nf_fu_google_disconnect_trace.php

<?php

add_filter( 'pre_update_option_wp-oauth2-tokens', function ( $value, $old_value ) {
	if ( empty( $old_value['google'] ) ) {
		// Google not connected
		return $value;
	}
	if ( ! empty( $old_value['google'] ) && ! empty( $value['google'] ) ) {
		// Google still connected
		return $value;
	}
	// Dropbox was connected, not anymore - let's trace what called this update
	error_log( 'NF FU Google Disconnection' );
	error_log( print_r( pvw_generateCallTrace(), true ) );

	return $value;
}, 10, 2 );

function pvw_generateCallTrace() {
	$e     = new Exception();
	$trace = explode( "\n", $e->getTraceAsString() );
	// reverse array to make steps line up chronologically
	$trace = array_reverse( $trace );
	array_shift( $trace ); // remove {main}
	array_pop( $trace ); // remove call to this method
	$length = count( $trace );
	$result = array();
	for ( $i = 0; $i < $length; $i ++ ) {
		$result[] = ( $i + 1 ) . ')' . substr( $trace[ $i ], strpos( $trace[ $i ], ' ' ) ); // replace '#someNum' with '$i)', set the right ordering
	}

	return "\t" . implode( "\n\t", $result );
}