Add panel for wp_mail() uses

collectors/emails.php

@@ -0,0 +1,202 @@
+<?php declare(strict_types = 1);
+/**
+ * Emails collector.
+ *
+ * @package query-monitor
+ */
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/**
+ * @extends QM_DataCollector<QM_Data_Emails>
+ */
+class QM_Collector_Emails extends QM_DataCollector {
+
+	public $id = 'emails';
+
+	public function get_storage(): QM_Data {
+		return new QM_Data_Emails();
+	}
+
+	/**
+	 * @return void
+	 */
+	public function set_up() {
+		parent::set_up();
+		add_filter( 'wp_mail', array( $this, 'filter_wp_mail' ), 9999 );
+		add_filter( 'pre_wp_mail', array( $this, 'filter_pre_wp_mail' ), 9999, 2 );
+		add_action( 'wp_mail_failed', array( $this, 'action_wp_mail_failed' ) );
+	}
+
+	/**
+	 * @return void
+	 */
+	public function tear_down() {
+		remove_filter( 'wp_mail', array( $this, 'filter_wp_mail' ), 9999 );
+		remove_filter( 'pre_wp_mail', array( $this, 'filter_pre_wp_mail' ), 9999 );
+		remove_action( 'wp_mail_failed', array( $this, 'action_wp_mail_failed' ) );
+
+		parent::tear_down();
+	}
+
+	/**
+	 * @return array<int, string>
+	 */
+	public function get_concerned_actions() {
+		return array(
+			'phpmailer_init',
+			'wp_mail_succeeded',
+			'wp_mail_failed',
+		);
+	}
+
+	/**
+	 * @return array<int, string>
+	 */
+	public function get_concerned_filters() {
+		return array(
+			'pre_wp_mail',
+			'wp_mail',
+			'wp_mail_from',
+			'wp_mail_from_name',
+			'wp_mail_content_type',
+			'wp_mail_charset',
+		);
+	}
+
+	/**
+	 * Other attributes of wp_mail() are changed,
+	 * so use the attributes that aren't changed
+	 * to generate identifying hash.
+	 *
+	 * @param array<string, string|array<int, string>> $atts
+	 * @return string
+	 */
+	protected function hash( $atts ) {
+		$to = $atts['to'];
+
+		if ( ! is_array( $to ) ) {
+			$to = explode( ',', $to );
+			$to = array_map( 'trim', $to );
+		}
+
+		$data = array(
+			'to'      => $to,
+			'subject' => $atts['subject'],
+			'message' => $atts['message'],
+		);
+
+		$datastring = json_encode( $data );
+
+		if ( ! is_string( $datastring ) ) {
+			$datastring = print_r( $data, true );
+		}
+
+		return wp_hash( $datastring );
+	}
+
+	/**
+	 * @param array<string, string|array<int, string>> $atts
+	 * @return array<string, string|array<int, string>>
+	 */
+	public function filter_wp_mail( $atts ) {
+		$atts = wp_parse_args( $atts, array(
+			'to'          => array(),
+			'subject'     => '',
+			'message'     => '',
+			'headers'     => array(),
+			'attachments' => array(),
+		) );
+
+		if ( ! is_array( $atts['to'] ) ) {
+			$atts['to'] = explode( ',', $atts['to'] );
+		}
+
+		if ( ! is_array( $atts['attachments'] ) ) {
+			$atts['attachments'] = explode( "\n", str_replace( "\r\n", "\n", $atts['attachments'] ) );
+		}
+
+		$hash  = $this->hash( $atts );
+		$trace = new QM_Backtrace( array(
+			'ignore_hook' => array(
+				current_filter() => true,
+			),
+		) );
+
+		$this->data->emails[ $hash ] = array(
+			'atts'           => $atts,
+			'error'          => null,
+			'filtered_trace' => $trace->get_filtered_trace(),
+		);
+
+		return $atts;
+	}
+
+	/**
+	 * @param null|bool $preempt
+	 * @param array<string, string|array<int, string>> $atts
+	 * @return null|bool
+	 */
+	public function filter_pre_wp_mail( $preempt, $atts ) {
+		if ( is_null( $preempt ) ) {
+			return null;
+		}
+
+		$hash = $this->hash( $atts );
+
+		$this->data->preempted[] = $hash;
+		$this->data->emails[ $hash ]['error'] = new WP_Error( 'pre_wp_mail', 'Preempted sending email.' );
+
+		return $preempt;
+	}
+
+	/**
+	 * @param WP_Error $error
+	 * @return void
+	 */
+	public function action_wp_mail_failed( $error ) {
+		$atts  = $error->get_error_data( 'wp_mail_failed' );
+		$hash  = $this->hash( $atts );
+
+		$this->data->failed[]        = $hash;
+		$this->data->emails[ $hash ]['error'] = $error;
+	}
+
+	/**
+	 * @return void
+	 */
+	public function process() {
+		$this->data->counts = array(
+			'preempted' => 0,
+			'failed'    => 0,
+			'succeeded' => 0,
+			'total'     => 0,
+		);
+
+		if ( ! is_array( $this->data->preempted ) ) {
+			$this->data->preempted = array();
+		}
+
+		if ( ! is_array( $this->data->failed ) ) {
+			$this->data->failed = array();
+		}
+
+		foreach ( $this->data->emails as $hash => $email ) {
+			$this->data->counts['total']++;
+
+			if ( in_array( $hash, $this->data->preempted ) ) {
+				$this->data->counts['preempted']++;
+			} else if ( in_array( $hash, $this->data->failed ) ) {
+				$this->data->counts['failed']++;
+			} else {
+				$this->data->counts['succeeded']++;
+			}
+		}
+	}
+
+}
+
+# Load early to catch early emails
+QM_Collectors::add( new QM_Collector_Emails() );

data/emails.php

@@ -0,0 +1,28 @@
+<?php declare(strict_types = 1);
+/**
+ * Emails data transfer object.
+ *
+ * @package query-monitor
+ */
+
+class QM_Data_Emails extends QM_Data {
+	/**
+	 * @var array<string, array<string, mixed>>
+	 */
+	public $emails;
+
+	/**
+	 * @var array<int, string>
+	 */
+	public $preempted;
+
+	/**
+	 * @var array<int, string>
+	 */
+	public $failed;
+
+	/**
+	 * @var array<string, int>
+	 */
+	public $counts;
+}