diff options
Diffstat (limited to 'lib/asserts.nix')
| -rw-r--r-- | lib/asserts.nix | 22 |
1 files changed, 10 insertions, 12 deletions
diff --git a/lib/asserts.nix b/lib/asserts.nix index 8a5f1fb3feb76..9ae357cbc935e 100644 --- a/lib/asserts.nix +++ b/lib/asserts.nix @@ -2,35 +2,33 @@ rec { - /* Print a trace message if pred is false. + /* Throw if pred is false, else return pred. Intended to be used to augment asserts with helpful error messages. Example: assertMsg false "nope" - => false - stderr> trace: nope + stderr> error: nope - assert (assertMsg ("foo" == "bar") "foo is not bar, silly"); "" - stderr> trace: foo is not bar, silly - stderr> assert failed at … + assert assertMsg ("foo" == "bar") "foo is not bar, silly"; "" + stderr> error: foo is not bar, silly Type: assertMsg :: Bool -> String -> Bool */ # TODO(Profpatsch): add tests that check stderr assertMsg = pred: msg: - if pred - then true - else builtins.trace msg false; + pred || builtins.throw msg; /* Specialized `assertMsg` for checking if val is one of the elements of a list. Useful for checking enums. Example: - let sslLibrary = "libressl" + let sslLibrary = "libressl"; in assertOneOf "sslLibrary" sslLibrary [ "openssl" "bearssl" ] - => false - stderr> trace: sslLibrary must be one of "openssl", "bearssl", but is: "libressl" + stderr> error: sslLibrary must be one of [ + stderr> "openssl" + stderr> "bearssl" + stderr> ], but is: "libressl" Type: assertOneOf :: String -> ComparableVal -> List ComparableVal -> Bool |