Fix/201 packagist api version

src/Package_Command.php

@@ -834,7 +834,7 @@
 		$options = [ 'insecure' => $insecure ];
 
 		// Check if the package exists on Packagist.
-		$url      = "https://repo.packagist.org/p/{$package_name}.json";
+		$url      = $this->get_packagist_url( $package_name, $options );
 		$response = Utils\http_request( 'GET', $url, null, [], $options );
 		if ( 20 === (int) substr( $response->status_code, 0, 2 ) ) {
 			return $package_name;
@@ -862,6 +862,20 @@
 		return false;
 	}
 
+	/**
+	 * Gets the correct packagist URL.
+	 */
+	private function get_packagist_url( $package_name, $options ) {
+		$url      = "https://repo.packagist.org/p2/{$package_name}.json";
+		$response = Utils\http_request( 'GET', $url, null, [], $options );
+
+		if ( 20 === (int) substr( $response->status_code, 0, 2 ) ) {
+			return $url;
+		}
+
+		return "https://repo.packagist.org/p/{$package_name}.json";
+	}
+
 	/**
 	 * Gets the installed community packages.
 	 */

tests/ComposerJsonTest.php

@@ -180,6 +180,25 @@
 		putenv( false === $env_wp_cli_packages_dir ? 'WP_CLI_PACKAGES_DIR' : "WP_CLI_PACKAGES_DIR=$env_wp_cli_packages_dir" );
 	}
 
+	public function test_get_packagist_url() {
+		$get_packagist_url = new \ReflectionMethod( 'Package_Command', 'get_packagist_url' );
+		$get_packagist_url->setAccessible( true );
+
+		$package = new Package_Command();
+		$options = [ 'insecure' => false ];
+
+		// Test with a valid package that should exist on packagist v1
+		$result = $get_packagist_url->invoke( $package, 'wp-cli/wp-cli', $options );
+		$this->assertStringContainsString( 'repo.packagist.org/p/', $result );
+		$this->assertStringContainsString( 'wp-cli/wp-cli.json', $result );
+
+		// The method should return either v1 or v2 URL based on availability
+		$this->assertTrue(
+			strpos( $result, 'https://repo.packagist.org/p/wp-cli/wp-cli.json' ) === 0 ||
+			strpos( $result, 'https://repo.packagist.org/p2/wp-cli/wp-cli.json' ) === 0
+		);
+	}
+
 	private function mac_safe_path( $path ) {
 		return preg_replace( '#^/private/(var|tmp)/#i', '/$1/', $path );
 	}