Fixed PEG.buildParser's documentation and added a test.

lib/compiler.js

@@ -15,9 +15,10 @@ function nop() {}
  * metagrammar.pegjs file. The start rule may be unspecified, in which case
  * "start" is used.
  *
- * Throws |PEG.Grammar.GrammarError| if the grammar contains an error. Note that
- * not all errors are detected during the generation and some may protrude to
- * the generated parser and cause its malfunction.
+ * Throws |PEG.grammarParser.SyntaxError| if the grammar contains a syntax error
+ * or |PEG.Grammar.GrammarError| if it contains a semantic error. Note that not
+ * all errors are detected during the generation and some may protrude to the
+ * generated parser and cause its malfunction.
  */
 PEG.buildParser = function(grammar, startRule) {
   startRule = startRule || "start";

test/compiler-test.js

@@ -169,6 +169,13 @@ test("generateUniqueIdentifier", function() {
 
 module("PEG");
 
+test("buildParser reports syntax errors in the grammar", function() {
+  throws(
+    function() { PEG.buildParser(''); },
+    PEG.grammarParser.SyntaxError
+  );
+});
+
 test("buildParser reports missing start rule", function() {
   throws(
     function() { PEG.buildParser('notStart: "abcd"'); },