1 files changed, 101 insertions, 0 deletions
diff --git a/tools/eslint/lib/rules/no-multi-spaces.js b/tools/eslint/lib/rules/no-multi-spaces.js
new file mode 100644
index 0000000000..9e247c1533
--- /dev/null
+++ b/tools/eslint/lib/rules/no-multi-spaces.js
@@ -0,0 +1,101 @@
+/**
+ * @fileoverview Disallow use of multiple spaces.
+ * @author Nicholas C. Zakas
+ * @copyright 2015 Brandon Mills. All rights reserved.
+ * @copyright 2015 Nicholas C. Zakas. All rights reserved.
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = function(context) {
+
+    // the index of the last comment that was checked
+    var exceptions = { "Property": true },
+        hasExceptions = true,
+        options = context.options[0],
+        lastCommentIndex = 0;
+
+    if (options && options.exceptions) {
+        Object.keys(options.exceptions).forEach(function (key) {
+            if (options.exceptions[key]) {
+                exceptions[key] = true;
+            } else {
+                delete exceptions[key];
+            }
+        });
+        hasExceptions = Object.keys(exceptions).length > 0;
+    }
+
+    /**
+     * Determines if a given source index is in a comment or not by checking
+     * the index against the comment range. Since the check goes straight
+     * through the file, once an index is passed a certain comment, we can
+     * go to the next comment to check that.
+     * @param {int} index The source index to check.
+     * @param {ASTNode[]} comments An array of comment nodes.
+     * @returns {boolean} True if the index is within a comment, false if not.
+     * @private
+     */
+    function isIndexInComment(index, comments) {
+
+        var comment;
+
+        while (lastCommentIndex < comments.length) {
+
+            comment = comments[lastCommentIndex];
+
+            if (comment.range[0] <= index && index < comment.range[1]) {
+                return true;
+            } else if (index > comment.range[1]) {
+                lastCommentIndex++;
+            } else {
+                break;
+            }
+
+        }
+
+        return false;
+    }
+
+    //--------------------------------------------------------------------------
+    // Public
+    //--------------------------------------------------------------------------
+
+    return {
+        "Program": function() {
+
+            var source = context.getSource(),
+                allComments = context.getAllComments(),
+                pattern = /[^\n\r\u2028\u2029 ] {2,}/g,  // note: repeating space
+                token,
+                parent;
+
+            while (pattern.test(source)) {
+
+                // do not flag anything inside of comments
+                if (!isIndexInComment(pattern.lastIndex, allComments)) {
+
+                    token = context.getTokenByRangeStart(pattern.lastIndex);
+
+                    if (token) {
+                        if (hasExceptions) {
+                            parent = context.getNodeByRangeIndex(pattern.lastIndex - 1);
+                        }
+
+                        if (!parent || !exceptions[parent.type]) {
+                            context.report(token, token.loc.start,
+                                "Multiple spaces found before '{{value}}'.",
+                                { value: token.value });
+                        }
+                    }
+
+                }
+            }
+        }
+    };
+
+};