Improve output: distinguish between failed assertions (failures) and unexpected exceptions (errors), and print a filtered stack trace for any exception.

webapp/web/src/lang/assert.js

@@ -0,0 +1,121 @@
+/*
+	Copyright (c) 2004-2006, The Dojo Foundation
+	All Rights Reserved.
+
+	Licensed under the Academic Free License version 2.1 or above OR the
+	modified BSD license. For more information on Dojo licensing, see:
+
+		http://dojotoolkit.org/community/licensing.shtml
+*/
+
+dojo.provide("dojo.lang.assert");
+
+dojo.require("dojo.lang.common");
+dojo.require("dojo.lang.array");
+dojo.require("dojo.lang.type");
+
+// -------------------------------------------------------------------
+// Assertion methods
+// -------------------------------------------------------------------
+
+/**
+ * Throws an exception if the assertion fails.
+ *
+ * If the asserted condition is true, this method does nothing. If the
+ * condition is false, we throw an error with a error message.  
+ *
+ * @param	booleanValue	A boolean value, which needs to be true for the assertion to succeed.
+ * @param	message	Optional. A string describing the assertion.
+ * @throws	Throws an Error if 'booleanValue' is false.
+ */
+dojo.lang.assert = function(booleanValue, message){
+	if(!booleanValue){
+		var errorMessage = "An assert statement failed.\n" +
+			"The method dojo.lang.assert() was called with a 'false' value.\n";
+		if(message){
+			errorMessage += "Here's the assert message:\n" + message + "\n";
+		}
+		// Use throw instead of dojo.raise, until bug #264 is fixed:
+		// dojo.raise(errorMessage);
+		throw new Error(errorMessage);
+	}
+}
+
+/**
+ * Given a value and a data type, this method checks the type of the value
+ * to make sure it matches the data type, and throws an exception if there
+ * is a mismatch.
+ *
+ * Examples:
+ * <pre>
+ *   dojo.lang.assertType("foo", String);
+ *   dojo.lang.assertType(12345, Number);
+ *   dojo.lang.assertType(false, Boolean);
+ *   dojo.lang.assertType([6, 8], Array);
+ *   dojo.lang.assertType(dojo.lang.assertType, Function);
+ *   dojo.lang.assertType({foo: "bar"}, Object);
+ *   dojo.lang.assertType(new Date(), Date);
+ * </pre>
+ *
+ * @scope	public function
+ * @param	value	Any literal value or object instance.
+ * @param	type	A class of object, or a literal type, or the string name of a type, or an array with a list of types.
+ * @param	message	Optional. A string describing the assertion.
+ * @throws	Throws an Error if 'value' is not of type 'type'.
+ */
+dojo.lang.assertType = function(value, type, message){
+	if(!dojo.lang.isOfType(value, type)){
+		if(!message){
+			if(!dojo.lang.assertType._errorMessage){
+				dojo.lang.assertType._errorMessage = "Type mismatch: dojo.lang.assertType() failed.";
+			}
+			message = dojo.lang.assertType._errorMessage;
+		}
+		dojo.lang.assert(false, message);
+	}
+}
+
+/**
+ * Given an anonymous object and a list of expected property names, this
+ * method check to make sure the object does not have any properties
+ * that aren't on the list of expected properties, and throws an Error
+ * if there are unexpected properties. This is useful for doing error
+ * checking on keyword arguments, to make sure there aren't typos.
+ *
+ * Examples:
+ * <pre>
+ *   dojo.lang.assertValidKeywords({a: 1, b: 2}, ["a", "b"]);
+ *   dojo.lang.assertValidKeywords({a: 1, b: 2}, ["a", "b", "c"]);
+ *   dojo.lang.assertValidKeywords({foo: "iggy"}, ["foo"]);
+ *   dojo.lang.assertValidKeywords({foo: "iggy"}, ["foo", "bar"]);
+ *   dojo.lang.assertValidKeywords({foo: "iggy"}, {foo: null, bar: null});
+ * </pre>
+ *
+ * @scope	public function
+ * @param	object	An anonymous object.
+ * @param	expectedProperties	An array of strings (or an object with all the expected properties).
+ * @param	message	Optional. A string describing the assertion.
+ * @throws	Throws an Error if 'value' is not of type 'type'.
+ */
+dojo.lang.assertValidKeywords = function(object, expectedProperties, message){
+	var key;
+	if(!message){
+		if(!dojo.lang.assertValidKeywords._errorMessage){
+			dojo.lang.assertValidKeywords._errorMessage = "In dojo.lang.assertValidKeywords(), found invalid keyword:";
+		}
+		message = dojo.lang.assertValidKeywords._errorMessage;
+	}
+	if(dojo.lang.isArray(expectedProperties)){
+		for(key in object){
+			if(!dojo.lang.inArray(expectedProperties, key)){
+				dojo.lang.assert(false, message + " " + key);
+			}
+		}
+	}else{
+		for(key in object){
+			if(!(key in expectedProperties)){
+				dojo.lang.assert(false, message + " " + key);
+			}
+		}
+	}
+}