Better handling for undefined constant

includes/Classifai/Command/RSSImporterCommand.php

@@ -200,8 +200,11 @@ public function get_url_meta( $url ) {
 			$options['headers'] = [];
 		}
 
-		$options['headers']['x-api-key'] = defined( MERCURY_PARSER_API_KEY ) ?? ''; /** @phpstan-ignore constant.notFound (If constant not defined, will use empty string instead) */
-		$options['timeout']              = 60; // phpcs:ignore WordPressVIPMinimum.Performance.RemoteRequestTimeout.timeout_timeout
+		if ( defined( \MERCURY_PARSER_API_KEY ) && \MERCURY_PARSER_API_KEY ) {
+			$options['headers']['x-api-key'] = \MERCURY_PARSER_API_KEY;
+		}
+
+		$options['timeout'] = 60; // phpcs:ignore WordPressVIPMinimum.Performance.RemoteRequestTimeout.timeout_timeout
 
 		$request_url = 'https://mercury.postlight.com/parser?url=' . rawurlencode( $url );
 		$response    = wp_remote_get( $request_url, $options ); // phpcs:ignore WordPressVIPMinimum.Functions.RestrictedFunctions.wp_remote_get_wp_remote_get

phpstan.neon.dist

@@ -12,13 +12,14 @@ parameters:
 	ignoreErrors:
 		# The JSDoc standard we use on hooks is not compatible with PHPStan.
 		- '#One or more @param tags has an invalid name or invalid syntax#'
-		- '#PHPDoc tag @(.+) has invalid value \({(.+)}(.*)\): Unexpected token "{"#'
+		# - '#PHPDoc tag @(.+) has invalid value \({(.+)}(.*)\): Unexpected token "{"#'
 		# Could look to fix this in the future.
 		- '#@param tag must not be named \$this. Choose a descriptive alias, for example \$instance#'
 		# Ignore ElasticPress for now, as we'll need to stub this.
 		- '#ElasticPress#'
 		# These constants are defined but we'd need to stub them for PHPStan to know.
 		- '#Constant CLASSIFAI_.+ not found#'
 		- '#Constant WATSON_.+ not found#'
+		- '#Constant MERCURY_PARSER_API_KEY not found#'
 	WPCompat:
 		requiresAtLeast: '6.1'