Source

File: wp-includes/link-template.php

function get_edit_post_link( $id = 0, $context = 'display' ) {
	$post = get_post( $id );
	if ( ! $post ) {
		return;
	}

	if ( 'revision' === $post->post_type ) {
		$action = '';
	} elseif ( 'display' === $context ) {
		$action = '&action=edit';
	} else {
		$action = '&action=edit';
	}

	$post_type_object = get_post_type_object( $post->post_type );
	if ( ! $post_type_object ) {
		return;
	}

	if ( ! current_user_can( 'edit_post', $post->ID ) ) {
		return;
	}

	if ( $post_type_object->_edit_link ) {
		$link = admin_url( sprintf( $post_type_object->_edit_link . $action, $post->ID ) );
	} else {
		$link = '';
	}

	/**
	 * Filters the post edit link.
	 *
	 * @since 2.3.0
	 *
	 * @param string $link    The edit link.
	 * @param int    $post_id Post ID.
	 * @param string $context The link context. If set to 'display' then ampersands
	 *                        are encoded.
	 */
	return apply_filters( 'get_edit_post_link', $link, $post->ID, $context );
}