Commit Graph

4 Commits

Author SHA1 Message Date
David Tolnay
d1d8fb939a Switch from failure::Fail trait to std::error::Error for errors
Summary:
This diff replaces eden's dependencies on failure::Error with anyhow::Error.

Failure's error type requires all errors to have an implementation of failure's own failure::Fail trait in order for cause chains and backtraces to work. The necessary methods for this functionality have made their way into the standard library error trait, so modern error libraries build directly on std::error::Error rather than something like failure::Fail. Once we are no longer tied to failure 0.1's Fail trait, different parts of the codebase will be free to use any std::error::Error-based libraries they like while still working nicely together.

Reviewed By: xavierd

Differential Revision: D18576093

fbshipit-source-id: e2d862b659450f2969520d9b74877913fabb2e5d
2019-11-22 08:53:31 -08:00
David Tolnay
9c6f253858 rust: Replace derive(Fail) with derive(Error)
Summary:
This diff replaces code of the form:

```
use failure::Fail;

#[derive(Fail, Debug)]
pub enum ErrorKind {
    #[fail(display = "something failed {} times", _0)]
    Failed(usize),
}
```

with:

```
use thiserror::Error;

#[derive(Error, Debug)]
pub enum ErrorKind {
    #[error("something failed {0} times")]
    Failed(usize),
}
```

The former emits an implementation of failure 0.1's `Fail` trait while the latter emits an impl of `std::error::Error`. Failure provides a blanket impl of `Fail` for any type that implements `Error`, so these `Error` impls are strictly more general. Each of these error types will continue to have exactly the same `Fail` impl that it did before this change, but now also has the appropriate `std::error::Error` impl which sets us up for dropping our various dependencies on `Fail` throughout the codebase.

Reviewed By: Imxset21

Differential Revision: D18523700

fbshipit-source-id: 0e43b10d5dfa79820663212391ecbf4aeaac2d41
2019-11-14 22:04:38 -08:00
David Tolnay
b1793a4416 rust: Rename Fallible<T> to Result<T>
Summary:
This diff is preparation for migrating off of failure::Fail / failure::Error for errors in favor of errors that implement std::error::Error. The Fallible terminology is unique to failure and in non-failure code we should be using Result<T>. To minimize the size of the eventual diff that removes failure, this codemod replaces all use of Fallible with Result by:

- In modules that do not use Result<T, E>, we import `failure::Fallible as Result`;
- In modules that use a mix of Result<T, E> and Fallible<T> (only 5) we define `type Result<T, E = failure::Error> = std::result::Result<T, E>` to allow both Result<T> and Result<T, E> to work simultaneously.

Reviewed By: Imxset21

Differential Revision: D18499758

fbshipit-source-id: 9f5a54c47f81fdeedbc6003cef42a1194eee55bf
2019-11-14 14:11:01 -08:00
Adam Simpkins
ab3a7cb21f Move fb-mercurial sources into an eden/scm subdirectory.
Summary:
In preparation for merging fb-mercurial sources to the Eden repository,
move everything from the top-level directory into an `eden/scm`
subdirectory.
2019-11-13 16:04:48 -08:00