Files
openlayers/nicer-api-docs/closure-library/closure/goog/debug/debug.js
2014-05-06 13:02:46 -05:00

502 lines
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JavaScript

// Copyright 2006 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview Logging and debugging utilities.
*
* @see ../demos/debug.html
*/
goog.provide('goog.debug');
goog.require('goog.array');
goog.require('goog.string');
goog.require('goog.structs.Set');
goog.require('goog.userAgent');
/** @define {boolean} Whether logging should be enabled. */
goog.define('goog.debug.LOGGING_ENABLED', goog.DEBUG);
/**
* Catches onerror events fired by windows and similar objects.
* @param {function(Object)} logFunc The function to call with the error
* information.
* @param {boolean=} opt_cancel Whether to stop the error from reaching the
* browser.
* @param {Object=} opt_target Object that fires onerror events.
*/
goog.debug.catchErrors = function(logFunc, opt_cancel, opt_target) {
var target = opt_target || goog.global;
var oldErrorHandler = target.onerror;
var retVal = !!opt_cancel;
// Chrome interprets onerror return value backwards (http://crbug.com/92062)
// until it was fixed in webkit revision r94061 (Webkit 535.3). This
// workaround still needs to be skipped in Safari after the webkit change
// gets pushed out in Safari.
// See https://bugs.webkit.org/show_bug.cgi?id=67119
if (goog.userAgent.WEBKIT &&
!goog.userAgent.isVersionOrHigher('535.3')) {
retVal = !retVal;
}
target.onerror = function(message, url, line) {
if (oldErrorHandler) {
oldErrorHandler(message, url, line);
}
logFunc({
message: message,
fileName: url,
line: line
});
return retVal;
};
};
/**
* Creates a string representing an object and all its properties.
* @param {Object|null|undefined} obj Object to expose.
* @param {boolean=} opt_showFn Show the functions as well as the properties,
* default is false.
* @return {string} The string representation of {@code obj}.
*/
goog.debug.expose = function(obj, opt_showFn) {
if (typeof obj == 'undefined') {
return 'undefined';
}
if (obj == null) {
return 'NULL';
}
var str = [];
for (var x in obj) {
if (!opt_showFn && goog.isFunction(obj[x])) {
continue;
}
var s = x + ' = ';
/** @preserveTry */
try {
s += obj[x];
} catch (e) {
s += '*** ' + e + ' ***';
}
str.push(s);
}
return str.join('\n');
};
/**
* Creates a string representing a given primitive or object, and for an
* object, all its properties and nested objects. WARNING: If an object is
* given, it and all its nested objects will be modified. To detect reference
* cycles, this method identifies objects using goog.getUid() which mutates the
* object.
* @param {*} obj Object to expose.
* @param {boolean=} opt_showFn Also show properties that are functions (by
* default, functions are omitted).
* @return {string} A string representation of {@code obj}.
*/
goog.debug.deepExpose = function(obj, opt_showFn) {
var previous = new goog.structs.Set();
var str = [];
var helper = function(obj, space) {
var nestspace = space + ' ';
var indentMultiline = function(str) {
return str.replace(/\n/g, '\n' + space);
};
/** @preserveTry */
try {
if (!goog.isDef(obj)) {
str.push('undefined');
} else if (goog.isNull(obj)) {
str.push('NULL');
} else if (goog.isString(obj)) {
str.push('"' + indentMultiline(obj) + '"');
} else if (goog.isFunction(obj)) {
str.push(indentMultiline(String(obj)));
} else if (goog.isObject(obj)) {
if (previous.contains(obj)) {
// TODO(user): This is a bug; it falsely detects non-loops as loops
// when the reference tree contains two references to the same object.
str.push('*** reference loop detected ***');
} else {
previous.add(obj);
str.push('{');
for (var x in obj) {
if (!opt_showFn && goog.isFunction(obj[x])) {
continue;
}
str.push('\n');
str.push(nestspace);
str.push(x + ' = ');
helper(obj[x], nestspace);
}
str.push('\n' + space + '}');
}
} else {
str.push(obj);
}
} catch (e) {
str.push('*** ' + e + ' ***');
}
};
helper(obj, '');
return str.join('');
};
/**
* Recursively outputs a nested array as a string.
* @param {Array} arr The array.
* @return {string} String representing nested array.
*/
goog.debug.exposeArray = function(arr) {
var str = [];
for (var i = 0; i < arr.length; i++) {
if (goog.isArray(arr[i])) {
str.push(goog.debug.exposeArray(arr[i]));
} else {
str.push(arr[i]);
}
}
return '[ ' + str.join(', ') + ' ]';
};
/**
* Exposes an exception that has been caught by a try...catch and outputs the
* error with a stack trace.
* @param {Object} err Error object or string.
* @param {Function=} opt_fn Optional function to start stack trace from.
* @return {string} Details of exception.
*/
goog.debug.exposeException = function(err, opt_fn) {
/** @preserveTry */
try {
var e = goog.debug.normalizeErrorObject(err);
// Create the error message
var error = 'Message: ' + goog.string.htmlEscape(e.message) +
'\nUrl: <a href="view-source:' + e.fileName + '" target="_new">' +
e.fileName + '</a>\nLine: ' + e.lineNumber + '\n\nBrowser stack:\n' +
goog.string.htmlEscape(e.stack + '-> ') +
'[end]\n\nJS stack traversal:\n' + goog.string.htmlEscape(
goog.debug.getStacktrace(opt_fn) + '-> ');
return error;
} catch (e2) {
return 'Exception trying to expose exception! You win, we lose. ' + e2;
}
};
/**
* Normalizes the error/exception object between browsers.
* @param {Object} err Raw error object.
* @return {Object} Normalized error object.
*/
goog.debug.normalizeErrorObject = function(err) {
var href = goog.getObjectByName('window.location.href');
if (goog.isString(err)) {
return {
'message': err,
'name': 'Unknown error',
'lineNumber': 'Not available',
'fileName': href,
'stack': 'Not available'
};
}
var lineNumber, fileName;
var threwError = false;
try {
lineNumber = err.lineNumber || err.line || 'Not available';
} catch (e) {
// Firefox 2 sometimes throws an error when accessing 'lineNumber':
// Message: Permission denied to get property UnnamedClass.lineNumber
lineNumber = 'Not available';
threwError = true;
}
try {
fileName = err.fileName || err.filename || err.sourceURL ||
// $googDebugFname may be set before a call to eval to set the filename
// that the eval is supposed to present.
goog.global['$googDebugFname'] || href;
} catch (e) {
// Firefox 2 may also throw an error when accessing 'filename'.
fileName = 'Not available';
threwError = true;
}
// The IE Error object contains only the name and the message.
// The Safari Error object uses the line and sourceURL fields.
if (threwError || !err.lineNumber || !err.fileName || !err.stack ||
!err.message || !err.name) {
return {
'message': err.message || 'Not available',
'name': err.name || 'UnknownError',
'lineNumber': lineNumber,
'fileName': fileName,
'stack': err.stack || 'Not available'
};
}
// Standards error object
return err;
};
/**
* Converts an object to an Error if it's a String,
* adds a stacktrace if there isn't one,
* and optionally adds an extra message.
* @param {Error|string} err the original thrown object or string.
* @param {string=} opt_message optional additional message to add to the
* error.
* @return {Error} If err is a string, it is used to create a new Error,
* which is enhanced and returned. Otherwise err itself is enhanced
* and returned.
*/
goog.debug.enhanceError = function(err, opt_message) {
var error = typeof err == 'string' ? Error(err) : err;
if (!error.stack) {
error.stack = goog.debug.getStacktrace(arguments.callee.caller);
}
if (opt_message) {
// find the first unoccupied 'messageX' property
var x = 0;
while (error['message' + x]) {
++x;
}
error['message' + x] = String(opt_message);
}
return error;
};
/**
* Gets the current stack trace. Simple and iterative - doesn't worry about
* catching circular references or getting the args.
* @param {number=} opt_depth Optional maximum depth to trace back to.
* @return {string} A string with the function names of all functions in the
* stack, separated by \n.
*/
goog.debug.getStacktraceSimple = function(opt_depth) {
var sb = [];
var fn = arguments.callee.caller;
var depth = 0;
while (fn && (!opt_depth || depth < opt_depth)) {
sb.push(goog.debug.getFunctionName(fn));
sb.push('()\n');
/** @preserveTry */
try {
fn = fn.caller;
} catch (e) {
sb.push('[exception trying to get caller]\n');
break;
}
depth++;
if (depth >= goog.debug.MAX_STACK_DEPTH) {
sb.push('[...long stack...]');
break;
}
}
if (opt_depth && depth >= opt_depth) {
sb.push('[...reached max depth limit...]');
} else {
sb.push('[end]');
}
return sb.join('');
};
/**
* Max length of stack to try and output
* @type {number}
*/
goog.debug.MAX_STACK_DEPTH = 50;
/**
* Gets the current stack trace, either starting from the caller or starting
* from a specified function that's currently on the call stack.
* @param {Function=} opt_fn Optional function to start getting the trace from.
* If not provided, defaults to the function that called this.
* @return {string} Stack trace.
*/
goog.debug.getStacktrace = function(opt_fn) {
return goog.debug.getStacktraceHelper_(opt_fn || arguments.callee.caller, []);
};
/**
* Private helper for getStacktrace().
* @param {Function} fn Function to start getting the trace from.
* @param {Array} visited List of functions visited so far.
* @return {string} Stack trace starting from function fn.
* @private
*/
goog.debug.getStacktraceHelper_ = function(fn, visited) {
var sb = [];
// Circular reference, certain functions like bind seem to cause a recursive
// loop so we need to catch circular references
if (goog.array.contains(visited, fn)) {
sb.push('[...circular reference...]');
// Traverse the call stack until function not found or max depth is reached
} else if (fn && visited.length < goog.debug.MAX_STACK_DEPTH) {
sb.push(goog.debug.getFunctionName(fn) + '(');
var args = fn.arguments;
for (var i = 0; i < args.length; i++) {
if (i > 0) {
sb.push(', ');
}
var argDesc;
var arg = args[i];
switch (typeof arg) {
case 'object':
argDesc = arg ? 'object' : 'null';
break;
case 'string':
argDesc = arg;
break;
case 'number':
argDesc = String(arg);
break;
case 'boolean':
argDesc = arg ? 'true' : 'false';
break;
case 'function':
argDesc = goog.debug.getFunctionName(arg);
argDesc = argDesc ? argDesc : '[fn]';
break;
case 'undefined':
default:
argDesc = typeof arg;
break;
}
if (argDesc.length > 40) {
argDesc = argDesc.substr(0, 40) + '...';
}
sb.push(argDesc);
}
visited.push(fn);
sb.push(')\n');
/** @preserveTry */
try {
sb.push(goog.debug.getStacktraceHelper_(fn.caller, visited));
} catch (e) {
sb.push('[exception trying to get caller]\n');
}
} else if (fn) {
sb.push('[...long stack...]');
} else {
sb.push('[end]');
}
return sb.join('');
};
/**
* Set a custom function name resolver.
* @param {function(Function): string} resolver Resolves functions to their
* names.
*/
goog.debug.setFunctionResolver = function(resolver) {
goog.debug.fnNameResolver_ = resolver;
};
/**
* Gets a function name
* @param {Function} fn Function to get name of.
* @return {string} Function's name.
*/
goog.debug.getFunctionName = function(fn) {
if (goog.debug.fnNameCache_[fn]) {
return goog.debug.fnNameCache_[fn];
}
if (goog.debug.fnNameResolver_) {
var name = goog.debug.fnNameResolver_(fn);
if (name) {
goog.debug.fnNameCache_[fn] = name;
return name;
}
}
// Heuristically determine function name based on code.
var functionSource = String(fn);
if (!goog.debug.fnNameCache_[functionSource]) {
var matches = /function ([^\(]+)/.exec(functionSource);
if (matches) {
var method = matches[1];
goog.debug.fnNameCache_[functionSource] = method;
} else {
goog.debug.fnNameCache_[functionSource] = '[Anonymous]';
}
}
return goog.debug.fnNameCache_[functionSource];
};
/**
* Makes whitespace visible by replacing it with printable characters.
* This is useful in finding diffrences between the expected and the actual
* output strings of a testcase.
* @param {string} string whose whitespace needs to be made visible.
* @return {string} string whose whitespace is made visible.
*/
goog.debug.makeWhitespaceVisible = function(string) {
return string.replace(/ /g, '[_]')
.replace(/\f/g, '[f]')
.replace(/\n/g, '[n]\n')
.replace(/\r/g, '[r]')
.replace(/\t/g, '[t]');
};
/**
* Hash map for storing function names that have already been looked up.
* @type {Object}
* @private
*/
goog.debug.fnNameCache_ = {};
/**
* Resolves functions to their names. Resolved function names will be cached.
* @type {function(Function):string}
* @private
*/
goog.debug.fnNameResolver_;