You can't try/catch a syntax error. You should never have a syntax error. But if you are writing a framework and suggesting that inexperienced users make minor modifications (power to the people!), it would be nice of you to provide a bit of a safety net. Here's how.

syntax_safe_include.php

<?php
function helper_syntax_safe_include ( $file, $reset = false ) {
	$key = sanitize_key( $file );

	if ( file_exists( $file) ) {
		// found it, no more hunting
	} elseif ( file_exists( trailingslashit( __DIR__ ) . ltrim( $file, '/' ) ) ) {
		$file = trailingslashit( __DIR__ ) . ltrim( $file, '/' );
	} elseif ( file_exists( trailingslashit( get_template_directory() ) . ltrim( $file, '/' ) ) ) {
		$file = trailingslashit( get_template_directory() ) . ltrim( $file, '/' );
	} else {
		return;
	}

	$last_update = filemtime( $file );
	$option = (array) get_option( 'helper_syntax_safe_include', array() );

	if ( ! isset( $option[$key][1] ) || $option[$key][1] < $last_update || $reset ) {
		$option[$key] = array( 'failed', $last_update );
		update_option( 'helper_syntax_safe_include', $option );
		header("Location: index.php");

		include_once( $file );

		header_remove('Location');
		$option[$key][0] = 'success';
		update_option( 'helper_syntax_safe_include', $option );
	} elseif ( 'success' == $option[$key][0] ) {
		include_once( $file );
	}
}

helper_syntax_safe_include('test-code.php');