Crate edgedb_errors
source ·Expand description
§Error Handling for EdgeDB
All errors that EdgeDB Rust bindings produce are encapsulated into the
Error
structure. The structure is a bit like Box<dyn Error>
or
anyhow::Error
, except it can only contain EdgeDB error types. Or
UserError
can be used to encapsulate custom errors (commonly used
to return an error from a transaction).
A full list of EdgeDB error types on a single page can be found on the website documentation.
Each error kind is represented as a separate type that implements the
ErrorKind
trait. But error kinds are used like marker structs; you can
use Error::is
for error kinds and use them to create instances of the
error:
let err = UserError::with_source(io::Error::from(io::ErrorKind::NotFound));
assert!(err.is::<UserError>());
Since errors are hirarchical, Error::is
works with any ancestor:
assert!(err.is::<MissingArgumentError>());
assert!(err.is::<QueryArgumentError>()); // implied by the assertion above
assert!(err.is::<InterfaceError>()); // and this one
assert!(err.is::<ClientError>()); // and this one
Error hierarchy doesn’t have multiple inheritance (i.e. every error has only single parent). When we match across different parents we use error tags:
assert!(err1.is::<ClientConnectionTimeoutError>());
assert!(err2.is::<TransactionConflictError>());
// Both of these are retried
assert!(err1.has_tag(SHOULD_RETRY));
assert!(err2.has_tag(SHOULD_RETRY));
// But they aren't a part of common hierarchy
assert!(err1.is::<ClientError>());
assert!(!err1.is::<ExecutionError>());
assert!(err2.is::<ExecutionError>());
assert!(!err2.is::<ClientError>());
§Errors in Transactions
Special care for errors must be taken in transactions. Generally:
- Errors from queries should not be ignored, and should be propagagated up to the transaction function.
- User errors can be encapsulated into
UserError
via one of the methods:ErrorKind::with_source
(for anystd::error::Error
)ErrorKind::with_source_box
already boxed errorErrorKind::with_source_ref
for smart wrappers such asanyhow::Error
- Original query error must be propagated via error chain. It can be in the
.source()
chain but must not be swallowed, otherwise retrying transaction may work incorrectly.
§Nice Error Reporting
Refer to documentation in the edgedb-tokio crate.
Re-exports§
pub use kinds::*;
Modules§
- All errors from the EdgeDB protocol
Structs§
- Error type returned from any EdgeDB call.
- Tag that is used to group similar errors.
Traits§
- Trait that marks EdgeDB errors.