Merge branch 'MDL-29201_20' of git://github.com/timhunt/moodle into MOODLE_20_STABLE

[moodle.git] / lib / simpletestlib / web_tester.php

<?php
/**
 *  Base include file for SimpleTest.
 *  @package    SimpleTest
 *  @subpackage WebTester
 *  @version    $Id$
 */

/**#@+
 *  include other SimpleTest class files
 */
require_once(dirname(__FILE__) . '/test_case.php');
require_once(dirname(__FILE__) . '/browser.php');
require_once(dirname(__FILE__) . '/page.php');
require_once(dirname(__FILE__) . '/expectation.php');
/**#@-*/

/**
 *    Test for an HTML widget value match.
 *    @package SimpleTest
 *    @subpackage WebTester
 */
class FieldExpectation extends SimpleExpectation {
    var $_value;
    
    /**
     *    Sets the field value to compare against.
     *    @param mixed $value     Test value to match. Can be an
     *                            expectation for say pattern matching.
     *    @param string $message  Optiona message override. Can use %s as
     *                            a placeholder for the original message.
     *    @access public
     */
    function FieldExpectation($value, $message = '%s') {
        $this->SimpleExpectation($message);
        if (is_array($value)) {
            sort($value);
        }
        $this->_value = $value;
    }
    
    /**
     *    Tests the expectation. True if it matches
     *    a string value or an array value in any order.
     *    @param mixed $compare        Comparison value. False for
     *                                 an unset field.
     *    @return boolean              True if correct.
     *    @access public
     */
    function test($compare) {
        if ($this->_value === false) {
            return ($compare === false);
        }
        if ($this->_isSingle($this->_value)) {
            return $this->_testSingle($compare);
        }
        if (is_array($this->_value)) {
            return $this->_testMultiple($compare);
        }
        return false;
    }
    
    /**
     *    Tests for valid field comparisons with a single option.
     *    @param mixed $value       Value to type check.
     *    @return boolean           True if integer, string or float.
     *    @access private
     */
    function _isSingle($value) {
        return is_string($value) || is_integer($value) || is_float($value);
    }
    
    /**
     *    String comparison for simple field with a single option.
     *    @param mixed $compare    String to test against.
     *    @returns boolean         True if matching.
     *    @access private
     */
    function _testSingle($compare) {
        if (is_array($compare) && count($compare) == 1) {
            $compare = $compare[0];
        }
        if (! $this->_isSingle($compare)) {
            return false;
        }
        return ($this->_value == $compare);
    }
    
    /**
     *    List comparison for multivalue field.
     *    @param mixed $compare    List in any order to test against.
     *    @returns boolean         True if matching.
     *    @access private
     */
    function _testMultiple($compare) {
        if (is_string($compare)) {
            $compare = array($compare);
        }
        if (! is_array($compare)) {
            return false;
        }
        sort($compare);
        return ($this->_value === $compare);
    }
    
    /**
     *    Returns a human readable test message.
     *    @param mixed $compare      Comparison value.
     *    @return string             Description of success
     *                               or failure.
     *    @access public
     */
    function testMessage($compare) {
        $dumper = &$this->_getDumper();
        if (is_array($compare)) {
            sort($compare);
        }
        if ($this->test($compare)) {
            return "Field expectation [" . $dumper->describeValue($this->_value) . "]";
        } else {
            return "Field expectation [" . $dumper->describeValue($this->_value) .
                    "] fails with [" .
                    $dumper->describeValue($compare) . "] " .
                    $dumper->describeDifference($this->_value, $compare);
        }
    }
}

/**
 *    Test for a specific HTTP header within a header block.
 *    @package SimpleTest
 *    @subpackage WebTester
 */
class HttpHeaderExpectation extends SimpleExpectation {
    var $_expected_header;
    var $_expected_value;
    
    /**
     *    Sets the field and value to compare against.
     *    @param string $header   Case insenstive trimmed header name.
     *    @param mixed $value     Optional value to compare. If not
     *                            given then any value will match. If
     *                            an expectation object then that will
     *                            be used instead.
     *    @param string $message  Optiona message override. Can use %s as
     *                            a placeholder for the original message.
     */
    function HttpHeaderExpectation($header, $value = false, $message = '%s') {
        $this->SimpleExpectation($message);
        $this->_expected_header = $this->_normaliseHeader($header);
        $this->_expected_value = $value;
    }
    
    /**
     *    Accessor for aggregated object.
     *    @return mixed        Expectation set in constructor.
     *    @access protected
     */
    function _getExpectation() {
        return $this->_expected_value;
    }
    
    /**
     *    Removes whitespace at ends and case variations.
     *    @param string $header    Name of header.
     *    @param string            Trimmed and lowecased header
     *                             name.
     *    @access private
     */
    function _normaliseHeader($header) {
        return strtolower(trim($header));
    }
    
    /**
     *    Tests the expectation. True if it matches
     *    a string value or an array value in any order.
     *    @param mixed $compare   Raw header block to search.
     *    @return boolean         True if header present.
     *    @access public
     */
    function test($compare) {
        return is_string($this->_findHeader($compare));
    }
    
    /**
     *    Searches the incoming result. Will extract the matching
     *    line as text.
     *    @param mixed $compare   Raw header block to search.
     *    @return string          Matching header line.
     *    @access protected
     */
    function _findHeader($compare) {
        $lines = explode("\r\n", $compare);
        foreach ($lines as $line) {
            if ($this->_testHeaderLine($line)) {
                return $line;
            }
        }
        return false;
    }
    
    /**
     *    Compares a single header line against the expectation.
     *    @param string $line      A single line to compare.
     *    @return boolean          True if matched.
     *    @access private
     */
    function _testHeaderLine($line) {
        if (count($parsed = explode(':', $line, 2)) < 2) {
            return false;
        }
        list($header, $value) = $parsed;
        if ($this->_normaliseHeader($header) != $this->_expected_header) {
            return false;
        }
        return $this->_testHeaderValue($value, $this->_expected_value);
    }
    
    /**
     *    Tests the value part of the header.
     *    @param string $value        Value to test.
     *    @param mixed $expected      Value to test against.
     *    @return boolean             True if matched.
     *    @access protected
     */
    function _testHeaderValue($value, $expected) {
        if ($expected === false) {
            return true;
        }
        if (SimpleExpectation::isExpectation($expected)) {
            return $expected->test(trim($value));
        }
        return (trim($value) == trim($expected));
    }
    
    /**
     *    Returns a human readable test message.
     *    @param mixed $compare      Raw header block to search.
     *    @return string             Description of success
     *                               or failure.
     *    @access public
     */
    function testMessage($compare) {
        if (SimpleExpectation::isExpectation($this->_expected_value)) {
            $message = $this->_expected_value->overlayMessage($compare, $this->_getDumper());
        } else {
            $message = $this->_expected_header .
                    ($this->_expected_value ? ': ' . $this->_expected_value : '');
        }
        if (is_string($line = $this->_findHeader($compare))) {
            return "Searching for header [$message] found [$line]";
        } else {
            return "Failed to find header [$message]";
        }
    }
}
    
/**
 *    Test for a specific HTTP header within a header block that
 *    should not be found.
 *    @package SimpleTest
 *    @subpackage WebTester
 */
class NoHttpHeaderExpectation extends HttpHeaderExpectation {
    var $_expected_header;
    var $_expected_value;
    
    /**
     *    Sets the field and value to compare against.
     *    @param string $unwanted   Case insenstive trimmed header name.
     *    @param string $message    Optiona message override. Can use %s as
     *                              a placeholder for the original message.
     */
    function NoHttpHeaderExpectation($unwanted, $message = '%s') {
        $this->HttpHeaderExpectation($unwanted, false, $message);
    }
    
    /**
     *    Tests that the unwanted header is not found.
     *    @param mixed $compare   Raw header block to search.
     *    @return boolean         True if header present.
     *    @access public
     */
    function test($compare) {
        return ($this->_findHeader($compare) === false);
    }
    
    /**
     *    Returns a human readable test message.
     *    @param mixed $compare      Raw header block to search.
     *    @return string             Description of success
     *                               or failure.
     *    @access public
     */
    function testMessage($compare) {
        $expectation = $this->_getExpectation();
        if (is_string($line = $this->_findHeader($compare))) {
            return "Found unwanted header [$expectation] with [$line]";
        } else {
            return "Did not find unwanted header [$expectation]";
        }
    }
}

/**
 *    Test for a text substring.
 *    @package SimpleTest
 *    @subpackage UnitTester
 */
class TextExpectation extends SimpleExpectation {
    var $_substring;
    
    /**
     *    Sets the value to compare against.
     *    @param string $substring  Text to search for.
     *    @param string $message    Customised message on failure.
     *    @access public
     */
    function TextExpectation($substring, $message = '%s') {
        $this->SimpleExpectation($message);
        $this->_substring = $substring;
    }
    
    /**
     *    Accessor for the substring.
     *    @return string       Text to match.
     *    @access protected
     */
    function _getSubstring() {
        return $this->_substring;
    }
    
    /**
     *    Tests the expectation. True if the text contains the
     *    substring.
     *    @param string $compare        Comparison value.
     *    @return boolean               True if correct.
     *    @access public
     */
    function test($compare) {
        return (strpos($compare, $this->_substring) !== false);
    }
    
    /**
     *    Returns a human readable test message.
     *    @param mixed $compare      Comparison value.
     *    @return string             Description of success
     *                               or failure.
     *    @access public
     */
    function testMessage($compare) {
        if ($this->test($compare)) {
            return $this->_describeTextMatch($this->_getSubstring(), $compare);
        } else {
            $dumper = &$this->_getDumper();
            return "Text [" . $this->_getSubstring() .
                    "] not detected in [" .
                    $dumper->describeValue($compare) . "]";
        }
    }
    
    /**
     *    Describes a pattern match including the string
     *    found and it's position.
     *    @param string $substring      Text to search for.
     *    @param string $subject        Subject to search.
     *    @access protected
     */
    function _describeTextMatch($substring, $subject) {
        $position = strpos($subject, $substring);
        $dumper = &$this->_getDumper();
        return "Text [$substring] detected at character [$position] in [" .
                $dumper->describeValue($subject) . "] in region [" .
                $dumper->clipString($subject, 100, $position) . "]";
    }
}

/**
 *    Fail if a substring is detected within the
 *    comparison text.
 *    @package SimpleTest
 *    @subpackage UnitTester
 */
class NoTextExpectation extends TextExpectation {
    
    /**
     *    Sets the reject pattern
     *    @param string $substring  Text to search for.
     *    @param string $message    Customised message on failure.
     *    @access public
     */
    function NoTextExpectation($substring, $message = '%s') {
        $this->TextExpectation($substring, $message);
    }
    
    /**
     *    Tests the expectation. False if the substring appears
     *    in the text.
     *    @param string $compare        Comparison value.
     *    @return boolean               True if correct.
     *    @access public
     */
    function test($compare) {
        return ! parent::test($compare);
    }
    
    /**
     *    Returns a human readable test message.
     *    @param string $compare      Comparison value.
     *    @return string              Description of success
     *                                or failure.
     *    @access public
     */
    function testMessage($compare) {
        if ($this->test($compare)) {
            $dumper = &$this->_getDumper();
            return "Text [" . $this->_getSubstring() .
                    "] not detected in [" .
                    $dumper->describeValue($compare) . "]";
        } else {
            return $this->_describeTextMatch($this->_getSubstring(), $compare);
        }
    }
}

/**
 *    Test case for testing of web pages. Allows
 *    fetching of pages, parsing of HTML and
 *    submitting forms.
 *    @package SimpleTest
 *    @subpackage WebTester
 */
class WebTestCase extends SimpleTestCase {
    var $_browser;
    var $_ignore_errors = false;
    
    /**
     *    Creates an empty test case. Should be subclassed
     *    with test methods for a functional test case.
     *    @param string $label     Name of test case. Will use
     *                             the class name if none specified.
     *    @access public
     */
    function WebTestCase($label = false) {
        $this->SimpleTestCase($label);
    }
    
    /**
     *    Announces the start of the test.
     *    @param string $method    Test method just started.
     *    @access public
     */
    function before($method) {
        parent::before($method);
        $this->setBrowser($this->createBrowser());
    }

    /**
     *    Announces the end of the test. Includes private clean up.
     *    @param string $method    Test method just finished.
     *    @access public
     */
    function after($method) {
        $this->unsetBrowser();
        parent::after($method);
    }
    
    /**
     *    Gets a current browser reference for setting
     *    special expectations or for detailed
     *    examination of page fetches.
     *    @return SimpleBrowser     Current test browser object.
     *    @access public
     */
    function &getBrowser() {
        return $this->_browser;
    }
    
    /**
     *    Gets a current browser reference for setting
     *    special expectations or for detailed
     *    examination of page fetches.
     *    @param SimpleBrowser $browser    New test browser object.
     *    @access public
     */
    function setBrowser(&$browser) {
        return $this->_browser = &$browser;
    }
        
    /**
     *    Clears the current browser reference to help the
     *    PHP garbage collector.
     *    @access public
     */
    function unsetBrowser() {
        unset($this->_browser);
    }
    
    /**
     *    Creates a new default web browser object.
     *    Will be cleared at the end of the test method.
     *    @return TestBrowser           New browser.
     *    @access public
     */
    function &createBrowser() {
        $browser = new SimpleBrowser();
        return $browser;
    }
    
    /**
     *    Gets the last response error.
     *    @return string    Last low level HTTP error.
     *    @access public
     */
    function getTransportError() {
        return $this->_browser->getTransportError();
    }
        
    /**
     *    Accessor for the currently selected URL.
     *    @return string        Current location or false if
     *                          no page yet fetched.
     *    @access public
     */
    function getUrl() {
        return $this->_browser->getUrl();
    }
    
    /**
     *    Dumps the current request for debugging.
     *    @access public
     */
    function showRequest() {
        $this->dump($this->_browser->getRequest());
    }
    
    /**
     *    Dumps the current HTTP headers for debugging.
     *    @access public
     */
    function showHeaders() {
        $this->dump($this->_browser->getHeaders());
    }
    
    /**
     *    Dumps the current HTML source for debugging.
     *    @access public
     */
    function showSource() {
        $this->dump($this->_browser->getContent());
    }
    
    /**
     *    Dumps the visible text only for debugging.
     *    @access public
     */
    function showText() {
        $this->dump(wordwrap($this->_browser->getContentAsText(), 80));
    }
    
    /**
     *    Simulates the closing and reopening of the browser.
     *    Temporary cookies will be discarded and timed
     *    cookies will be expired if later than the
     *    specified time.
     *    @param string/integer $date Time when session restarted.
     *                                If ommitted then all persistent
     *                                cookies are kept. Time is either
     *                                Cookie format string or timestamp.
     *    @access public
     */
    function restart($date = false) {
        if ($date === false) {
            $date = time();
        }
        $this->_browser->restart($date);
    }
    
    /**
     *    Moves cookie expiry times back into the past.
     *    Useful for testing timeouts and expiries.
     *    @param integer $interval    Amount to age in seconds.
     *    @access public
     */
    function ageCookies($interval) {
        $this->_browser->ageCookies($interval);
    }
    
    /**
     *    Disables frames support. Frames will not be fetched
     *    and the frameset page will be used instead.
     *    @access public
     */
    function ignoreFrames() {
        $this->_browser->ignoreFrames();
    }
    
    /**
     *    Switches off cookie sending and recieving.
     *    @access public
     */
    function ignoreCookies() {
        $this->_browser->ignoreCookies();
    }
    
    /**
     *    Skips errors for the next request only. You might
     *    want to confirm that a page is unreachable for
     *    example.
     *    @access public
     */
    function ignoreErrors() {
        $this->_ignore_errors = true;
    }
    
    /**
     *    Issues a fail if there is a transport error anywhere
     *    in the current frameset. Only one such error is
     *    reported.
     *    @param string/boolean $result   HTML or failure.
     *    @return string/boolean $result  Passes through result.
     *    @access private
     */
    function _failOnError($result) {
        if (! $this->_ignore_errors) {
            if ($error = $this->_browser->getTransportError()) {
                $this->fail($error);
            }
        }
        $this->_ignore_errors = false;
        return $result;
    }

    /**
     *    Adds a header to every fetch.
     *    @param string $header       Header line to add to every
     *                                request until cleared.
     *    @access public
     */
    function addHeader($header) {
        $this->_browser->addHeader($header);
    }
    
    /**
     *    Sets the maximum number of redirects before
     *    the web page is loaded regardless.
     *    @param integer $max        Maximum hops.
     *    @access public
     */
    function setMaximumRedirects($max) {
        if (! $this->_browser) {
            trigger_error(
                    'Can only set maximum redirects in a test method, setUp() or tearDown()');
        }
        $this->_browser->setMaximumRedirects($max);
    }
    
    /**
     *    Sets the socket timeout for opening a connection and
     *    receiving at least one byte of information.
     *    @param integer $timeout      Maximum time in seconds.
     *    @access public
     */
    function setConnectionTimeout($timeout) {
        $this->_browser->setConnectionTimeout($timeout);
    }
    
    /**
     *    Sets proxy to use on all requests for when
     *    testing from behind a firewall. Set URL
     *    to false to disable.
     *    @param string $proxy        Proxy URL.
     *    @param string $username     Proxy username for authentication.
     *    @param string $password     Proxy password for authentication.
     *    @access public
     */
    function useProxy($proxy, $username = false, $password = false) {
        $this->_browser->useProxy($proxy, $username, $password);
    }
    
    /**
     *    Fetches a page into the page buffer. If
     *    there is no base for the URL then the
     *    current base URL is used. After the fetch
     *    the base URL reflects the new location.
     *    @param string $url          URL to fetch.
     *    @param hash $parameters     Optional additional GET data.
     *    @return boolean/string      Raw page on success.
     *    @access public
     */
    function get($url, $parameters = false) {
        return $this->_failOnError($this->_browser->get($url, $parameters));
    }
    
    /**
     *    Fetches a page by POST into the page buffer.
     *    If there is no base for the URL then the
     *    current base URL is used. After the fetch
     *    the base URL reflects the new location.
     *    @param string $url          URL to fetch.
     *    @param hash $parameters     Optional additional GET data.
     *    @return boolean/string      Raw page on success.
     *    @access public
     */
    function post($url, $parameters = false) {
        return $this->_failOnError($this->_browser->post($url, $parameters));
    }
    
    /**
     *    Does a HTTP HEAD fetch, fetching only the page
     *    headers. The current base URL is unchanged by this.
     *    @param string $url          URL to fetch.
     *    @param hash $parameters     Optional additional GET data.
     *    @return boolean             True on success.
     *    @access public
     */
    function head($url, $parameters = false) {
        return $this->_failOnError($this->_browser->head($url, $parameters));
    }
    
    /**
     *    Equivalent to hitting the retry button on the
     *    browser. Will attempt to repeat the page fetch.
     *    @return boolean     True if fetch succeeded.
     *    @access public
     */
    function retry() {
        return $this->_failOnError($this->_browser->retry());
    }
    
    /**
     *    Equivalent to hitting the back button on the
     *    browser.
     *    @return boolean     True if history entry and
     *                        fetch succeeded.
     *    @access public
     */
    function back() {
        return $this->_failOnError($this->_browser->back());
    }
    
    /**
     *    Equivalent to hitting the forward button on the
     *    browser.
     *    @return boolean     True if history entry and
     *                        fetch succeeded.
     *    @access public
     */
    function forward() {
        return $this->_failOnError($this->_browser->forward());
    }
    
    /**
     *    Retries a request after setting the authentication
     *    for the current realm.
     *    @param string $username    Username for realm.
     *    @param string $password    Password for realm.
     *    @return boolean/string     HTML on successful fetch. Note
     *                               that authentication may still have
     *                               failed.
     *    @access public
     */
    function authenticate($username, $password) {
        return $this->_failOnError(
                $this->_browser->authenticate($username, $password));
    }
    
    /**
     *    Gets the cookie value for the current browser context.
     *    @param string $name          Name of cookie.
     *    @return string               Value of cookie or false if unset.
     *    @access public
     */
    function getCookie($name) {
        return $this->_browser->getCurrentCookieValue($name);
    }
    
    /**
     *    Sets a cookie in the current browser.
     *    @param string $name          Name of cookie.
     *    @param string $value         Cookie value.
     *    @param string $host          Host upon which the cookie is valid.
     *    @param string $path          Cookie path if not host wide.
     *    @param string $expiry        Expiry date.
     *    @access public
     */
    function setCookie($name, $value, $host = false, $path = '/', $expiry = false) {
        $this->_browser->setCookie($name, $value, $host, $path, $expiry);
    }
    
    /**
     *    Accessor for current frame focus. Will be
     *    false if no frame has focus.
     *    @return integer/string/boolean    Label if any, otherwise
     *                                      the position in the frameset
     *                                      or false if none.
     *    @access public
     */
    function getFrameFocus() {
        return $this->_browser->getFrameFocus();
    }
    
    /**
     *    Sets the focus by index. The integer index starts from 1.
     *    @param integer $choice    Chosen frame.
     *    @return boolean           True if frame exists.
     *    @access public
     */
    function setFrameFocusByIndex($choice) {
        return $this->_browser->setFrameFocusByIndex($choice);
    }
    
    /**
     *    Sets the focus by name.
     *    @param string $name    Chosen frame.
     *    @return boolean        True if frame exists.
     *    @access public
     */
    function setFrameFocus($name) {
        return $this->_browser->setFrameFocus($name);
    }
    
    /**
     *    Clears the frame focus. All frames will be searched
     *    for content.
     *    @access public
     */
    function clearFrameFocus() {
        return $this->_browser->clearFrameFocus();
    }
    
    /**
     *    Clicks a visible text item. Will first try buttons,
     *    then links and then images.
     *    @param string $label        Visible text or alt text.
     *    @return string/boolean      Raw page or false.
     *    @access public
     */
    function click($label) {
        return $this->_failOnError($this->_browser->click($label));
    }
    
    /**
     *    Checks for a click target.
     *    @param string $label        Visible text or alt text.
     *    @return boolean             True if click target.
     *    @access public
     */    
    function assertClickable($label, $message = '%s') {
        return $this->assertTrue(
                $this->_browser->isClickable($label),
                sprintf($message, "Click target [$label] should exist"));
    }
    
    /**
     *    Clicks the submit button by label. The owning
     *    form will be submitted by this.
     *    @param string $label    Button label. An unlabeled
     *                            button can be triggered by 'Submit'.
     *    @param hash $additional Additional form values.
     *    @return boolean/string  Page on success, else false.
     *    @access public
     */
    function clickSubmit($label = 'Submit', $additional = false) {
        return $this->_failOnError(
                $this->_browser->clickSubmit($label, $additional));
    }
    
    /**
     *    Clicks the submit button by name attribute. The owning
     *    form will be submitted by this.
     *    @param string $name     Name attribute of button.
     *    @param hash $additional Additional form values.
     *    @return boolean/string  Page on success.
     *    @access public
     */
    function clickSubmitByName($name, $additional = false) {
        return $this->_failOnError(
                $this->_browser->clickSubmitByName($name, $additional));
    }
    
    /**
     *    Clicks the submit button by ID attribute. The owning
     *    form will be submitted by this.
     *    @param string $id       ID attribute of button.
     *    @param hash $additional Additional form values.
     *    @return boolean/string  Page on success.
     *    @access public
     */
    function clickSubmitById($id, $additional = false) {
        return $this->_failOnError(
                $this->_browser->clickSubmitById($id, $additional));
    }
    
    /**
     *    Checks for a valid button label.
     *    @param string $label        Visible text.
     *    @return boolean             True if click target.
     *    @access public
     */    
    function assertSubmit($label, $message = '%s') {
        return $this->assertTrue(
                $this->_browser->isSubmit($label),
                sprintf($message, "Submit button [$label] should exist"));
    }
    
    /**
     *    Clicks the submit image by some kind of label. Usually
     *    the alt tag or the nearest equivalent. The owning
     *    form will be submitted by this. Clicking outside of
     *    the boundary of the coordinates will result in
     *    a failure.
     *    @param string $label    Alt attribute of button.
     *    @param integer $x       X-coordinate of imaginary click.
     *    @param integer $y       Y-coordinate of imaginary click.
     *    @param hash $additional Additional form values.
     *    @return boolean/string  Page on success.
     *    @access public
     */
    function clickImage($label, $x = 1, $y = 1, $additional = false) {
        return $this->_failOnError(
                $this->_browser->clickImage($label, $x, $y, $additional));
    }
    
    /**
     *    Clicks the submit image by the name. Usually
     *    the alt tag or the nearest equivalent. The owning
     *    form will be submitted by this. Clicking outside of
     *    the boundary of the coordinates will result in
     *    a failure.
     *    @param string $name     Name attribute of button.
     *    @param integer $x       X-coordinate of imaginary click.
     *    @param integer $y       Y-coordinate of imaginary click.
     *    @param hash $additional Additional form values.
     *    @return boolean/string  Page on success.
     *    @access public
     */
    function clickImageByName($name, $x = 1, $y = 1, $additional = false) {
        return $this->_failOnError(
                $this->_browser->clickImageByName($name, $x, $y, $additional));
    }
    
    /**
     *    Clicks the submit image by ID attribute. The owning
     *    form will be submitted by this. Clicking outside of
     *    the boundary of the coordinates will result in
     *    a failure.
     *    @param integer/string $id   ID attribute of button.
     *    @param integer $x           X-coordinate of imaginary click.
     *    @param integer $y           Y-coordinate of imaginary click.
     *    @param hash $additional     Additional form values.
     *    @return boolean/string      Page on success.
     *    @access public
     */
    function clickImageById($id, $x = 1, $y = 1, $additional = false) {
        return $this->_failOnError(
                $this->_browser->clickImageById($id, $x, $y, $additional));
    }
    
    /**
     *    Checks for a valid image with atht alt text or title.
     *    @param string $label        Visible text.
     *    @return boolean             True if click target.
     *    @access public
     */    
    function assertImage($label, $message = '%s') {
        return $this->assertTrue(
                $this->_browser->isImage($label),
                sprintf($message, "Image with text [$label] should exist"));
    }
    
    /**
     *    Submits a form by the ID.
     *    @param string $id       Form ID. No button information
     *                            is submitted this way.
     *    @return boolean/string  Page on success.
     *    @access public
     */
    function submitFormById($id) {
        return $this->_failOnError($this->_browser->submitFormById($id));
    }
    
    /**
     *    Follows a link by name. Will click the first link
     *    found with this link text by default, or a later
     *    one if an index is given. Match is case insensitive
     *    with normalised space.
     *    @param string $label     Text between the anchor tags.
     *    @param integer $index    Link position counting from zero.
     *    @return boolean/string   Page on success.
     *    @access public
     */
    function clickLink($label, $index = 0) {
        return $this->_failOnError($this->_browser->clickLink($label, $index));
    }
    
    /**
     *    Follows a link by id attribute.
     *    @param string $id        ID attribute value.
     *    @return boolean/string   Page on success.
     *    @access public
     */
    function clickLinkById($id) {
        return $this->_failOnError($this->_browser->clickLinkById($id));
    }
    
    /**
     *    Tests for the presence of a link label. Match is
     *    case insensitive with normalised space.
     *    @param string $label     Text between the anchor tags.
     *    @param mixed $expected   Expected URL or expectation object.
     *    @param string $message   Message to display. Default
     *                             can be embedded with %s.
     *    @return boolean          True if link present.
     *    @access public
     */
    function assertLink($label, $expected = true, $message = '%s') {
        $url = $this->_browser->getLink($label);
        if ($expected === true || ($expected !== true && $url === false)) {
            return $this->assertTrue($url !== false, sprintf($message, "Link [$label] should exist"));
        }
        if (! SimpleExpectation::isExpectation($expected)) {
            $expected = new IdenticalExpectation($expected);
        }
        return $this->assert($expected, $url->asString(), sprintf($message, "Link [$label] should match"));
    }

    /**
     *    Tests for the non-presence of a link label. Match is
     *    case insensitive with normalised space.
     *    @param string/integer $label    Text between the anchor tags
     *                                    or ID attribute.
     *    @param string $message          Message to display. Default
     *                                    can be embedded with %s.
     *    @return boolean                 True if link missing.
     *    @access public
     */
    function assertNoLink($label, $message = '%s') {
        return $this->assertTrue(
                $this->_browser->getLink($label) === false,
                sprintf($message, "Link [$label] should not exist"));
    }
    
    /**
     *    Tests for the presence of a link id attribute.
     *    @param string $id        Id attribute value.
     *    @param mixed $expected   Expected URL or expectation object.
     *    @param string $message   Message to display. Default
     *                             can be embedded with %s.
     *    @return boolean          True if link present.
     *    @access public
     */
    function assertLinkById($id, $expected = true, $message = '%s') {
        $url = $this->_browser->getLinkById($id);
        if ($expected === true) {
            return $this->assertTrue($url !== false, sprintf($message, "Link ID [$id] should exist"));
        }
        if (! SimpleExpectation::isExpectation($expected)) {
            $expected = new IdenticalExpectation($expected);
        }
        return $this->assert($expected, $url->asString(), sprintf($message, "Link ID [$id] should match"));
    }

    /**
     *    Tests for the non-presence of a link label. Match is
     *    case insensitive with normalised space.
     *    @param string $id        Id attribute value.
     *    @param string $message   Message to display. Default
     *                             can be embedded with %s.
     *    @return boolean          True if link missing.
     *    @access public
     */
    function assertNoLinkById($id, $message = '%s') {
        return $this->assertTrue(
                $this->_browser->getLinkById($id) === false,
                sprintf($message, "Link ID [$id] should not exist"));
    }
    
    /**
     *    Sets all form fields with that label, or name if there
     *    is no label attached.
     *    @param string $name    Name of field in forms.
     *    @param string $value   New value of field.
     *    @return boolean        True if field exists, otherwise false.
     *    @access public
     */
    function setField($label, $value, $position=false) {
        return $this->_browser->setField($label, $value, $position);
    }
    
    /**
     *    Sets all form fields with that name.
     *    @param string $name    Name of field in forms.
     *    @param string $value   New value of field.
     *    @return boolean        True if field exists, otherwise false.
     *    @access public
     */
    function setFieldByName($name, $value, $position=false) {
        return $this->_browser->setFieldByName($name, $value, $position);
    }
        
    /**
     *    Sets all form fields with that id.
     *    @param string/integer $id   Id of field in forms.
     *    @param string $value        New value of field.
     *    @return boolean             True if field exists, otherwise false.
     *    @access public
     */
    function setFieldById($id, $value) {
        return $this->_browser->setFieldById($id, $value);
    }
    
    /**
     *    Confirms that the form element is currently set
     *    to the expected value. A missing form will always
     *    fail. If no value is given then only the existence
     *    of the field is checked.
     *    @param string $name       Name of field in forms.
     *    @param mixed $expected    Expected string/array value or
     *                              false for unset fields.
     *    @param string $message    Message to display. Default
     *                              can be embedded with %s.
     *    @return boolean           True if pass.
     *    @access public
     */
    function assertField($label, $expected = true, $message = '%s') {
        $value = $this->_browser->getField($label);
        return $this->_assertFieldValue($label, $value, $expected, $message);
    }
    
    /**
     *    Confirms that the form element is currently set
     *    to the expected value. A missing form element will always
     *    fail. If no value is given then only the existence
     *    of the field is checked.
     *    @param string $name       Name of field in forms.
     *    @param mixed $expected    Expected string/array value or
     *                              false for unset fields.
     *    @param string $message    Message to display. Default
     *                              can be embedded with %s.
     *    @return boolean           True if pass.
     *    @access public
     */
    function assertFieldByName($name, $expected = true, $message = '%s') {
        $value = $this->_browser->getFieldByName($name);
        return $this->_assertFieldValue($name, $value, $expected, $message);
    }
        
    /**
     *    Confirms that the form element is currently set
     *    to the expected value. A missing form will always
     *    fail. If no ID is given then only the existence
     *    of the field is checked.
     *    @param string/integer $id  Name of field in forms.
     *    @param mixed $expected     Expected string/array value or
     *                               false for unset fields.
     *    @param string $message     Message to display. Default
     *                               can be embedded with %s.
     *    @return boolean            True if pass.
     *    @access public
     */
    function assertFieldById($id, $expected = true, $message = '%s') {
        $value = $this->_browser->getFieldById($id);
        return $this->_assertFieldValue($id, $value, $expected, $message);
    }
    
    /**
     *    Tests the field value against the expectation.
     *    @param string $identifier      Name, ID or label.
     *    @param mixed $value            Current field value.
     *    @param mixed $expected         Expected value to match.
     *    @param string $message         Failure message.
     *    @return boolean                True if pass
     *    @access protected
     */
    function _assertFieldValue($identifier, $value, $expected, $message) {
        if ($expected === true) {
            return $this->assertTrue(
                    isset($value),
                    sprintf($message, "Field [$identifier] should exist"));
        }
        if (! SimpleExpectation::isExpectation($expected)) {
            $identifier = str_replace('%', '%%', $identifier);
            $expected = new FieldExpectation(
                    $expected,
                    "Field [$identifier] should match with [%s]");
        }
        return $this->assert($expected, $value, $message);
    }
    
    /**
     *    Checks the response code against a list
     *    of possible values.
     *    @param array $responses    Possible responses for a pass.
     *    @param string $message     Message to display. Default
     *                               can be embedded with %s.
     *    @return boolean            True if pass.
     *    @access public
     */
    function assertResponse($responses, $message = '%s') {
        $responses = (is_array($responses) ? $responses : array($responses));
        $code = $this->_browser->getResponseCode();
        $message = sprintf($message, "Expecting response in [" .
                implode(", ", $responses) . "] got [$code]");
        return $this->assertTrue(in_array($code, $responses), $message);
    }
    
    /**
     *    Checks the mime type against a list
     *    of possible values.
     *    @param array $types      Possible mime types for a pass.
     *    @param string $message   Message to display.
     *    @return boolean          True if pass.
     *    @access public
     */
    function assertMime($types, $message = '%s') {
        $types = (is_array($types) ? $types : array($types));
        $type = $this->_browser->getMimeType();
        $message = sprintf($message, "Expecting mime type in [" .
                implode(", ", $types) . "] got [$type]");
        return $this->assertTrue(in_array($type, $types), $message);
    }
    
    /**
     *    Attempt to match the authentication type within
     *    the security realm we are currently matching.
     *    @param string $authentication   Usually basic.
     *    @param string $message          Message to display.
     *    @return boolean                 True if pass.
     *    @access public
     */
    function assertAuthentication($authentication = false, $message = '%s') {
        if (! $authentication) {
            $message = sprintf($message, "Expected any authentication type, got [" .
                    $this->_browser->getAuthentication() . "]");
            return $this->assertTrue(
                    $this->_browser->getAuthentication(),
                    $message);
        } else {
            $message = sprintf($message, "Expected authentication [$authentication] got [" .
                    $this->_browser->getAuthentication() . "]");
            return $this->assertTrue(
                    strtolower($this->_browser->getAuthentication()) == strtolower($authentication),
                    $message);
        }
    }
    
    /**
     *    Checks that no authentication is necessary to view
     *    the desired page.
     *    @param string $message     Message to display.
     *    @return boolean            True if pass.
     *    @access public
     */
    function assertNoAuthentication($message = '%s') {
        $message = sprintf($message, "Expected no authentication type, got [" .
                $this->_browser->getAuthentication() . "]");
        return $this->assertFalse($this->_browser->getAuthentication(), $message);
    }
    
    /**
     *    Attempts to match the current security realm.
     *    @param string $realm     Name of security realm.
     *    @param string $message   Message to display.
     *    @return boolean          True if pass.
     *    @access public
     */
    function assertRealm($realm, $message = '%s') {
        if (! SimpleExpectation::isExpectation($realm)) {
            $realm = new EqualExpectation($realm);
        }
        return $this->assert(
                $realm,
                $this->_browser->getRealm(),
                "Expected realm -> $message");
    }
    
    /**
     *    Checks each header line for the required value. If no
     *    value is given then only an existence check is made.
     *    @param string $header    Case insensitive header name.
     *    @param mixed $value      Case sensitive trimmed string to
     *                             match against. An expectation object
     *                             can be used for pattern matching.
     *    @return boolean          True if pass.
     *    @access public
     */
    function assertHeader($header, $value = false, $message = '%s') {
        return $this->assert(
                new HttpHeaderExpectation($header, $value),
                $this->_browser->getHeaders(),
                $message);
    }
        
    /**
     *    @deprecated
     */
    function assertHeaderPattern($header, $pattern, $message = '%s') {
        return $this->assert(
                new HttpHeaderExpectation($header, new PatternExpectation($pattern)),
                $this->_browser->getHeaders(),
                $message);
    }

    /**
     *    Confirms that the header type has not been received.
     *    Only the landing page is checked. If you want to check
     *    redirect pages, then you should limit redirects so
     *    as to capture the page you want.
     *    @param string $header    Case insensitive header name.
     *    @return boolean          True if pass.
     *    @access public
     */
    function assertNoHeader($header, $message = '%s') {
        return $this->assert(
                new NoHttpHeaderExpectation($header),
                $this->_browser->getHeaders(),
                $message);
    }
        
    /**
     *    @deprecated
     */
    function assertNoUnwantedHeader($header, $message = '%s') {
        return $this->assertNoHeader($header, $message);
    }
    
    /**
     *    Tests the text between the title tags.
     *    @param string/SimpleExpectation $title    Expected title.
     *    @param string $message                    Message to display.
     *    @return boolean                           True if pass.
     *    @access public
     */
    function assertTitle($title = false, $message = '%s') {
        if (! SimpleExpectation::isExpectation($title)) {
            $title = new EqualExpectation($title);
        }
        return $this->assert($title, $this->_browser->getTitle(), $message);
    }
    
    /**
     *    Will trigger a pass if the text is found in the plain
     *    text form of the page.
     *    @param string $text       Text to look for.
     *    @param string $message    Message to display.
     *    @return boolean           True if pass.
     *    @access public
     */
    function assertText($text, $message = '%s') {
        return $this->assert(
                new TextExpectation($text),
                $this->_browser->getContentAsText(),
                $message);
    }
    
    /**
     *    @deprecated
     */
    function assertWantedText($text, $message = '%s') {
        return $this->assertText($text, $message);
    }
    
    /**
     *    Will trigger a pass if the text is not found in the plain
     *    text form of the page.
     *    @param string $text       Text to look for.
     *    @param string $message    Message to display.
     *    @return boolean           True if pass.
     *    @access public
     */
    function assertNoText($text, $message = '%s') {
        return $this->assert(
                new NoTextExpectation($text),
                $this->_browser->getContentAsText(),
                $message);
    }
    
    /**
     *    @deprecated
     */
    function assertNoUnwantedText($text, $message = '%s') {
        return $this->assertNoText($text, $message);
    }
    
    /**
     *    Will trigger a pass if the Perl regex pattern
     *    is found in the raw content.
     *    @param string $pattern    Perl regex to look for including
     *                              the regex delimiters.
     *    @param string $message    Message to display.
     *    @return boolean           True if pass.
     *    @access public
     */
    function assertPattern($pattern, $message = '%s') {
        return $this->assert(
                new PatternExpectation($pattern),
                $this->_browser->getContent(),
                $message);
    }
    
    /**
     *    @deprecated
     */
    function assertWantedPattern($pattern, $message = '%s') {
        return $this->assertPattern($pattern, $message);
    }
    
    /**
     *    Will trigger a pass if the perl regex pattern
     *    is not present in raw content.
     *    @param string $pattern    Perl regex to look for including
     *                              the regex delimiters.
     *    @param string $message    Message to display.
     *    @return boolean           True if pass.
     *    @access public
     */
    function assertNoPattern($pattern, $message = '%s') {
        return $this->assert(
                new NoPatternExpectation($pattern),
                $this->_browser->getContent(),
                $message);
    }
    
    /**
     *    @deprecated
     */
    function assertNoUnwantedPattern($pattern, $message = '%s') {
        return $this->assertNoPattern($pattern, $message);
    }
    
    /**
     *    Checks that a cookie is set for the current page
     *    and optionally checks the value.
     *    @param string $name        Name of cookie to test.
     *    @param string $expected    Expected value as a string or
     *                               false if any value will do.
     *    @param string $message     Message to display.
     *    @return boolean            True if pass.
     *    @access public
     */
    function assertCookie($name, $expected = false, $message = '%s') {
        $value = $this->getCookie($name);
        if (! $expected) {
            return $this->assertTrue(
                    $value,
                    sprintf($message, "Expecting cookie [$name]"));
        }
        if (! SimpleExpectation::isExpectation($expected)) {
            $expected = new EqualExpectation($expected);
        }
        return $this->assert($expected, $value, "Expecting cookie [$name] -> $message");
    }
    
    /**
     *    Checks that no cookie is present or that it has
     *    been successfully cleared.
     *    @param string $name        Name of cookie to test.
     *    @param string $message     Message to display.
     *    @return boolean            True if pass.
     *    @access public
     */
    function assertNoCookie($name, $message = '%s') {
        return $this->assertTrue(
                $this->getCookie($name) === false,
                sprintf($message, "Not expecting cookie [$name]"));
    }

    /**
     *    Called from within the test methods to register
     *    passes and failures.
     *    @param boolean $result    Pass on true.
     *    @param string $message    Message to display describing
     *                              the test state.
     *    @return boolean           True on pass
     *    @access public
     */
    function assertTrue($result, $message = false) {
        return $this->assert(new TrueExpectation(), $result, $message);
    }

    /**
     *    Will be true on false and vice versa. False
     *    is the PHP definition of false, so that null,
     *    empty strings, zero and an empty array all count
     *    as false.
     *    @param boolean $result    Pass on false.
     *    @param string $message    Message to display.
     *    @return boolean           True on pass
     *    @access public
     */
    function assertFalse($result, $message = '%s') {
        return $this->assert(new FalseExpectation(), $result, $message);
    }
    
    /**
     *    Will trigger a pass if the two parameters have
     *    the same value only. Otherwise a fail. This
     *    is for testing hand extracted text, etc.
     *    @param mixed $first          Value to compare.
     *    @param mixed $second         Value to compare.
     *    @param string $message       Message to display.
     *    @return boolean              True on pass
     *    @access public
     */
    function assertEqual($first, $second, $message = '%s') {
        return $this->assert(
                new EqualExpectation($first),
                $second,
                $message);
    }
    
    /**
     *    Will trigger a pass if the two parameters have
     *    a different value. Otherwise a fail. This
     *    is for testing hand extracted text, etc.
     *    @param mixed $first           Value to compare.
     *    @param mixed $second          Value to compare.
     *    @param string $message        Message to display.
     *    @return boolean               True on pass
     *    @access public
     */
    function assertNotEqual($first, $second, $message = '%s') {
        return $this->assert(
                new NotEqualExpectation($first),
                $second,
                $message);
    }

    /**
     *    Uses a stack trace to find the line of an assertion.
     *    @return string           Line number of first assert*
     *                             method embedded in format string.
     *    @access public
     */
    function getAssertionLine() {
        $trace = new SimpleStackTrace(array('assert', 'click', 'pass', 'fail'));
        return $trace->traceMethod();
    }
}
?>