Enum DiError 

#[non_exhaustive]
pub enum DiError {
    NotFound(String),
    CircularDependency(String),
    ProviderError(String),
    TypeMismatch {
        expected: String,
        actual: String,
    },
    ScopeError(String),
    NotRegistered {
        type_name: String,
        hint: String,
    },
    DependencyNotRegistered {
        type_name: String,
    },
    Internal {
        message: String,
    },
    Authorization(String),
    Authentication(String),
    MissingParamContext {
        extractor: &'static str,
    },
    ParamExtraction(Box<ParamError>),
}

Errors that can occur during dependency injection resolution.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

NotFound(String)

The requested dependency was not found in the container.

CircularDependency(String)

A circular dependency chain was detected during resolution.

ProviderError(String)

An error occurred in a dependency provider function.

TypeMismatch

The resolved type did not match the expected type.

Fields

expected: String

The type that was expected.

actual: String

The type that was actually resolved.

ScopeError(String)

An error related to dependency scoping (request vs singleton).

NotRegistered

The requested type was not registered in the dependency registry.

Fields

type_name: String

The name of the unregistered type.

hint: String

A hint message suggesting how to register the type.

DependencyNotRegistered

A required dependency was not registered.

Fields

type_name: String

The name of the unregistered dependency type.

Internal

An internal error in the DI system.

Fields

message: String

A description of the internal error.

Authorization(String)

An authorization error (insufficient permissions).

Authentication(String)

An authentication error (user not authenticated).

MissingParamContext

An extractor requires HTTP request data, but the InjectionContext has no ParamContext attached.

Occurs when a factory or handler takes a request-scoped extractor (Path<T>, Query<T>, Json<T>, …) but the DI container was built without with_request(...).with_param_context(...). Typically a configuration bug — outside of tests, the request boundary should always populate both.

Fields

extractor: &'static str

Name of the extractor that triggered the failure ("Path", "Query", "Json", …) for diagnostic output.

ParamExtraction(Box<ParamError>)

A request-scoped extractor failed during HTTP parameter extraction.

Wraps the underlying params::ParamError so that callers can match on the inner variant (MissingParameter, ParseError, DeserializationError, Authentication, …) without duplicating the parameter-error taxonomy on DiError.

Implementations

impl DiError

pub fn from_param_error(err: ParamError) -> DiError

Convert a ParamError into a DiError, preserving authentication semantics.

From<ParamError> for DiError is deliberately not provided to avoid breaking type inference of the ? operator in Depends::resolve call sites generated by #[injectable_factory] — adding the impl introduces a second candidate From<E> for DiError and Rust’s inference engine fails to disambiguate (E0282). Call sites must therefore convert explicitly via .map_err(DiError::from_param_error).

Trait Implementations

impl Debug for DiError

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Display for DiError

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Error for DiError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<DiError> for Error

fn from(err: DiError) -> Error

Converts to this type from the input type.