Add tests for ::is_file().

Author: costdev

tests/phpunit/tests/filesystem/wpFilesystemDirect/isFile.php

@@ -0,0 +1,44 @@
+<?php
+/**
+ * Tests for the WP_Filesystem_Direct::is_file() method.
+ *
+ * @package WordPress
+ */
+
+require_once __DIR__ . '/base.php';
+
+/**
+ * @group admin
+ * @group filesystem
+ * @group filesystem-direct
+ *
+ * @covers WP_Filesystem_Direct::is_file
+ */
+class Tests_Filesystem_WpFilesystemDirect_IsFile extends WP_Filesystem_Direct_UnitTestCase {
+
+	/**
+	 * Tests that `WP_Filesystem_Direct::is_file()` returns the correct value
+	 * when checking whether a path is a file.
+	 *
+	 * @ticket 57774
+	 *
+	 * @dataProvider data_paths_that_exist
+	 * @dataProvider data_paths_that_do_not_exist
+	 *
+	 * @param string $path     The path to check.
+	 * @param bool   $expected The expected result.
+	 * @param string $type     The type of resource. Accepts 'f' or 'd'.
+	 *                         Used to invert $expected due to data provider setup.
+	 */
+	public function test_should_determine_if_a_path_is_a_file( $path, $expected, $type ) {
+		/*
+		 * Invert the data provider's $expected value for
+		 * directories with empty paths, or with paths containing "exists".
+		 */
+		if ( 'd' === $type && ( '' === $path || str_contains( $path, 'exists' ) ) ) {
+			$expected = ! $expected;
+		}
+		$this->assertSame( $expected, self::$filesystem->is_file( self::$file_structure['test_dir']['path'] . $path ) );
+	}
+
+}