Compass 2934 don not autocomplete in comments

.eslintrc

@@ -1,6 +1,6 @@
 {
   "ecmaFeatures": {
-    "blockBindings": true,
+    "blockBindings": true
   },
   "globals": {
     "expect": true,

lib/stage-autocompleter.js

@@ -36,6 +36,43 @@ const DOLLAR = '$';
  */
 const BASE_COMPLETIONS = EXPRESSION_OPERATORS.concat(CONVERSION_OPERATORS.concat(BSON_TYPES));
 
+
+/**
+ * Multi-line comment regex
+ */
+const MULTI_LINE_COMMENT_RE = /\/(\*)[^*]*\*+(?:[^*\/][^*]*\*+)*\//.source;
+
+/**
+ * Single-line comment regex
+ */
+const SINGLE_LINE_COMMENT_RE = /\/(\/)[^\n]*$/.source;
+
+/**
+ * String regex
+ */
+const STRING_RE = /"(?:[^"\\]*|\\[\S\s])*"|'(?:[^'\\]*|\\[\S\s])*'/.source;
+
+/**
+ * Division operator regex
+ */
+const DIVISION_OPERATOR_RE = /(?:[$\w\)\]]|\+\+|--)\s*\/(?![*\/])/.source;
+
+/**
+ * Regular expression regex
+ */
+const REGEX_RE = /\/(?=[^*\/])[^[/\\]*(?:(?:\[(?:\\.|[^\]\\]*)*\]|\\.)[^[/\\]*)*?\/[gim]*/.source;
+
+/**
+ * Find slashes regex
+ */
+const FIND_COMMENTS_RE = new RegExp([
+  MULTI_LINE_COMMENT_RE,
+  SINGLE_LINE_COMMENT_RE,
+  STRING_RE,
+  DIVISION_OPERATOR_RE,
+  REGEX_RE
+].join('|'), 'gm');
+
 /**
  * Adds autocomplete suggestions based on the aggregation pipeline
  * operators.
@@ -124,6 +161,20 @@ class StageAutoCompleter {
   getCompletions(editor, session, position, prefix, done) {
     // Empty prefixes do not return results.
     if (prefix === '') return done(null, []);
+
+    // Comments block do not return results.
+    const activePosition = session.getDocument().positionToIndex(position, 0);
+    let isComment = false;
+    session.getValue().replace(FIND_COMMENTS_RE, (match, mlc, slc, start) => {
+      if ((mlc || slc) && start < activePosition && activePosition <= (start + match.length)) {
+        isComment = true;
+      }
+      return match;
+    });
+    if (isComment === true) {
+      return done(null, []);
+    }
+
     // If the current token is a string with single or double quotes, then
     // we want to use the local text completer instead of suggesting operators.
     // This is so we can suggest user variable names inside the pipeline that they
@@ -141,7 +192,7 @@ class StageAutoCompleter {
       this.queryAutoCompleter.getCompletions(editor, session, position, prefix, done);
     } else {
       const expressions = BASE_COMPLETIONS.concat(this.accumulators()).concat(this.fields);
-      done(null, filter(this.version, expressions, prefix));
+      return done(null, filter(this.version, expressions, prefix));
     }
   }
 }