forked from denoland/std
-
Notifications
You must be signed in to change notification settings - Fork 0
/
assert_is_error.ts
43 lines (42 loc) · 1.45 KB
/
assert_is_error.ts
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
// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
import { AssertionError } from "./assertion_error.ts";
import { stripColor } from "../fmt/colors.ts";
/**
* Make an assertion that `error` is an `Error`.
* If not then an error will be thrown.
* An error class and a string that should be included in the
* error message can also be asserted.
*/
export function assertIsError<E extends Error = Error>(
error: unknown,
// deno-lint-ignore no-explicit-any
ErrorClass?: new (...args: any[]) => E,
msgIncludes?: string,
msg?: string,
): asserts error is E {
const msgSuffix = msg ? `: ${msg}` : ".";
if (error instanceof Error === false) {
throw new AssertionError(
`Expected "error" to be an Error object${msgSuffix}}`,
);
}
if (ErrorClass && !(error instanceof ErrorClass)) {
msg = `Expected error to be instance of "${ErrorClass.name}", but was "${
typeof error === "object" ? error?.constructor?.name : "[not an object]"
}"${msgSuffix}`;
throw new AssertionError(msg);
}
if (
msgIncludes && (!(error instanceof Error) ||
!stripColor(error.message).includes(stripColor(msgIncludes)))
) {
msg = `Expected error message to include ${
JSON.stringify(msgIncludes)
}, but got ${
error instanceof Error
? JSON.stringify(error.message)
: '"[not an Error]"' // TODO(kt3k): show more useful information
}${msgSuffix}`;
throw new AssertionError(msg);
}
}