@awayfl/avm2/lib/run/axAdd.ts

Virtual machine for executing AS3 code

import { AXSecurityDomain } from './AXSecurityDomain';
import { release } from '@awayfl/swf-loader';
import { assert } from '@awayjs/graphics';
import { isXMLCollection, ASXMLList } from '../natives/xml';

/**
 * ActionScript 3 has different behaviour when deciding whether to call toString or valueOf
 * when one operand is a string. Unlike JavaScript, it calls toString if one operand is a
 * string and valueOf otherwise. This sucks, but we have to emulate this behaviour because
 * YouTube depends on it.
 *
 * AS3 also overloads the `+` operator to concatenate XMLs/XMLLists instead of stringifying them.
 */
export function axAdd(l: any, r: any, sec: AXSecurityDomain): any {
	release || assert(!(typeof l === 'number' && typeof r === 'number'), 'Inline number addition.');
	if (typeof l === 'string' || typeof r === 'string') {
		return String(l) + String(r);
	}
	if (isXMLCollection(sec, l) && isXMLCollection(sec, r)) {
		return ASXMLList.addXML(l, r);
	}
	return l + r;
}