Update MD037/no-space-in-emphasis to ignore emphasis markers in link text (fixes #280).

helpers/helpers.js

@@ -28,8 +28,8 @@ module.exports.orderedListItemMarkerRe = /^[\s>]*0*(\d+)[.)]/;
 // Regular expression for all instances of emphasis markers
 const emphasisMarkersRe = /[_*]/g;
 
-// Regular expression for links
+// Regular expression for inline links and shortcut reference links
-const linkRe = /\[(?:[^\]]|\[[^\]]*\])*\]\(\S*\)/g;
+const linkRe = /\[(?:[^[\]]|\[[^\]]*\])*\](?:\(\S*\))?/g;
 
 // readFile options for reading with the UTF-8 encoding
 module.exports.utf8Encoding = { "encoding": "utf8" };

lib/md037.js

@@ -129,7 +129,7 @@ module.exports = {
             // Back up one character so RegExp has a chance to match the
             // next marker (ex: "**star**_underscore_")
             emphasisRe.lastIndex--;
-          } else {
+          } else if (emphasisRe.lastIndex > 1) {
             // Back up one character so RegExp has a chance to match the
             // mis-matched marker (ex: "*text_*")
             emphasisRe.lastIndex--;

test/spaces_inside_emphasis_markers.md

@@ -254,3 +254,46 @@ text _underscore_**star** text _underscore_**star** text
 `****** text ******`
 
 `******* text *******`
+
+under_score
+_underscore_
+
+st*ar
+*star*
+
+under_score
+*star*
+
+st*ar
+_underscore_
+
+*star*
+_underscore_
+
+_underscore_
+*star*
+
+_underscore
+_*star*
+
+*star
+*_underscore_
+
+[reference_link]
+_first_ and _second_
+
+[reference_link]
+*first* and *second*
+
+[reference*link]
+_first_ and _second_
+
+[reference*link]
+*first* and *second*
+
+text [reference_link] under _ score text
+
+text [reference*link] star * star text
+
+[reference_link]: https://example.com
+[reference*link]: https://example.com