Add explicit tests to spec/ast.js for using whitespace control

spec/ast.js

@@ -123,6 +123,40 @@ describe('ast', function() {
      });
   });
 
+  describe('whitespace control', function() {
+    describe('parse', function() {
+      it('mustache', function() {
+        let ast = Handlebars.parse('  {{~comment~}} ');
+
+        equals(ast.body[0].value, '');
+        equals(ast.body[2].value, '');
+      });
+
+      it('block statements', function() {
+        var ast = Handlebars.parse(' {{# comment~}} \nfoo\n {{~/comment}}');
+
+        equals(ast.body[0].value, '');
+        equals(ast.body[1].program.body[0].value, 'foo');
+      });
+    });
+
+    describe('parseWithoutProcessing', function() {
+      it('mustache', function() {
+        let ast = Handlebars.parseWithoutProcessing('  {{~comment~}} ');
+
+        equals(ast.body[0].value, '  ');
+        equals(ast.body[2].value, ' ');
+      });
+
+      it('block statements', function() {
+        var ast = Handlebars.parseWithoutProcessing(' {{# comment~}} \nfoo\n {{~/comment}}');
+
+        equals(ast.body[0].value, ' ');
+        equals(ast.body[1].program.body[0].value, ' \nfoo\n ');
+      });
+    });
+  });
+
   describe('standalone flags', function() {
     describe('mustache', function() {
       it('does not mark mustaches as standalone', function() {