blob: 8a5f1fb3feb76a200ba2c9c016ab50d7e6e1a0c4 (
plain) (
blame)
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
|
{ lib }:
rec {
/* Print a trace message if pred is false.
Intended to be used to augment asserts with helpful error messages.
Example:
assertMsg false "nope"
=> false
stderr> trace: nope
assert (assertMsg ("foo" == "bar") "foo is not bar, silly"); ""
stderr> trace: foo is not bar, silly
stderr> assert failed at …
Type:
assertMsg :: Bool -> String -> Bool
*/
# TODO(Profpatsch): add tests that check stderr
assertMsg = pred: msg:
if pred
then true
else builtins.trace msg false;
/* Specialized `assertMsg` for checking if val is one of the elements
of a list. Useful for checking enums.
Example:
let sslLibrary = "libressl"
in assertOneOf "sslLibrary" sslLibrary [ "openssl" "bearssl" ]
=> false
stderr> trace: sslLibrary must be one of "openssl", "bearssl", but is: "libressl"
Type:
assertOneOf :: String -> ComparableVal -> List ComparableVal -> Bool
*/
assertOneOf = name: val: xs: assertMsg
(lib.elem val xs)
"${name} must be one of ${
lib.generators.toPretty {} xs}, but is: ${
lib.generators.toPretty {} val}";
}
|
