Utils: escaping function should’t render undefined/Null/NaN

Motivation: for safety reasons I decided to change regular cast to string. In
frontend we need only useful values such as Strings and Numbers. All undefined,
NaN, Null and [Object object] values is useless and are a mistake in HTML.

lib/bemxjst/utils.js

@@ -7,6 +7,12 @@ var singleQuot = ''';
 var matchXmlRegExp = /[&<>]/;
 
 exports.xmlEscape = function(string) {
+  if (typeof string === 'undefined' ||
+     string === null ||
+     (typeof string === 'number' && isNaN(string))
+     )
+    return '';
+
   var str = '' + string;
   var match = matchXmlRegExp.exec(str);
 
@@ -48,6 +54,11 @@ exports.xmlEscape = function(string) {
 var matchAttrRegExp = /["&]/;
 
 exports.attrEscape = function(string) {
+  if (typeof string === 'undefined' ||
+     string === null ||
+     (typeof string === 'number' && isNaN(string)))
+    return '';
+
   var str = '' + string;
   var match = matchAttrRegExp.exec(str);
 
@@ -86,6 +97,11 @@ exports.attrEscape = function(string) {
 var matchJsAttrRegExp = /['&]/;
 
 exports.jsAttrEscape = function(string) {
+  if (typeof string === 'undefined' ||
+     string === null ||
+     (typeof string === 'number' && isNaN(string)))
+    return '';
+
   var str = '' + string;
   var match = matchJsAttrRegExp.exec(str);
 

test/bemcontext-attrescape-test.js

@@ -1,4 +1,5 @@
 var fixtures = require('./fixtures')('bemhtml');
+var compile = fixtures.compile;
 var test = fixtures.test;
 
 describe('BEMContext this.attrEscape(str)', function() {
@@ -11,4 +12,67 @@ describe('BEMContext this.attrEscape(str)', function() {
     { block: 'button' },
     '<b id=&quot;a&quot; class=&quot;bem&quot;>a&amp;b&amp;c</b>');
   });
+
+  describe('Type of argument', function() {
+    var bemhtml;
+
+    before(function() {
+      bemhtml = compile(function() {
+        block('b').def()(function(n, ctx) {
+          return n.attrEscape(ctx.val);
+        });
+      });
+    });
+
+    it('should return \'\' for undefined', function() {
+      bemhtml.apply({ block: 'b', val: undefined }).should.equal('');
+    });
+
+    it('should return \'\' for null', function() {
+      bemhtml.apply({ block: 'b', val: null }).should.equal('');
+    });
+
+    it('should return String for zero', function() {
+      bemhtml.apply({ block: 'b', val: 0 }).should.equal('0');
+    });
+
+    it('should return String for Number', function() {
+      bemhtml.apply({ block: 'b', val: 42 }).should.equal('42');
+    });
+
+    it('should return \'\' for NaN', function() {
+      bemhtml.apply({ block: 'b', val: NaN }).should.equal('');
+    });
+
+    it('should return String for String', function() {
+      bemhtml.apply({ block: 'b', val: '' }).should.equal('');
+    });
+
+    it('should return String for String', function() {
+      bemhtml.apply({ block: 'b', val: 'test' }).should.equal('test');
+    });
+
+    it('should return String for Boolean', function() {
+      bemhtml.apply({ block: 'b', val: false }).should.equal('false');
+    });
+
+    it('should return String for Array', function() {
+      bemhtml.apply({ block: 'b', val: [] }).should.equal('');
+    });
+
+    it('should return String for Array', function() {
+      bemhtml.apply({ block: 'b', val: [ 'a', 'b' ] }).should.equal('a,b');
+    });
+
+    it('should return \'\' for Object', function() {
+      bemhtml.apply({ block: 'b', val: {
+        toString: function() { return ''; }
+      } }).should.equal('');
+    });
+
+    it('should return \'\' for Function', function() {
+      bemhtml.apply({ block: 'b', val: function() {} })
+        .should.equal('function () {}');
+    });
+  });
 });

test/bemcontext-jsattrescape-test.js

@@ -12,4 +12,67 @@ describe('BEMContext this.jsAttrEscape(str)', function() {
       .should.equal('<b foo="a">&#39;&amp;&#39;</b><b bar="b">&#39;&amp;' +
                     '&#39;</b>');
   });
+
+  describe('Type of argument', function() {
+    var bemhtml;
+
+    before(function() {
+      bemhtml = compile(function() {
+        block('b').def()(function(n, ctx) {
+          return n.jsAttrEscape(ctx.val);
+        });
+      });
+    });
+
+    it('should return \'\' for undefined', function() {
+      bemhtml.apply({ block: 'b', val: undefined }).should.equal('');
+    });
+
+    it('should return \'\' for null', function() {
+      bemhtml.apply({ block: 'b', val: null }).should.equal('');
+    });
+
+    it('should return String for zero', function() {
+      bemhtml.apply({ block: 'b', val: 0 }).should.equal('0');
+    });
+
+    it('should return String for Number', function() {
+      bemhtml.apply({ block: 'b', val: 42 }).should.equal('42');
+    });
+
+    it('should return \'\' for NaN', function() {
+      bemhtml.apply({ block: 'b', val: NaN }).should.equal('');
+    });
+
+    it('should return String for String', function() {
+      bemhtml.apply({ block: 'b', val: '' }).should.equal('');
+    });
+
+    it('should return String for String', function() {
+      bemhtml.apply({ block: 'b', val: 'test' }).should.equal('test');
+    });
+
+    it('should return String for Boolean', function() {
+      bemhtml.apply({ block: 'b', val: false }).should.equal('false');
+    });
+
+    it('should return String for Array', function() {
+      bemhtml.apply({ block: 'b', val: [] }).should.equal('');
+    });
+
+    it('should return String for Array', function() {
+      bemhtml.apply({ block: 'b', val: [ 'a', 'b' ] }).should.equal('a,b');
+    });
+
+    it('should return \'\' for Object', function() {
+      bemhtml.apply({ block: 'b', val: {
+        toString: function() { return ''; }
+      } }).should.equal('');
+    });
+
+    it('should return \'\' for Function', function() {
+      bemhtml.apply({ block: 'b', val: function() {} })
+        .should.equal('function () {}');
+    });
+  });
 });

test/bemcontext-xmlescape-test.js

@@ -1,4 +1,5 @@
 var fixtures = require('./fixtures')('bemhtml');
+var compile = fixtures.compile;
 var test = fixtures.test;
 
 describe('BEMContext this.xmlEscape()', function() {
@@ -11,4 +12,67 @@ describe('BEMContext this.xmlEscape()', function() {
     { block: 'button' },
     '<b>&</b>');
   });
+
+  describe('Type of argument', function() {
+    var bemhtml;
+
+    before(function() {
+      bemhtml = compile(function() {
+        block('b').def()(function(n, ctx) {
+          return n.xmlEscape(ctx.val);
+        });
+      });
+    });
+
+    it('should return \'\' for undefined', function() {
+      bemhtml.apply({ block: 'b', val: undefined }).should.equal('');
+    });
+
+    it('should return \'\' for null', function() {
+      bemhtml.apply({ block: 'b', val: null }).should.equal('');
+    });
+
+    it('should return String for zero', function() {
+      bemhtml.apply({ block: 'b', val: 0 }).should.equal('0');
+    });
+
+    it('should return String for Number', function() {
+      bemhtml.apply({ block: 'b', val: 42 }).should.equal('42');
+    });
+
+    it('should return \'\' for NaN', function() {
+      bemhtml.apply({ block: 'b', val: NaN }).should.equal('');
+    });
+
+    it('should return String for String', function() {
+      bemhtml.apply({ block: 'b', val: '' }).should.equal('');
+    });
+
+    it('should return String for String', function() {
+      bemhtml.apply({ block: 'b', val: 'test' }).should.equal('test');
+    });
+
+    it('should return String for Boolean', function() {
+      bemhtml.apply({ block: 'b', val: false }).should.equal('false');
+    });
+
+    it('should return String for Array', function() {
+      bemhtml.apply({ block: 'b', val: [] }).should.equal('');
+    });
+
+    it('should return String for Array', function() {
+      bemhtml.apply({ block: 'b', val: [ 'a', 'b' ] }).should.equal('a,b');
+    });
+
+    it('should return \'\' for Object', function() {
+      bemhtml.apply({ block: 'b', val: {
+        toString: function() { return ''; }
+      } }).should.equal('');
+    });
+
+    it('should return \'\' for Function', function() {
+      bemhtml.apply({ block: 'b', val: function() {} })
+        .should.equal('function () {}');
+    });
+  });
 });