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488d96b | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 | /**
* Structural not-implemented stubs: a replaced module must expose every symbol
* its importers name (a missing CommonJS symbol degrades to `undefined` at call
* time instead of failing at link time), and every one of those symbols must
* report exactly what is unavailable when it is finally called.
*/
/**
* Build a function that throws naming its module and symbol. The refusal is
* also written to the console before it propagates: callers routinely swallow
* these errors far from their cause, and the console line is what places the
* failure while debugging a worker session.
*
* `Face` is the Node declaration this stub stands in for, so the replaced module
* publishes the type its importers compile against. The value is one throwing
* function whatever that declaration says: a caller reaches the throw before any
* declared parameter, return value, or `new` result exists, so the assertion
* below cannot be observed as a lie. It is a function expression rather than an
* arrow because a stub standing in for a class must refuse under `new` too, and
* an arrow has no construct behavior to reach.
* @param module - module specifier being stubbed.
* @param symbol - exported symbol name.
* @returns the throwing stand-in, typed as the member it replaces.
*/
// eslint-disable-next-line @typescript-eslint/no-unnecessary-type-parameters -- only the return position carries the Node declaration
export function notImplementedFail<Face = (...args: never[]) => never>(module: string, symbol: string): Face {
return (function refuse(): never {
throw notAvailableError(module, symbol)
}) as Face
}
/**
* Build the refusal error and write it to the console first, for stubs that
* cannot be a plain throwing function (constructors, methods on structural
* fakes).
* @param module - module specifier being stubbed.
* @param symbol - unavailable member, named as the importer sees it.
* @returns the error to throw.
*/
export function notAvailableError(module: string, symbol: string): Error {
const message = `web-preview: ${module}.${symbol} is not available in the worker host`
console.error(message)
return new Error(message)
}
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