tests/phpunit/MediaWikiTestCase.php

   1 <?php
   2
   3 abstract class MediaWikiTestCase extends PHPUnit_Framework_TestCase {
   4         public $suite;
   5         public $regex = '';
   6         public $runDisabled = false;
   7
   8         /**
   9          * @var Array of TestUser
  10          */
  11         public static $users;
  12
  13         /**
  14          * @var DatabaseBase
  15          */
  16         protected $db;
  17         protected $oldTablePrefix;
  18         protected $useTemporaryTables = true;
  19         protected $reuseDB = false;
  20         protected $tablesUsed = array(); // tables with data
  21
  22         private static $dbSetup = false;
  23
  24         /**
  25          * Holds the paths of temporary files/directories created through getNewTempFile,
  26          * and getNewTempDirectory
  27          *
  28          * @var array
  29          */
  30         private $tmpfiles = array();
  31
  32         /**
  33          * Holds original values of MediaWiki configuration settings
  34          * to be restored in tearDown().
  35          * See also setMwGlobal().
  36          * @var array
  37          */
  38         private $mwGlobals = array();
  39
  40         /**
  41          * Table name prefixes. Oracle likes it shorter.
  42          */
  43         const DB_PREFIX = 'unittest_';
  44         const ORA_DB_PREFIX = 'ut_';
  45
  46         protected $supportedDBs = array(
  47                 'mysql',
  48                 'sqlite',
  49                 'postgres',
  50                 'oracle'
  51         );
  52
  53         function  __construct( $name = null, array $data = array(), $dataName = '' ) {
  54                 parent::__construct( $name, $data, $dataName );
  55
  56                 $this->backupGlobals = false;
  57                 $this->backupStaticAttributes = false;
  58         }
  59
  60         function run( PHPUnit_Framework_TestResult $result = NULL ) {
  61                 /* Some functions require some kind of caching, and will end up using the db,
  62                  * which we can't allow, as that would open a new connection for mysql.
  63                  * Replace with a HashBag. They would not be going to persist anyway.
  64                  */
  65                 ObjectCache::$instances[CACHE_DB] = new HashBagOStuff;
  66
  67                 if( $this->needsDB() ) {
  68                         global $wgDBprefix;
  69
  70                         $this->useTemporaryTables = !$this->getCliArg( 'use-normal-tables' );
  71                         $this->reuseDB = $this->getCliArg('reuse-db');
  72
  73                         $this->db = wfGetDB( DB_MASTER );
  74
  75                         $this->checkDbIsSupported();
  76
  77                         $this->oldTablePrefix = $wgDBprefix;
  78
  79                         if( !self::$dbSetup ) {
  80                                 $this->initDB();
  81                                 self::$dbSetup = true;
  82                         }
  83
  84                         $this->addCoreDBData();
  85                         $this->addDBData();
  86
  87                         parent::run( $result );
  88
  89                         $this->resetDB();
  90                 } else {
  91                         parent::run( $result );
  92                 }
  93         }
  94
  95         /**
  96          * obtains a new temporary file name
  97          *
  98          * The obtained filename is enlisted to be removed upon tearDown
  99          *
 100          * @returns string: absolute name of the temporary file
 101          */
 102         protected function getNewTempFile() {
 103                 $fname = tempnam( wfTempDir(), 'MW_PHPUnit_' . get_class( $this ) . '_' );
 104                 $this->tmpfiles[] = $fname;
 105                 return $fname;
 106         }
 107
 108         /**
 109          * obtains a new temporary directory
 110          *
 111          * The obtained directory is enlisted to be removed (recursively with all its contained
 112          * files) upon tearDown.
 113          *
 114          * @returns string: absolute name of the temporary directory
 115          */
 116         protected function getNewTempDirectory() {
 117                 // Starting of with a temporary /file/.
 118                 $fname = $this->getNewTempFile();
 119
 120                 // Converting the temporary /file/ to a /directory/
 121                 //
 122                 // The following is not atomic, but at least we now have a single place,
 123                 // where temporary directory creation is bundled and can be improved
 124                 unlink( $fname );
 125                 $this->assertTrue( wfMkdirParents( $fname ) );
 126                 return $fname;
 127         }
 128
 129         /**
 130          * setUp and tearDown should (where significant)
 131          * happen in reverse order.
 132          */
 133         protected function setUp() {
 134                 parent::setUp();
 135
 136                 /*
 137                 //@todo: global variables to restore for *every* test
 138                 array(
 139                         'wgLang',
 140                         'wgContLang',
 141                         'wgLanguageCode',
 142                         'wgUser',
 143                         'wgTitle',
 144                 );
 145                 */
 146
 147                 // Cleaning up temporary files
 148                 foreach ( $this->tmpfiles as $fname ) {
 149                         if ( is_file( $fname ) || ( is_link( $fname ) ) ) {
 150                                 unlink( $fname );
 151                         } elseif ( is_dir( $fname ) ) {
 152                                 wfRecursiveRemoveDir( $fname );
 153                         }
 154                 }
 155
 156                 // Clean up open transactions
 157                 if ( $this->needsDB() && $this->db ) {
 158                         while( $this->db->trxLevel() > 0 ) {
 159                                 $this->db->rollback();
 160                         }
 161                 }
 162         }
 163
 164         protected function tearDown() {
 165                 // Cleaning up temporary files
 166                 foreach ( $this->tmpfiles as $fname ) {
 167                         if ( is_file( $fname ) || ( is_link( $fname ) ) ) {
 168                                 unlink( $fname );
 169                         } elseif ( is_dir( $fname ) ) {
 170                                 wfRecursiveRemoveDir( $fname );
 171                         }
 172                 }
 173
 174                 // Clean up open transactions
 175                 if ( $this->needsDB() && $this->db ) {
 176                         while( $this->db->trxLevel() > 0 ) {
 177                                 $this->db->rollback();
 178                         }
 179                 }
 180
 181                 // Restore mw globals
 182                 foreach ( $this->mwGlobals as $key => $value ) {
 183                         $GLOBALS[$key] = $value;
 184                 }
 185                 $this->mwGlobals = array();
 186
 187                 parent::tearDown();
 188         }
 189
 190         /**
 191          * Individual test functions may override globals (either directly or through this
 192          * setMwGlobals() function), however one must call this method at least once for
 193          * each key within the setUp().
 194          * That way the key is added to the array of globals that will be reset afterwards
 195          * in the tearDown(). And, equally important, that way all other tests are executed
 196          * with the same settings (instead of using the unreliable local settings for most
 197          * tests and fix it only for some tests).
 198          *
 199          * @example
 200          * <code>
 201          *     protected function setUp() {
 202          *         $this->setMwGlobals( 'wgRestrictStuff', true );
 203          *     }
 204          *
 205          *     function testFoo() {}
 206          *
 207          *     function testBar() {}
 208          *         $this->assertTrue( self::getX()->doStuff() );
 209          *
 210          *         $this->setMwGlobals( 'wgRestrictStuff', false );
 211          *         $this->assertTrue( self::getX()->doStuff() );
 212          *     }
 213          *
 214          *     function testQuux() {}
 215          * </code>
 216          *
 217          * @param array|string $pairs Key to the global variable, or an array
 218          *  of key/value pairs.
 219          * @param mixed $value Value to set the global to (ignored
 220          *  if an array is given as first argument).
 221          */
 222         protected function setMwGlobals( $pairs, $value = null ) {
 223
 224                 // Normalize (string, value) to an array
 225                 if( is_string( $pairs ) ) {
 226                         $pairs = array( $pairs => $value );
 227                 }
 228
 229                 foreach ( $pairs as $key => $value ) {
 230                         // NOTE: make sure we only save the global once or a second call to
 231                         // setMwGlobals() on the same global would override the original
 232                         // value.
 233                         if ( !array_key_exists( $key, $this->mwGlobals ) ) {
 234                                 $this->mwGlobals[$key] = $GLOBALS[$key];
 235                         }
 236
 237                         // Override the global
 238                         $GLOBALS[$key] = $value;
 239                 }
 240         }
 241
 242         /**
 243          * Merges the given values into a MW global array variable.
 244          * Useful for setting some entries in a configuration array, instead of
 245          * setting the entire array.
 246          *
 247          * @param String $name The name of the global, as in wgFooBar
 248          * @param Array $values The array containing the entries to set in that global
 249          *
 250          * @throws MWException if the designated global is not an array.
 251          */
 252         protected function mergeMwGlobalArrayValue( $name, $values ) {
 253                 if ( !isset( $GLOBALS[$name] ) ) {
 254                         $merged = $values;
 255                 } else {
 256                         if ( !is_array( $GLOBALS[$name] ) ) {
 257                                 throw new MWException( "MW global $name is not an array." );
 258                         }
 259
 260                         //NOTE: do not use array_merge, it screws up for numeric keys.
 261                         $merged = $GLOBALS[$name];
 262                         foreach ( $values as $k => $v ) {
 263                                 $merged[$k] = $v;
 264                         }
 265                 }
 266
 267                 $this->setMwGlobals( $name, $merged );
 268         }
 269
 270         function dbPrefix() {
 271                 return $this->db->getType() == 'oracle' ? self::ORA_DB_PREFIX : self::DB_PREFIX;
 272         }
 273
 274         function needsDB() {
 275                 # if the test says it uses database tables, it needs the database
 276                 if ( $this->tablesUsed ) {
 277                         return true;
 278                 }
 279
 280                 # if the test says it belongs to the Database group, it needs the database
 281                 $rc = new ReflectionClass( $this );
 282                 if ( preg_match( '/@group +Database/im', $rc->getDocComment() ) ) {
 283                         return true;
 284                 }
 285
 286                 return false;
 287         }
 288
 289         /**
 290          * Stub. If a test needs to add additional data to the database, it should
 291          * implement this method and do so
 292          */
 293         function addDBData() {}
 294
 295         private function addCoreDBData() {
 296                 # disabled for performance
 297                 #$this->tablesUsed[] = 'page';
 298                 #$this->tablesUsed[] = 'revision';
 299
 300                 if ( $this->db->getType() == 'oracle' ) {
 301
 302                         # Insert 0 user to prevent FK violations
 303                         # Anonymous user
 304                         $this->db->insert( 'user', array(
 305                                 'user_id'               => 0,
 306                                 'user_name'     => 'Anonymous' ), __METHOD__, array( 'IGNORE' ) );
 307
 308                         # Insert 0 page to prevent FK violations
 309                         # Blank page
 310                         $this->db->insert( 'page', array(
 311                                 'page_id' => 0,
 312                                 'page_namespace' => 0,
 313                                 'page_title' => ' ',
 314                                 'page_restrictions' => NULL,
 315                                 'page_counter' => 0,
 316                                 'page_is_redirect' => 0,
 317                                 'page_is_new' => 0,
 318                                 'page_random' => 0,
 319                                 'page_touched' => $this->db->timestamp(),
 320                                 'page_latest' => 0,
 321                                 'page_len' => 0 ), __METHOD__, array( 'IGNORE' ) );
 322
 323                 }
 324
 325                 User::resetIdByNameCache();
 326
 327                 //Make sysop user
 328                 $user = User::newFromName( 'UTSysop' );
 329
 330                 if ( $user->idForName() == 0 ) {
 331                         $user->addToDatabase();
 332                         $user->setPassword( 'UTSysopPassword' );
 333
 334                         $user->addGroup( 'sysop' );
 335                         $user->addGroup( 'bureaucrat' );
 336                         $user->saveSettings();
 337                 }
 338
 339
 340                 //Make 1 page with 1 revision
 341                 $page = WikiPage::factory( Title::newFromText( 'UTPage' ) );
 342                 if ( !$page->getId() == 0 ) {
 343                         $page->doEditContent(
 344                                 new WikitextContent( 'UTContent' ),
 345                                 'UTPageSummary',
 346                                 EDIT_NEW,
 347                                 false,
 348                                 User::newFromName( 'UTSysop' ) );
 349                 }
 350         }
 351
 352         private function initDB() {
 353                 global $wgDBprefix;
 354                 if ( $wgDBprefix === $this->dbPrefix() ) {
 355                         throw new MWException( 'Cannot run unit tests, the database prefix is already "unittest_"' );
 356                 }
 357
 358                 $tablesCloned = $this->listTables();
 359                 $dbClone = new CloneDatabase( $this->db, $tablesCloned, $this->dbPrefix() );
 360                 $dbClone->useTemporaryTables( $this->useTemporaryTables );
 361
 362                 if ( ( $this->db->getType() == 'oracle' || !$this->useTemporaryTables ) && $this->reuseDB ) {
 363                         CloneDatabase::changePrefix( $this->dbPrefix() );
 364                         $this->resetDB();
 365                         return;
 366                 } else {
 367                         $dbClone->cloneTableStructure();
 368                 }
 369
 370                 if ( $this->db->getType() == 'oracle' ) {
 371                         $this->db->query( 'BEGIN FILL_WIKI_INFO; END;' );
 372                 }
 373         }
 374
 375         /**
 376          * Empty all tables so they can be repopulated for tests
 377          */
 378         private function resetDB() {
 379                 if( $this->db ) {
 380                         if ( $this->db->getType() == 'oracle' )  {
 381                                 if ( $this->useTemporaryTables ) {
 382                                         wfGetLB()->closeAll();
 383                                         $this->db = wfGetDB( DB_MASTER );
 384                                 } else {
 385                                         foreach( $this->tablesUsed as $tbl ) {
 386                                                 if( $tbl == 'interwiki') continue;
 387                                                 $this->db->query( 'TRUNCATE TABLE '.$this->db->tableName($tbl), __METHOD__ );
 388                                         }
 389                                 }
 390                         } else {
 391                                 foreach( $this->tablesUsed as $tbl ) {
 392                                         if( $tbl == 'interwiki' || $tbl == 'user' ) continue;
 393                                         $this->db->delete( $tbl, '*', __METHOD__ );
 394                                 }
 395                         }
 396                 }
 397         }
 398
 399         function __call( $func, $args ) {
 400                 static $compatibility = array(
 401                         'assertInternalType' => 'assertType',
 402                         'assertNotInternalType' => 'assertNotType',
 403                         'assertInstanceOf' => 'assertType',
 404                         'assertEmpty' => 'assertEmpty2',
 405                 );
 406
 407                 if ( method_exists( $this->suite, $func ) ) {
 408                         return call_user_func_array( array( $this->suite, $func ), $args);
 409                 } elseif ( isset( $compatibility[$func] ) ) {
 410                         return call_user_func_array( array( $this, $compatibility[$func] ), $args);
 411                 } else {
 412                         throw new MWException( "Called non-existant $func method on "
 413                                 . get_class( $this ) );
 414                 }
 415         }
 416
 417         private function assertEmpty2( $value, $msg ) {
 418                 return $this->assertTrue( $value == '', $msg );
 419         }
 420
 421         static private function unprefixTable( $tableName ) {
 422                 global $wgDBprefix;
 423                 return substr( $tableName, strlen( $wgDBprefix ) );
 424         }
 425
 426         static private function isNotUnittest( $table ) {
 427                 return strpos( $table, 'unittest_' ) !== 0;
 428         }
 429
 430         protected function listTables() {
 431                 global $wgDBprefix;
 432
 433                 $tables = $this->db->listTables( $wgDBprefix, __METHOD__ );
 434                 $tables = array_map( array( __CLASS__, 'unprefixTable' ), $tables );
 435
 436                 // Don't duplicate test tables from the previous fataled run
 437                 $tables = array_filter( $tables, array( __CLASS__, 'isNotUnittest' ) );
 438
 439                 if ( $this->db->getType() == 'sqlite' ) {
 440                         $tables = array_flip( $tables );
 441                         // these are subtables of searchindex and don't need to be duped/dropped separately
 442                         unset( $tables['searchindex_content'] );
 443                         unset( $tables['searchindex_segdir'] );
 444                         unset( $tables['searchindex_segments'] );
 445                         $tables = array_flip( $tables );
 446                 }
 447                 return $tables;
 448         }
 449
 450         protected function checkDbIsSupported() {
 451                 if( !in_array( $this->db->getType(), $this->supportedDBs ) ) {
 452                         throw new MWException( $this->db->getType() . " is not currently supported for unit testing." );
 453                 }
 454         }
 455
 456         public function getCliArg( $offset ) {
 457
 458                 if( isset( MediaWikiPHPUnitCommand::$additionalOptions[$offset] ) ) {
 459                         return MediaWikiPHPUnitCommand::$additionalOptions[$offset];
 460                 }
 461
 462         }
 463
 464         public function setCliArg( $offset, $value ) {
 465
 466                 MediaWikiPHPUnitCommand::$additionalOptions[$offset] = $value;
 467
 468         }
 469
 470         /**
 471          * Don't throw a warning if $function is deprecated and called later
 472          *
 473          * @param $function String
 474          * @return null
 475          */
 476         function hideDeprecated( $function ) {
 477                 wfSuppressWarnings();
 478                 wfDeprecated( $function );
 479                 wfRestoreWarnings();
 480         }
 481
 482         /**
 483          * Asserts that the given database query yields the rows given by $expectedRows.
 484          * The expected rows should be given as indexed (not associative) arrays, with
 485          * the values given in the order of the columns in the $fields parameter.
 486          * Note that the rows are sorted by the columns given in $fields.
 487          *
 488          * @since 1.20
 489          *
 490          * @param $table String|Array the table(s) to query
 491          * @param $fields String|Array the columns to include in the result (and to sort by)
 492          * @param $condition String|Array "where" condition(s)
 493          * @param $expectedRows Array - an array of arrays giving the expected rows.
 494          *
 495          * @throws MWException if this test cases's needsDB() method doesn't return true.
 496          *         Test cases can use "@group Database" to enable database test support,
 497          *         or list the tables under testing in $this->tablesUsed, or override the
 498          *         needsDB() method.
 499          */
 500         protected function assertSelect( $table, $fields, $condition, array $expectedRows ) {
 501                 if ( !$this->needsDB() ) {
 502                         throw new MWException( 'When testing database state, the test cases\'s needDB()' .
 503                                 ' method should return true. Use @group Database or $this->tablesUsed.');
 504                 }
 505
 506                 $db = wfGetDB( DB_SLAVE );
 507
 508                 $res = $db->select( $table, $fields, $condition, wfGetCaller(), array( 'ORDER BY' => $fields ) );
 509                 $this->assertNotEmpty( $res, "query failed: " . $db->lastError() );
 510
 511                 $i = 0;
 512
 513                 foreach ( $expectedRows as $expected ) {
 514                         $r = $res->fetchRow();
 515                         self::stripStringKeys( $r );
 516
 517                         $i += 1;
 518                         $this->assertNotEmpty( $r, "row #$i missing" );
 519
 520                         $this->assertEquals( $expected, $r, "row #$i mismatches" );
 521                 }
 522
 523                 $r = $res->fetchRow();
 524                 self::stripStringKeys( $r );
 525
 526                 $this->assertFalse( $r, "found extra row (after #$i)" );
 527         }
 528
 529         /**
 530          * Utility method taking an array of elements and wrapping
 531          * each element in it's own array. Useful for data providers
 532          * that only return a single argument.
 533          *
 534          * @since 1.20
 535          *
 536          * @param array $elements
 537          *
 538          * @return array
 539          */
 540         protected function arrayWrap( array $elements ) {
 541                 return array_map(
 542                         function( $element ) {
 543                                 return array( $element );
 544                         },
 545                         $elements
 546                 );
 547         }
 548
 549         /**
 550          * Assert that two arrays are equal. By default this means that both arrays need to hold
 551          * the same set of values. Using additional arguments, order and associated key can also
 552          * be set as relevant.
 553          *
 554          * @since 1.20
 555          *
 556          * @param array $expected
 557          * @param array $actual
 558          * @param boolean $ordered If the order of the values should match
 559          * @param boolean $named If the keys should match
 560          */
 561         protected function assertArrayEquals( array $expected, array $actual, $ordered = false, $named = false ) {
 562                 if ( !$ordered ) {
 563                         $this->objectAssociativeSort( $expected );
 564                         $this->objectAssociativeSort( $actual );
 565                 }
 566
 567                 if ( !$named ) {
 568                         $expected = array_values( $expected );
 569                         $actual = array_values( $actual );
 570                 }
 571
 572                 call_user_func_array(
 573                         array( $this, 'assertEquals' ),
 574                         array_merge( array( $expected, $actual ), array_slice( func_get_args(), 4 ) )
 575                 );
 576         }
 577
 578         /**
 579          * Put each HTML element on its own line and then equals() the results
 580          *
 581          * Use for nicely formatting of PHPUnit diff output when comparing very
 582          * simple HTML
 583          *
 584          * @since 1.20
 585          *
 586          * @param String $expected HTML on oneline
 587          * @param String $actual HTML on oneline
 588          * @param String $msg Optional message
 589          */
 590         protected function assertHTMLEquals( $expected, $actual, $msg='' ) {
 591                 $expected = str_replace( '>', ">\n", $expected );
 592                 $actual   = str_replace( '>', ">\n", $actual   );
 593
 594                 $this->assertEquals( $expected, $actual, $msg );
 595         }
 596
 597         /**
 598          * Does an associative sort that works for objects.
 599          *
 600          * @since 1.20
 601          *
 602          * @param array $array
 603          */
 604         protected function objectAssociativeSort( array &$array ) {
 605                 uasort(
 606                         $array,
 607                         function( $a, $b ) {
 608                                 return serialize( $a ) > serialize( $b ) ? 1 : -1;
 609                         }
 610                 );
 611         }
 612
 613         /**
 614          * Utility function for eliminating all string keys from an array.
 615          * Useful to turn a database result row as returned by fetchRow() into
 616          * a pure indexed array.
 617          *
 618          * @since 1.20
 619          *
 620          * @param $r mixed the array to remove string keys from.
 621          */
 622         protected static function stripStringKeys( &$r ) {
 623                 if ( !is_array( $r ) ) {
 624                         return;
 625                 }
 626
 627                 foreach ( $r as $k => $v ) {
 628                         if ( is_string( $k ) ) {
 629                                 unset( $r[$k] );
 630                         }
 631                 }
 632         }
 633
 634         /**
 635          * Asserts that the provided variable is of the specified
 636          * internal type or equals the $value argument. This is useful
 637          * for testing return types of functions that return a certain
 638          * type or *value* when not set or on error.
 639          *
 640          * @since 1.20
 641          *
 642          * @param string $type
 643          * @param mixed $actual
 644          * @param mixed $value
 645          * @param string $message
 646          */
 647         protected function assertTypeOrValue( $type, $actual, $value = false, $message = '' ) {
 648                 if ( $actual === $value ) {
 649                         $this->assertTrue( true, $message );
 650                 }
 651                 else {
 652                         $this->assertType( $type, $actual, $message );
 653                 }
 654         }
 655
 656         /**
 657          * Asserts the type of the provided value. This can be either
 658          * in internal type such as boolean or integer, or a class or
 659          * interface the value extends or implements.
 660          *
 661          * @since 1.20
 662          *
 663          * @param string $type
 664          * @param mixed $actual
 665          * @param string $message
 666          */
 667         protected function assertType( $type, $actual, $message = '' ) {
 668                 if ( class_exists( $type ) || interface_exists( $type ) ) {
 669                         $this->assertInstanceOf( $type, $actual, $message );
 670                 }
 671                 else {
 672                         $this->assertInternalType( $type, $actual, $message );
 673                 }
 674         }
 675
 676         /**
 677          * Returns true iff the given namespace defaults to Wikitext
 678          * according to $wgNamespaceContentModels
 679          *
 680          * @param int $ns The namespace ID to check
 681          *
 682          * @return bool
 683          * @since 1.21
 684          */
 685         protected function isWikitextNS( $ns ) {
 686                 global $wgNamespaceContentModels;
 687
 688                 if ( isset( $wgNamespaceContentModels[$ns] ) ) {
 689                         return $wgNamespaceContentModels[$ns] === CONTENT_MODEL_WIKITEXT;
 690                 }
 691
 692                 return true;
 693         }
 694
 695         /**
 696          * Returns the ID of a namespace that defaults to Wikitext.
 697          * Throws an MWException if there is none.
 698          *
 699          * @return int the ID of the wikitext Namespace
 700          * @since 1.21
 701          */
 702         protected function getDefaultWikitextNS() {
 703                 global $wgNamespaceContentModels;
 704
 705                 static $wikitextNS = null; // this is not going to change
 706                 if ( $wikitextNS !== null ) {
 707                         return $wikitextNS;
 708                 }
 709
 710                 // quickly short out on most common case:
 711                 if ( !isset( $wgNamespaceContentModels[NS_MAIN] ) ) {
 712                         return NS_MAIN;
 713                 }
 714
 715                 // NOTE: prefer content namespaces
 716                 $namespaces = array_unique( array_merge(
 717                         MWNamespace::getContentNamespaces(),
 718                         array( NS_MAIN, NS_HELP, NS_PROJECT ), // prefer these
 719                         MWNamespace::getValidNamespaces()
 720                 ) );
 721
 722                 $namespaces = array_diff( $namespaces, array(
 723                         NS_FILE, NS_CATEGORY, NS_MEDIAWIKI, NS_USER // don't mess with magic namespaces
 724                 ));
 725
 726                 $talk = array_filter( $namespaces, function ( $ns ) {
 727                         return MWNamespace::isTalk( $ns );
 728                 } );
 729
 730                 // prefer non-talk pages
 731                 $namespaces = array_diff( $namespaces, $talk );
 732                 $namespaces = array_merge( $namespaces, $talk );
 733
 734                 // check default content model of each namespace
 735                 foreach ( $namespaces as $ns ) {
 736                         if ( !isset( $wgNamespaceContentModels[$ns] ) ||
 737                                 $wgNamespaceContentModels[$ns] === CONTENT_MODEL_WIKITEXT ) {
 738
 739                                 $wikitextNS = $ns;
 740                                 return $wikitextNS;
 741                         }
 742                 }
 743
 744                 // give up
 745                 // @todo: Inside a test, we could skip the test as incomplete.
 746                 //        But frequently, this is used in fixture setup.
 747                 throw new MWException( "No namespace defaults to wikitext!" );
 748         }
 749 }