feature: strict rendering, close #9

test/error.js

@@ -42,14 +42,6 @@ describe('error', function() {
         });
     });
 
-    it('should throw ParseError when filter not exist', function() {
-        return test(engine.parseAndRender('{{ a | xz }}', {}), function(err){
-            expect(err.name).to.equal('ParseError');
-            expect(err.message).to.equal('filter "xz" not found');
-            expect(err.input).to.equal('{{ a | xz }}');
-            expect(err.line).to.equal(1);
-        });
-    });
     it('should throw ParseError when tag not exist', function() {
         return test(engine.parseAndRender('{% a %}', {}), function(err){
             expect(err.name).to.equal('ParseError');

test/filter.js

@@ -14,10 +14,10 @@ describe('filter', function() {
         filter.clear();
         scope = Scope.factory();
     });
-    it('should throw when not registered', function() {
-        expect(function() {
-            filter.construct('foo');
-        }).to.throw(/filter "foo" not found/);
+    it('should return undefined when not registered', function() {
+        var result = filter.construct('foo');
+        expect(result.name).to.equal('foo');
+        expect(result.error).to.be.an('Error');
     });
 
     it('should parse argument syntax', function(){

test/liquid.js

@@ -37,6 +37,16 @@ describe('liquid', function() {
     it('should output undefined to empty', function() {
         return engine.parseAndRender('foo{{zzz}}bar', ctx).should.eventually.equal('foobar');
     });
+    it('should render as null when filter undefined', function() {
+        return engine.parseAndRender('{{arr | filter1}}', ctx).should.eventually.equal('');
+    });
+    it('should throw upon undefined filter when strict_filters set', function() {
+        var opts = {
+            strict_filters: true
+        };
+        return expect(engine.parseAndRender('{{arr | filter1}}', ctx, opts)).to
+            .be.rejectedWith(/undefined filter: filter1/);
+    });
     it('should parse html', function() {
         (function() {
             engine.parse('{{obj}}');