maximumLineLength: some nodes might contain null values

Fixes #2107

Author: markelog

lib/rules/maximum-line-length.js

@@ -135,6 +135,12 @@ module.exports.prototype = {
         lines = lines.slice();
 
         var removeLoc = function(tokenOrNode) {
+
+            // Just in case (See #2107 for example)
+            if (!tokenOrNode) {
+                return;
+            }
+
             for (var i = tokenOrNode.loc.start.line; i <= tokenOrNode.loc.end.line; i++) {
                 lines[i - 1] = '';
             }
@@ -156,6 +162,9 @@ module.exports.prototype = {
 
         if (this._allowFunctionSignature) {
             file.iterateNodesByType('FunctionDeclaration', function(node) {
+
+                // Need to remove the first line, because we can't be sure there's any id or params
+                lines[node.loc.start.line - 1] = '';
                 removeLoc(node.id);
                 node.params.forEach(removeLoc);
             });
@@ -168,9 +177,7 @@ module.exports.prototype = {
 
                 // Need to remove the first line, because we can't be sure there's any id or params
                 lines[node.loc.start.line - 1] = '';
-                if (node.id) {
-                    removeLoc(node.id);
-                }
+                removeLoc(node.id);
                 node.params.forEach(removeLoc);
             });
         }

test/specs/rules/maximum-line-length.js

@@ -242,6 +242,14 @@ describe('rules/maximum-line-length', function() {
             var code = '// function myCoolFunction(argument) { }';
             expect(checker.checkString(code)).to.have.one.validation.error.from('maximumLineLength');
         });
+
+        it('should not break on export default function', function() {
+            expect(checker.checkString('export default function() {}')).to.have.no.errors();
+        });
+
+        it('should not break on export default function with params', function() {
+            expect(checker.checkString('export default function(s) {}')).to.have.no.errors();
+        });
     });
 
     describe('allExcept["require"] option', function() {