AssertionError and AssertionResult classes.
Assertion Error is a module that contains two classes: AssertionError, which
is an instance of an Error, and AssertionResult which is not an instance of
Error.
These can be useful for returning from a function - if the function "succeeds"
return an AssertionResult and if the function fails return (or throw) an
AssertionError.
Both AssertionError and AssertionResult implement the Result interface:
interface Result {
name: "AssertionError" | "AssertionResult";
ok: boolean;
toJSON(...args: unknown[]): Record<string, unknown>;
}So if a function returns AssertionResult | AssertionError it is easy to check
which one is returned by checking either .name or .ok, or check
instanceof Error.
assertion-error is available on npm.
$ npm install --save assertion-error
assertion_error is available on
Deno.land
import {
AssertionError,
AssertionResult,
} from "https://deno.land/x/[email protected]/mod.ts";