Update MD037/no-space-in-emphasis to ignore emphasis markers in link text/destination (refs #286).

helpers/helpers.js

@@ -28,6 +28,9 @@ module.exports.orderedListItemMarkerRe = /^[\s>]*0*(\d+)[.)]/;
 // Regular expression for emphasis markers
 const emphasisMarkersRe = /[_*]+/g;
 
+// Regular expression for links
+const linkRe = /\[(?:[^\]]|\[[^\]]*\])*\]\(\S*\)/g;
+
 // readFile options for reading with the UTF-8 encoding
 module.exports.utf8Encoding = { "encoding": "utf8" };
 
@@ -494,14 +497,15 @@ module.exports.frontMatterHasTitle =
   };
 
 /**
- * Returns a list of emphasis markers in code spans.
+ * Returns a list of emphasis markers in code spans and links.
  *
  * @param {Object} params RuleParams instance.
  * @returns {number[][]} List of markers.
  */
-function emphasisMarkersInCodeSpans(params) {
+function emphasisMarkersInContent(params) {
   const { lines } = params;
   const byLine = new Array(lines.length);
+  // Search code spans
   filterTokens(params, "inline", (token) => {
     const { children, lineNumber, map } = token;
     if (children.some((child) => child.type === "code_inline")) {
@@ -524,9 +528,21 @@ function emphasisMarkersInCodeSpans(params) {
       );
     }
   });
+  // Search links
+  lines.forEach((tokenLine, tokenLineIndex) => {
+    let linkMatch = null;
+    while ((linkMatch = linkRe.exec(tokenLine))) {
+      let markerMatch = null;
+      while ((markerMatch = emphasisMarkersRe.exec(linkMatch[0]))) {
+        const inLine = byLine[tokenLineIndex] || [];
+        inLine.push(linkMatch.index + markerMatch.index);
+        byLine[tokenLineIndex] = inLine;
+      }
+    }
+  });
   return byLine;
 }
-module.exports.emphasisMarkersInCodeSpans = emphasisMarkersInCodeSpans;
+module.exports.emphasisMarkersInContent = emphasisMarkersInContent;
 
 /**
  * Gets the most common line ending, falling back to the platform default.

lib/md037.js

@@ -2,8 +2,8 @@
 
 "use strict";
 
-const { addErrorContext, emphasisMarkersInCodeSpans, forEachLine,
-  includesSorted, isBlankLine } = require("../helpers");
+const { addErrorContext, emphasisMarkersInContent, forEachLine, isBlankLine } =
+  require("../helpers");
 const { lineMetadata } = require("./cache");
 
 const emphasisRe = /(^|[^\\])(?:(\*\*?\*?)|(__?_?))/g;
@@ -66,7 +66,7 @@ module.exports = {
       return null;
     }
     // Initialize
-    const ignoreMarkersByLine = emphasisMarkersInCodeSpans(params);
+    const ignoreMarkersByLine = emphasisMarkersInContent(params);
     resetRunTracking();
     forEachLine(
       lineMetadata(),
@@ -89,8 +89,8 @@ module.exports = {
         while ((match = emphasisRe.exec(line))) {
           const ignoreMarkersForLine = ignoreMarkersByLine[lineIndex] || [];
           const matchIndex = match.index + match[1].length;
-          if (includesSorted(ignoreMarkersForLine, matchIndex)) {
-            // Ignore emphasis markers inside code spans
+          if (ignoreMarkersForLine.includes(matchIndex)) {
+            // Ignore emphasis markers inside code spans and links
             continue;
           }
           const matchLength = match[0].length - match[1].length;

test/spaces_inside_emphasis_markers.md

@@ -174,3 +174,17 @@ Mixed `code*span` scenarios are *also* okay.
 Mixed `code*span` scenarios are _also_ okay.
 
 Mixed `code_span` scenarios are *also* okay.
+
+[Link](under_score) followed by _underscore_
+
+[Link](un_der_score) followed by _underscore_
+
+[Link](un_der_sco_re) followed by _underscore_
+
+[Link](star*star) followed by *star*
+
+* [Link](star*star) followed by *star*
+
+Text [Link](under_score) text _underscore_ text [Link](st*ar) text *star* text
+
+[Link [link] link](under_score) followed by _underscore_