Fixed incorrect parsing of paren-expression (#33)

* fixed vulnerabilities

* Fixed incorrect parsing of paren-expressions (#22)

Author: springcomp

src/Parser.ts

@@ -178,17 +178,10 @@ class TokenParser {
         return { type: 'ExpressionReference', child };
       }
       case Token.TOK_LPAREN: {
+        console.log('nud::TOK_LPAREN');
         const args: ExpressionNode[] = [];
-        while (this.lookahead(0) !== Token.TOK_RPAREN) {
-          let expression: ExpressionNode;
-          if (this.lookahead(0) === Token.TOK_CURRENT) {
-            expression = { type: Token.TOK_CURRENT };
-            this.advance();
-          } else {
-            expression = this.expression(0);
-          }
-          args.push(expression);
-        }
+        let expression = this.expression(0);
+        args.push(expression);
         this.match(Token.TOK_RPAREN);
         return args[0];
       }

test/jmespath-parser.spec.ts

@@ -55,4 +55,14 @@ describe('parsing', () => {
       return null;
     }, 'syntax');
   });
+  it('should parse paren expression', () => {
+    // see #22 - issue with parenthesized expression-type
+    const expected = {
+      type: 'AndExpression',
+      left: { type: 'Current' },
+      right: { type: 'Literal' }
+    };
+    expect(compile('  @ && \'truthy\' ')).toMatchObject(expected);
+    expect(compile('( @ && \'truthy\' )')).toMatchObject(expected);
+  });
 });