fix: accommodate math code blocks within Markdown equations

kgryte · kgryte · commit 98eee8f736f3 · 2024-11-20T01:07:04.000-08:00
diff --git a/lib/node_modules/@stdlib/_tools/remark/plugins/remark-svg-equations/lib/transformer.js b/lib/node_modules/@stdlib/_tools/remark/plugins/remark-svg-equations/lib/transformer.js
@@ -149,16 +149,66 @@ function transformer( tree, file, clbk ) {
 		parent = equations[ idx ].parent;
 		i = equations[ idx ].index;
 
-		// Case 1: insert new node between equation tags...
+		/*
+		* Case 1: insert new node between equation tags.
+		*
+		* ```markdown
+		* <!-- <equation class="equation" label="eq:triangular_root" align="center" raw="n = \frac{\sqrt{8x+1} - 1}{2}" alt="Triangular root formula."> -->
+		*
+		* <!-- </equation> -->
+		* ```
+		*/
 		if ( EQN_END.test( parent.children[ i+1 ].value ) ) {
 			debug( 'Inserting new node...' );
 			parent.children.splice( i+1, 0, newNode );
 		}
-		// Case 2: replace existing node...
+		/*
+		* Case 2: replace existing node.
+		*
+		* ```markdown
+		* <!-- <equation class="equation" label="eq:triangular_root" align="center" raw="n = \frac{\sqrt{8x+1} - 1}{2}" alt="Triangular root formula."> -->
+		*
+		* <div class="equation" align="center" data-raw-text="n = \frac{\sqrt{8x+1} - 1}{2}" data-equation="eq:triangular_root">
+    	*     <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@b295a09a80f4fd0cc84682dcda0fe3e354394c0c/lib/node_modules/@stdlib/assert/is-square-triangular-number/docs/img/equation_triangular_root.svg" alt="Triangular root formula.">
+    	*     <br>
+		* </div>
+		*
+		* <!-- </equation> -->
+		* ```
+		*/
 		else if ( EQN_END.test( parent.children[ i+2 ].value ) ) {
 			debug( 'Replacing existing node...' );
 			parent.children[ i+1 ] = newNode;
 		}
+		/*
+		* Case 3: replace existing nodes.
+		*
+		* ```markdown
+		* <!-- <equation class="equation" label="eq:triangular_root" align="center" raw="n = \frac{\sqrt{8x+1} - 1}{2}" alt="Triangular root formula."> -->
+		*
+		* \`\`\`math
+		* n = \frac{\sqrt{8x+1} - 1}{2}
+		* \`\`\`
+		*
+		* <!-- <div class="equation" align="center" data-raw-text="n = \frac{\sqrt{8x+1} - 1}{2}" data-equation="eq:triangular_root">
+    	*     <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@b295a09a80f4fd0cc84682dcda0fe3e354394c0c/lib/node_modules/@stdlib/assert/is-square-triangular-number/docs/img/equation_triangular_root.svg" alt="Triangular root formula.">
+    	*     <br>
+		* </div> -->
+		*
+		* <!-- </equation> -->
+		* ```
+		*/
+		else if ( EQN_END.test( parent.children[ i+3 ].value ) ) {
+			debug( 'Replacing existing nodes...' );
+
+			// Note: we don't splice--we simply replace--in order to avoid invalidating the indices of the equation elements in the AST. If we were to remove children, a subsequent resolved equation index would no longer be accurate...
+			parent.children[ i+1 ] = newNode;
+			parent.children[ i+1 ] = {
+				'type': 'html',
+				'value': '<!-- -->'
+			};
+		}
+		// Otherwise, an invalid node...
 		else {
 			debug( 'Invalid node: %s', parent.children[ idx ].value );
 			error = new Error( format( 'invalid node. Invalid equation comment. Ensure that the Markdown file includes both starting and ending equation comments. Node: `%s`.', parent.children[ idx ].value ) );
