mirror of
https://github.com/NixOS/nixpkgs.git
synced 2024-12-22 23:10:02 +00:00
45 lines
1.2 KiB
Nix
45 lines
1.2 KiB
Nix
|
{ 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}";
|
||
|
|
|
||
|
|
}
|