tests: Prefer PHPUnit's assertSame() when comparing empty strings

assertSame() is guaranteed to never do any magic type conversion.
This can be critical when accidentially comparing empty strings (a
value PHP considers to be "falsy") to false, 0, 0.0, null, and such.

Change-Id: I2e2685c5992cae252f629a68ffe1a049f2e5ed1b

tests/phpunit/MediaWikiCoversValidator.php

@@ -45,6 +45,6 @@ trait MediaWikiCoversValidator {
 			}
 		}
 
-		$this->assertEquals( '', $bad );
+		$this->assertSame( '', $bad );
 	}
 }

tests/phpunit/includes/FauxRequestTest.php

@@ -50,7 +50,7 @@ class FauxRequestTest extends PHPUnit\Framework\TestCase {
 	public function testGetText() {
 		$req = new FauxRequest( [ 'x' => 'Value' ] );
 		$this->assertEquals( 'Value', $req->getText( 'x' ) );
-		$this->assertEquals( '', $req->getText( 'z' ) );
+		$this->assertSame( '', $req->getText( 'z' ) );
 	}
 
 	/**
@@ -287,8 +287,8 @@ class FauxRequestTest extends PHPUnit\Framework\TestCase {
 	 */
 	public function testDummies() {
 		$req = new FauxRequest();
-		$this->assertEquals( '', $req->getRawQueryString() );
-		$this->assertEquals( '', $req->getRawPostString() );
-		$this->assertEquals( '', $req->getRawInput() );
+		$this->assertSame( '', $req->getRawQueryString() );
+		$this->assertSame( '', $req->getRawPostString() );
+		$this->assertSame( '', $req->getRawInput() );
 	}
 }

tests/phpunit/includes/HtmlTest.php

@@ -161,12 +161,12 @@ class HtmlTest extends MediaWikiTestCase {
 	 * @covers Html::expandAttributes
 	 */
 	public function testExpandAttributesForBooleans() {
-		$this->assertEquals(
+		$this->assertSame(
 			'',
 			Html::expandAttributes( [ 'selected' => false ] ),
 			'Boolean attributes do not generates output when value is false'
 		);
-		$this->assertEquals(
+		$this->assertSame(
 			'',
 			Html::expandAttributes( [ 'selected' => null ] ),
 			'Boolean attributes do not generates output when value is null'

tests/phpunit/includes/XmlTest.php

@@ -46,7 +46,7 @@ class XmlTest extends MediaWikiTestCase {
 		$this->assertNull( Xml::expandAttributes( null ),
 			'Converting a null list of attributes'
 		);
-		$this->assertEquals( '', Xml::expandAttributes( [] ),
+		$this->assertSame( '', Xml::expandAttributes( [] ),
 			'Converting an empty list of attributes'
 		);
 	}

tests/phpunit/includes/changes/EnhancedChangesListTest.php

@@ -76,7 +76,7 @@ class EnhancedChangesListTest extends MediaWikiLangTestCase {
 		$recentChange2 = $this->getEditChange( '20131103092253' );
 		$html = $enhancedChangesList->recentChangesLine( $recentChange2, false );
 
-		$this->assertEquals( '', $html );
+		$this->assertSame( '', $html );
 	}
 
 	public function testRecentChangesPrefix() {

tests/phpunit/includes/content/ContentHandlerTest.php

@@ -181,7 +181,7 @@ class ContentHandlerTest extends MediaWikiTestCase {
 		$content = null;
 
 		$text = ContentHandler::getContentText( $content );
-		$this->assertEquals( '', $text );
+		$this->assertSame( '', $text );
 	}
 
 	public static function dataGetContentText_TextContent() {

tests/phpunit/includes/content/UnknownContentHandlerTest.php

@@ -49,7 +49,7 @@ class UnknownContentHandlerTest extends MediaWikiLangTestCase {
 		$content = $handler->makeEmptyContent();
 
 		$this->assertTrue( $content->isEmpty() );
-		$this->assertEquals( '', $content->getData() );
+		$this->assertSame( '', $content->getData() );
 	}
 
 	public static function dataIsSupportedFormat() {

tests/phpunit/includes/content/UnknownContentTest.php

@@ -139,7 +139,7 @@ class UnknownContentTest extends MediaWikiLangTestCase {
 	public function testGetWikitextForTransclusion() {
 		$content = $this->newContent( 'hello world.' );
 
-		$this->assertEquals( '', $content->getWikitextForTransclusion() );
+		$this->assertFalse( $content->getWikitextForTransclusion() );
 	}
 
 	/**

tests/phpunit/includes/content/WikitextContentHandlerTest.php

@@ -64,7 +64,7 @@ class WikitextContentHandlerTest extends MediaWikiLangTestCase {
 		$content = $this->handler->makeEmptyContent();
 
 		$this->assertTrue( $content->isEmpty() );
-		$this->assertEquals( '', $content->getText() );
+		$this->assertSame( '', $content->getText() );
 	}
 
 	public static function dataIsSupportedFormat() {

tests/phpunit/includes/db/LBFactoryTest.php

@@ -475,17 +475,16 @@ class LBFactoryTest extends MediaWikiTestCase {
 		/** @var IMaintainableDatabase $db */
 		$db = $lb->getConnection( DB_MASTER, [], '' );
 
-		$this->assertEquals(
+		$this->assertSame(
 			'',
 			$db->getDomainId(),
 			'Null domain ID handle used'
 		);
-		$this->assertEquals(
-			'',
+		$this->assertNull(
 			$db->getDBname(),
 			'Null domain ID handle used'
 		);
-		$this->assertEquals(
+		$this->assertSame(
 			'',
 			$db->tablePrefix(),
 			'Main domain ID handle used; prefix is empty though'
@@ -555,7 +554,7 @@ class LBFactoryTest extends MediaWikiTestCase {
 		/** @var IMaintainableDatabase $db */
 		$db = $lb->getConnection( DB_MASTER, [], '' );
 
-		$this->assertEquals( '', $db->getDomainID(), "Null domain used" );
+		$this->assertSame( '', $db->getDomainID(), "Null domain used" );
 
 		$this->assertEquals(
 			$this->quoteTable( $db, 'page' ),

tests/phpunit/includes/filerepo/file/LocalFileTest.php

@@ -52,7 +52,7 @@ class LocalFileTest extends MediaWikiTestCase {
 	 * @covers File::getHashPath
 	 */
 	public function testGetHashPath() {
-		$this->assertEquals( '', $this->file_hl0->getHashPath() );
+		$this->assertSame( '', $this->file_hl0->getHashPath() );
 		$this->assertEquals( 'a/a2/', $this->file_hl2->getHashPath() );
 		$this->assertEquals( 'c/c4/', $this->file_lc->getHashPath() );
 	}

tests/phpunit/includes/http/HttpTest.php

@@ -14,7 +14,7 @@ class HttpTest extends MediaWikiTestCase {
 		$this->hideDeprecated( 'Http::getProxy' );
 
 		$this->setMwGlobals( 'wgHTTPProxy', false );
-		$this->assertEquals(
+		$this->assertSame(
 			'',
 			Http::getProxy(),
 			'default setting'

tests/phpunit/includes/linker/LinkRendererTest.php

@@ -168,7 +168,7 @@ class LinkRendererTest extends MediaWikiLangTestCase {
 
 		$linkRenderer = new LinkRenderer( $titleFormatter, $linkCache, $nsInfo );
 		$linkRenderer->setStubThreshold( 0 );
-		$this->assertEquals(
+		$this->assertSame(
 			'',
 			$linkRenderer->getLinkClasses( $foobarTitle )
 		);
@@ -186,7 +186,7 @@ class LinkRendererTest extends MediaWikiLangTestCase {
 		);
 
 		$linkRenderer->setStubThreshold( 20 );
-		$this->assertEquals(
+		$this->assertSame(
 			'',
 			$linkRenderer->getLinkClasses( $userTitle )
 		);

tests/phpunit/includes/resourceloader/ResourceLoaderTest.php

@@ -718,7 +718,7 @@ END
 		] );
 		$context = $this->getResourceLoaderContext( [], $rl );
 
-		$this->assertEquals(
+		$this->assertSame(
 			'',
 			$rl->getCombinedVersion( $context, [] ),
 			'empty list'

tests/phpunit/includes/site/SiteTest.php

@@ -222,7 +222,7 @@ class SiteTest extends MediaWikiTestCase {
 		$path = '//acme.com/'; // protocol-relative URL
 		$site->setPath( $type, $path );
 
-		$this->assertEquals( '', $site->getProtocol() );
+		$this->assertSame( '', $site->getProtocol() );
 	}
 
 	public static function provideGetPageUrl() {

tests/phpunit/languages/LanguageTest.php

@@ -1799,7 +1799,7 @@ class LanguageTest extends LanguageClassesTestCase {
 		$s = $lang->getMessageFromDB( 'word-separator' );
 		$c = $lang->getMessageFromDB( 'comma-separator' );
 
-		$this->assertEquals( '', $lang->listToText( [] ) );
+		$this->assertSame( '', $lang->listToText( [] ) );
 		$this->assertEquals( 'a', $lang->listToText( [ 'a' ] ) );
 		$this->assertEquals( "a{$and}{$s}b", $lang->listToText( [ 'a', 'b' ] ) );
 		$this->assertEquals( "a{$c}b{$and}{$s}c", $lang->listToText( [ 'a', 'b', 'c' ] ) );

tests/phpunit/maintenance/DumpTestCase.php

@@ -185,7 +185,7 @@ abstract class DumpTestCase extends MediaWikiLangTestCase {
 		// 2. Do the real output checking on our own.
 		$lines = explode( "\n", $this->getActualOutput() );
 		$this->assertGreaterThan( 1, count( $lines ), "Minimal lines of produced output" );
-		$this->assertEquals( '', array_pop( $lines ), "Output ends in LF" );
+		$this->assertSame( '', array_pop( $lines ), "Output ends in LF" );
 		$timestamp_re = "[0-9]{4}-[01][0-9]-[0-3][0-9] [0-2][0-9]:[0-5][0-9]:[0-6][0-9]";
 		foreach ( $lines as $line ) {
 			$this->assertRegExp(

tests/phpunit/unit/includes/password/PasswordFactoryTest.php

@@ -7,7 +7,7 @@ class PasswordFactoryTest extends MediaWikiUnitTestCase {
 	public function testConstruct() {
 		$pf = new PasswordFactory();
 		$this->assertEquals( [ '' ], array_keys( $pf->getTypes() ) );
-		$this->assertEquals( '', $pf->getDefaultType() );
+		$this->assertSame( '', $pf->getDefaultType() );
 
 		$pf = new PasswordFactory( [
 			'foo' => [ 'class' => 'FooPassword' ],