Add inline math filter

[P-SiZK]

What

Add support for a new inline math syntax: $`...`$.
This allows writing inline math without escaping, avoiding conflicts with Markdown syntax.

This new syntax follows the inline math syntax used on GitHub (reference) and GitLab (reference).

How

• Added new filter: Created Qiita::Markdown::Filters::InlineMath class
  • Detects $<code>...</code>$ patterns
  • Converts <code> tags to <span>$formula$</span>
  • Implemented validation logic to avoid conflicts with $$ (block math format)

[gemini-code-assist]

Summary of Changes

Hello @P-SiZK, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request enhances the Qiita Markdown parser by adding a new inline math feature. It allows users to embed mathematical formulas directly within text using a clear $...$ syntax, which is then transformed into a displayable HTML span. This change improves the readability and ease of writing math in Markdown by eliminating the need for complex escaping, while also ensuring compatibility with existing block math conventions.

Highlights

• New Inline Math Format: Introduces support for a new inline math format using $...$ syntax, allowing mathematical expressions to be written without requiring character escaping.
• Conflict Avoidance: The new format is designed to avoid conflicts with standard Markdown syntax, specifically differentiating from block math ($$).
• New Filter Implementation: A new filter, Qiita::Markdown::Filters::InlineMath, has been added to detect and process the new inline math patterns.
• HTML Transformation: The filter converts detected <code> tags within the new inline math format into <span>$formula$</span> for proper rendering.

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[Copilot]

Pull Request Overview

Adds support for a new inline math format $<code>...</code>$ to the Qiita Markdown processor. This allows writing inline math without escaping characters, avoiding conflicts with standard Markdown syntax while preventing conflicts with existing block math format ($$).

• Created InlineMath filter to detect and convert the new format
• Integrated the filter into the processing pipeline
• Added comprehensive test coverage for various scenarios

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
lib/qiita/markdown/filters/inline_math.rb	New filter implementation that converts $<code>...</code>$ patterns to <span>$formula$</span>
lib/qiita/markdown/processor.rb	Adds the InlineMath filter to the default filter pipeline
lib/qiita/markdown.rb	Includes the new filter module in the main require statements
spec/qiita/markdown/filters/inline_math_spec.rb	Test suite covering various inline math scenarios including edge cases

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[gemini-code-assist]

Code Review

This pull request introduces a new filter for inline math, which is a great addition. The implementation is on the right track. I've identified a couple of areas for improvement. The logic for detecting the $ delimiters could be more robust to handle edge cases like $$$. I've suggested a way to fix this using a regular expression. I also noticed a small opportunity to refactor the code to avoid redundancy. Finally, I've recommended adding more test cases to cover these edge cases and ensure the filter is solid. Overall, good work!

[ohakutsu]

LGTM!