LaTeX/Math

Overview

Inline and block LaTeX math rendering in the editor. Delimiter math (003-inline-latex-equations): $...$ (inline) and $$...$$ (block) are detected, rendered with MathJax to SVG, and displayed via decorations. Code-block math (004-code-block-math-environments): fenced blocks with math, latex, or tex language tags are rendered as display math over the whole block, with height from body line count. Raw LaTeX is revealed when the cursor or selection is inside a math region. Toggle via markdownInlineEditor.math.enabled.

Implementation

• Delimiter math: Detect $...$ and $$...$$, render to SVG, apply decorations; skip inside non-math fenced blocks.
• Code-block math: Detect ```math, ```latex, ```tex; emit whole-block range and body line count; render body as display math; reserve height = (numLines + 2) × line height so content does not overlap following lines.
• Uses MathJax (mathjax-full); no line-count limit.

Acceptance Criteria

Inline Math

Feature: Inline math formatting

  Scenario: Basic inline math
    When I type $E = mc^2$
    Then the math is detected
    And the formula is rendered inline

  Scenario: Inline math in paragraph
    When I type "The equation $x = y$ is true"
    Then the math is detected
    And surrounding text is unaffected

Block Math (Delimiters)

Feature: Block math formatting

  Scenario: Basic block math
    When I type $$
    And I type \int_0^\infty e^{-x^2} dx
    And I type $$
    Then the math is detected
    And the formula is rendered as block

  Scenario: Multi-line block math
    When I type $$
    And I type \begin{align}
    And I type x &= y
    And I type \end{align}
    And I type $$
    Then the math is detected correctly

Code-Block Math

Feature: Code-block math

  Scenario: Math fence renders as display math
    When I type ```math
    And I type \sum_{n=1}^{\infty} \frac{1}{n^2} = \frac{\pi^2}{6}
    And I type ```
    Then the block is rendered as display math
    And the following line is not overlapped

  Scenario: latex and tex fences
    When I type ```latex or ```tex with LaTeX body
    Then the block is rendered like ```math

Edge Cases

Feature: Math edge cases

  Scenario: Dollar sign in text
    When I type "Price is \$10"
    Then it is not treated as math
    And the dollar sign is preserved

  Scenario: Escaped dollar
    When I type \$10
    Then it is not treated as math

  Scenario: Dollars in non-math code block
    When I type ```js and $x$ inside
    Then no math region is emitted for the code block

Reveal Raw Markdown

Feature: Reveal math

  Scenario: Reveal on select
    Given $E = mc^2$ is in my file
    When I select the math
    Then the raw markdown is shown
    When I deselect
    Then the math is rendered again

Notes

• 003-inline-latex-equations: Delimiter math ($...$, $$...$$); specs in specs/003-inline-latex-equations/.
• 004-code-block-math-environments: Fenced math/latex/tex blocks; specs in specs/004-code-block-math-environments/; height and range follow mermaid-style behavior.
• Known issue: Theme-appropriate font color for rendered math may need follow-up.
• Essential for academic/technical users.

Examples

• Inline: $E = mc^2$ → Rendered formula inline
• Block (delimiters): $$\int_0^\infty e^{-x^2} dx = \frac{\sqrt{\pi}}{2}$$ → Rendered as block
• Block (fence): ```math with \sum_{n=1}^{\infty} \frac{1}{n^2} = \frac{\pi^2}{6} → Display math over whole block, no overlap with next line