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// This works by proxying every function call and wrapping a try-catch block to filter out redundant and confusing
// `RuntimeError: unreachable` exceptions that would normally be printed in the browser's JS console upon a panic.
export function panicProxy<T extends object>(module: T): T {
const proxyHandler = {
get(target: T, propKey: string | symbol, receiver: unknown): unknown {
const targetValue = Reflect.get(target, propKey, receiver);
// Keep the original value being accessed if it isn't a function
const isFunction = typeof targetValue === "function";
if (!isFunction) return targetValue;
// Special handling to wrap the return of a constructor in the proxy
const isClass = isFunction && /^\s*class\s+/.test(targetValue.toString());
if (isClass) {
// eslint-disable-next-line func-names
return function (...args: unknown[]): unknown {
// All three of these comment lines are necessary to suppress errors at both compile time and while editing this file (@ts-expect-error doesn't work here while editing the file)
// eslint-disable-next-line @typescript-eslint/ban-ts-comment
// @ts-ignore
// eslint-disable-next-line new-cap
const result = new targetValue(...args);
return panicProxy(result);
};
}
// Replace the original function with a wrapper function that runs the original in a try-catch block
// eslint-disable-next-line func-names
return function (...args: unknown[]): unknown {
let result;
try {
// @ts-expect-error TypeScript does not know what `this` is, since it should be able to be anything
result = targetValue.apply(this, args);
} catch (err) {
// Suppress `unreachable` WebAssembly.RuntimeError exceptions
if (!String(err).startsWith("RuntimeError: unreachable")) throw err;
}
return result;
};
},
};
return new Proxy<T>(module, proxyHandler);
}