invert logic around JSON.parse errors - have node syntax by default, Nashorn only behind flag

Author: wirthi

graal-js/src/com.oracle.truffle.js.parser/src/com/oracle/truffle/js/parser/json/JSONParser.java

@@ -474,9 +474,9 @@ private ParserException numberError(final int start) {
     }
 
     private ParserException expectedError(final int start, final String expected, final String found) {
-        return context.isOptionV8CompatibilityMode()
-                        ? expectedErrorV8(start, found)
-                        : error(parserMessage("expected", expected, found), start);
+        return context.isOptionNashornCompatibilityMode()
+                        ? error(parserMessage("expected", expected, found), start)
+                        : expectedErrorV8(start, found);
     }
 
     private static ParserException expectedErrorV8(final int start, final String found) {

graal-js/src/com.oracle.truffle.js.test/src/com/oracle/truffle/js/test/builtins/CommonJSRequireTest.java

@@ -346,10 +346,7 @@ public void testLoadBrokenJson() {
                 throw new AssertionError("Unexpected exception " + t);
             }
             assertEquals(t.getMessage(),
-                            "SyntaxError: Invalid JSON: <json>:1:1 Expected " +
-                                            ", or } but found n\n" +
-                                            "{not_a_valid:##json}\n" +
-                                            " ^");
+                            "SyntaxError: Unexpected token n in JSON at position 1");
         }
     }
 

graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/builtins/helper/TruffleJSONParser.java

@@ -487,9 +487,9 @@ protected Object error(String message) {
 
     @TruffleBoundary
     public static RuntimeException createSyntaxError(Exception ex, JSContext context) {
-        throw context.isOptionV8CompatibilityMode() ? Errors.createSyntaxError(ex.getMessage().replace("\r\n", "\n"))
-                        : Errors.createSyntaxError("Invalid JSON: " +
-                                        ex.getMessage().replace("\r\n", "\n"));
+        String msg = ex.getMessage().replace("\r\n", "\n");
+        throw context.isOptionNashornCompatibilityMode() ? Errors.createSyntaxError("Invalid JSON: " + msg)
+                        : Errors.createSyntaxError(msg);
     }
 
     // ************************* Helper Functions ****************************************//