requireCurlyBraces: use tokenAssert methods

- cleanup: make similar to disallowCurlyBraces

Author: hzoo

lib/rules/require-curly-braces.js

@@ -67,17 +67,11 @@ module.exports.prototype = {
 
     check: function(file, errors) {
 
-        function addError(typeString, node) {
-            var entity = node;
-
-            if (typeString === 'Else') {
-                entity = file.findPrevToken(
-                    file.getTokenByRangeStart(node.alternate.range[0]),
-                    'Keyword',
-                    'else'
-                );
-            }
+        function isNotABlockStatement(node) {
+            return node && node.type !== 'BlockStatement';
+        }
 
+        function addError(typeString, entity) {
             errors.add(
                 typeString + ' statement without curly braces',
                 entity.loc.start.line,
@@ -87,7 +81,7 @@ module.exports.prototype = {
 
         function checkBody(type, typeString) {
             file.iterateNodesByType(type, function(node) {
-                if (node.body.type !== 'BlockStatement') {
+                if (isNotABlockStatement(node.body)) {
                     addError(typeString, node);
                 }
             });
@@ -97,14 +91,12 @@ module.exports.prototype = {
 
         if (typeIndex['if'] || typeIndex['else']) {
             file.iterateNodesByType('IfStatement', function(node) {
-                if (typeIndex.if && node.consequent.type !== 'BlockStatement') {
+                if (typeIndex['if'] && isNotABlockStatement(node.consequent)) {
                     addError('If', node);
                 }
-                if (typeIndex['else'] && node.alternate &&
-                    node.alternate.type !== 'BlockStatement' &&
-                    node.alternate.type !== 'IfStatement'
-                ) {
-                    addError('Else', node);
+                if (typeIndex['else'] && isNotABlockStatement(node.alternate) &&
+                    node.alternate.type !== 'IfStatement') {
+                    addError('Else', file.getPrevToken(file.getFirstNodeToken(node.alternate)));
                 }
             });
         }

test/rules/require-curly-braces.js

@@ -153,4 +153,9 @@ describe('rules/require-curly-braces', function() {
         assert(error.line === 4);
         assert(error.column === 12);
     });
+
+    it('should not report missing `else` braces for `else if`', function() {
+        checker.configure({ requireCurlyBraces: ['else'] });
+        assert(checker.checkString('if (x) { x++; } else if (x) { x++; }').isEmpty());
+    });
 });