Always return a string from Language::formatNum()

It says it returns a string, and so it should.

Bug: T182277
Change-Id: Ic68c65c634c2557a1d07281623cd6c971b000323

1 files changed, 27 insertions, 0 deletions

diff --git a/tests/phpunit/languages/LanguageTest.php b/tests/phpunit/languages/LanguageTest.php
index cd52366fca82..e39f57ea997b 100644
--- a/tests/phpunit/languages/LanguageTest.php
+++ b/tests/phpunit/languages/LanguageTest.php
@@ -1630,6 +1630,33 @@ class LanguageTest extends LanguageClassesTestCase {
 	}
 
 	/**
+	 * @dataProvider testFormatNumProvider
+	 * @covers Language::formatNum
+	 */
+	public function testFormatNum(
+		$translateNumerals, $langCode, $number, $nocommafy, $expected
+	) {
+		$this->setMwGlobals( [ 'wgTranslateNumerals' => $translateNumerals ] );
+		$lang = Language::factory( $langCode );
+		$formattedNum = $lang->formatNum( $number, $nocommafy );
+		$this->assertType( 'string', $formattedNum );
+		$this->assertEquals( $expected, $formattedNum );
+	}
+
+	public function testFormatNumProvider() {
+		return [
+			[ true, 'en', 100, false, '100' ],
+			[ true, 'en', 101, true, '101' ],
+			[ false, 'en', 103, false, '103' ],
+			[ false, 'en', 104, true, '104' ],
+			[ true, 'en', '105', false, '105' ],
+			[ true, 'en', '106', true, '106' ],
+			[ false, 'en', '107', false, '107' ],
+			[ false, 'en', '108', true, '108' ],
+		];
+	}
+
+	/**
 	 * @dataProvider parseFormattedNumberProvider
 	 */
 	public function testParseFormattedNumber( $langCode, $number ) {