

• mdformat_mkdocs/mdit_plugins/_pymd_arithmatex.py

🔇 Additional comments (4)

mdformat_mkdocs/mdit_plugins/_pymd_arithmatex.py (4)

20-20: LGTM: Imports are necessary and correctly placed.

The re module and StateBlock type are both used appropriately in the new code.

Also applies to: 29-29

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47-57: LGTM: Function logic is sound.

The early return for non-\[ lines is an efficient optimization. The function inherits any limitations from _ESCAPED_BRACKET_RE (see previous comment).

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65-65: LGTM: Documentation update is clear and appropriate.

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41-44: Pattern is intentionally restrictive and working as designed.

The regex correctly identifies escaped bracket notation (like \[label\]: value) that should NOT be processed as math blocks. Cases like \[content\] at line end or followed by whitespace properly fall through to the texmath parser, which is the intended behavior. The (\S) requirement after \] specifically catches the escaped bracket pattern to fix issue #72.

[Copilot]

Pull request overview

This PR fixes issue #72 by adding logic to differentiate between LaTeX math expressions using \[...\] syntax and escaped bracket patterns like \[test\]: value that should not be treated as math.

Key changes:

• Adds a regex pattern and helper function to detect escaped bracket syntax on a single line with non-whitespace content immediately following the closing bracket
• Wraps the texmath plugin's block rules to filter out escaped bracket patterns before processing math blocks

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