Asyncify: Test all network functions and all ways to trigger a function call

[adamziel]

Description

As explained in #251 and #253, all PHP code paths leading to an asynchronous network call must be listed in php-wasm/compile/Dockerfile. In the longer term, we'll move from Asyncify to JSPI API that has a much simpler configuration, but for now we'll need to maintain the ASYNCIFY_ONLY list.

Finding them manually would be tedious or impossible, so #253 introduced a test suite that detects and auto-adds any missing code paths. That test suite should cover the following two concepts as exhaustively as possible:

Network functions

PHP functions directly responsible for triggering a network call like file_get_contents, fsockopen, mysql_connect should be listed here:

wordpress-playground/packages/php-wasm/node/src/test/php-asyncify.spec.ts

Lines 32 to 54 in 98a9d8d

	const topOfTheStack: Array<string> = [
	// http:// stream handler
	`file_get_contents(${js['httpUrl']});`,
	`$fp = fopen(${js['httpUrl']}, "r");
	fread($fp, 1024);
	fclose($fp);`,
	// `getimgsize(${js['httpUrl']});`,
	// Network functions from https://www.php.net/manual/en/book.network.php
	`$fp = fsockopen(${js['host']}, ${js['port']});
	fwrite($fp, "GET / HTTP/1.1\\r\\n\\r\\n");
	fread($fp, 10);
	fclose($fp);`,
	`gethostbyname(${js['httpUrl']});`,
	// @TODO:
	// https:// stream handler
	// MySQL functions from https://www.php.net/manual/en/book.mysql.php
	// PDO functions from https://www.php.net/manual/en/book.pdo.php
	// Sockets functions from https://www.php.net/manual/en/book.sockets.php
	];

A bunch of them already is, but there's also a TODO comment listing the missing ones

Function calls

Different ways of calling the network functions like a direct function call, method call, reflections API are covered by specific test cases here:

wordpress-playground/packages/php-wasm/node/src/test/php-asyncify.spec.ts

Lines 63 to 77 in 98a9d8d

	test('Direct call', () => assertNoCrash(` ${networkCall}`));
	describe('Function calls', () => {
	test('Simple call', () =>
	assertNoCrash(`function top() { ${networkCall} } top();`));
	test('Via call_user_func', () =>
	assertNoCrash(
	`function top() { ${networkCall} } call_user_func('top'); `
	));
	test('Via call_user_func_array', () =>
	assertNoCrash(
	`function top() { ${networkCall} } call_user_func_array('top', array());`
	));
	});
	describe('Class method calls', () => {

The initial list is nice, but we should also cover destructors, shutdown functions, serializable interface, and anything else you can think of.

Rebuilding PHP

After adding a test case, run

node --stack-trace-limit=100 ./node_modules/.bin/nx test php-wasm-node --test-name-pattern='asyncify'

If all the tests are green, good. If they're not, you may auto-fix the Dockerfile and rebuild PHP using this command:

npm run fix-asyncify

This takes some time so you may want to add all your test cases first and then run fix-asyncify just once at the end. Once it completes, all your new tests should pass.

[adamziel]

As identified in #387, the following code crashes PHP versions 5.6, 7.2, 8.2, and correctly throws an exception on all other versions:

<?php
class Top {
	function __clone() {
		file_get_contents("http://127.0.0.1");
	}
}
$x = new Top();
clone $x;