michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: 
michael@0: /*
michael@0:  * Any copyright is dedicated to the Public Domain.
michael@0:  * http://creativecommons.org/licenses/publicdomain/
michael@0:  */
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Return true if both of these return true:
michael@0:  * - LENIENT_PRED applied to CODE
michael@0:  * - STRICT_PRED applied to CODE with a use strict directive added to the front
michael@0:  *
michael@0:  * Run STRICT_PRED first, for testing code that affects the global environment
michael@0:  * in loose mode, but fails in strict mode.
michael@0:  */
michael@0: function testLenientAndStrict(code, lenient_pred, strict_pred) {
michael@0:   return (strict_pred("'use strict'; " + code) && 
michael@0:           lenient_pred(code));
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * completesNormally(CODE) returns true if evaluating CODE (as eval
michael@0:  * code) completes normally (rather than throwing an exception).
michael@0:  */
michael@0: function completesNormally(code) {
michael@0:   try {
michael@0:     eval(code);
michael@0:     return true;
michael@0:   } catch (exception) {
michael@0:     return false;
michael@0:   }
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * raisesException(EXCEPTION)(CODE) returns true if evaluating CODE (as eval
michael@0:  * code) throws an exception object whose prototype is
michael@0:  * EXCEPTION.prototype, and returns false if it throws any other error
michael@0:  * or evaluates successfully. For example: raises(TypeError)("0()") ==
michael@0:  * true.
michael@0:  */
michael@0: function raisesException(exception) {
michael@0:   return function (code) {
michael@0:     try {
michael@0:       eval(code);
michael@0:       return false;
michael@0:     } catch (actual) {
michael@0:       return exception.prototype.isPrototypeOf(actual);
michael@0:     }
michael@0:   };
michael@0: };
michael@0: 
michael@0: /*
michael@0:  * parsesSuccessfully(CODE) returns true if CODE parses as function
michael@0:  * code without an error.
michael@0:  */
michael@0: function parsesSuccessfully(code) {
michael@0:   try {
michael@0:     Function(code);
michael@0:     return true;
michael@0:   } catch (exception) {
michael@0:     return false;
michael@0:   }
michael@0: };
michael@0: 
michael@0: /*
michael@0:  * parseRaisesException(EXCEPTION)(CODE) returns true if parsing CODE
michael@0:  * as function code raises EXCEPTION.
michael@0:  */
michael@0: function parseRaisesException(exception) {
michael@0:   return function (code) {
michael@0:     try {
michael@0:       Function(code);
michael@0:       return false;
michael@0:     } catch (actual) {
michael@0:       return exception.prototype.isPrototypeOf(actual);
michael@0:     }
michael@0:   };
michael@0: };
michael@0: 
michael@0: /*
michael@0:  * Return the result of applying uneval to VAL, and replacing all runs
michael@0:  * of whitespace with a single horizontal space (poor man's
michael@0:  * tokenization).
michael@0:  */
michael@0: function clean_uneval(val) {
michael@0:   return uneval(val).replace(/\s+/g, ' ');
michael@0: }