1 use std::{error, fmt};
2 
3 /// An enumeration of buffer creation errors
4 #[derive(Debug, Clone, Copy)]
5 #[non_exhaustive]
6 pub enum Error {
7     /// No choices were provided to the Unstructured::choose call
8     EmptyChoose,
9     /// There was not enough underlying data to fulfill some request for raw
10     /// bytes.
11     NotEnoughData,
12     /// The input bytes were not of the right format
13     IncorrectFormat,
14 }
15 
16 impl fmt::Display for Error {
fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result17     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
18         match self {
19             Error::EmptyChoose => write!(
20                 f,
21                 "`arbitrary::Unstructured::choose` must be given a non-empty set of choices"
22             ),
23             Error::NotEnoughData => write!(
24                 f,
25                 "There is not enough underlying raw data to construct an `Arbitrary` instance"
26             ),
27             Error::IncorrectFormat => write!(
28                 f,
29                 "The raw data is not of the correct format to construct this type"
30             ),
31         }
32     }
33 }
34 
35 impl error::Error for Error {}
36 
37 /// A `Result` with the error type fixed as `arbitrary::Error`.
38 ///
39 /// Either an `Ok(T)` or `Err(arbitrary::Error)`.
40 pub type Result<T, E = Error> = std::result::Result<T, E>;
41 
42 #[cfg(test)]
43 mod tests {
44     // Often people will import our custom `Result` type because 99.9% of
45     // results in a file will be `arbitrary::Result` but then have that one last
46     // 0.1% that want to have a custom error type. Don't make them prefix that
47     // 0.1% as `std::result::Result`; instead, let `arbitrary::Result` have an
48     // overridable error type.
49     #[test]
can_use_custom_error_types_with_result() -> super::Result<(), String>50     fn can_use_custom_error_types_with_result() -> super::Result<(), String> {
51         Ok(())
52     }
53 }
54