Make sure there's a token after the combinator.

Author: chriseppstein

src/__tests__/combinators.js

@@ -124,6 +124,12 @@ test('trailing combinator & spaces', 'p +        ', (t, tree) => {
     t.deepEqual(tree.nodes[0].nodes[0].value, 'p', 'should be a paragraph');
     t.deepEqual(tree.nodes[0].nodes[1].value, '+', 'should have a combinator');
 });
+
+test('trailing sibling combinator', 'p ~', (t, tree) => {
+    t.deepEqual(tree.nodes[0].nodes[0].value, 'p', 'should be a paragraph');
+    t.deepEqual(tree.nodes[0].nodes[1].value, '~', 'should have a combinator');
+});
+
 test('ending in comment has no trailing combinator', ".bar /* comment 3 */", (t, tree) => {
     let nodeTypes = tree.nodes[0].map(n => n.type);
     t.deepEqual(nodeTypes, ["class"]);

src/parser.js

@@ -121,7 +121,6 @@ export default class Parser {
         this.root.append(selector);
         this.current = selector;
 
-
         this.loop();
     }
 
@@ -578,7 +577,7 @@ export default class Parser {
             });
         }
 
-        if (this.currToken[TOKEN.TYPE] === tokens.space) {
+        if (this.currToken && this.currToken[TOKEN.TYPE] === tokens.space) {
             node.spaces.after = this.optionalSpace(this.content());
             this.position++;
         }