Failure class

Represents a failure in an operation, usually as the Left value of an Either.

Contains a human-readable error message, optional machine-readable code, and optional structured details.

Annotations

• @immutable

Constructors

Failure([String message = 'An unexpected error occurred.', String? code, Map<String, dynamic> details = const {}])

Creates a Failure with an optional message. Defaults to a generic error message.

const

Failure.fromError(Object error, [StackTrace? stackTrace])

Wraps a caught error as a Failure.

factory

Properties

code → String?

An optional stable code for programmatic error handling.

final

details → Map<String, dynamic>

Optional structured metadata describing the failure.

final

hashCode → int

The hash code for this object.

no setter, override

message → String

The error message describing the failure.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

copyWith({String? message, String? code, Map<String, dynamic>? details}) → Failure

Returns a copy with the given fields replaced.

detail<T>(String key) → T?

Reads a details entry as T, or null when absent or mistyped.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

override

withDetail(String key, Object? value) → Failure

Returns a copy with one extra entry in details.

withDetails(Map<String, dynamic> extra) → Failure

Returns a copy with extra merged into details.

Operators

operator ==(Object other) → bool

The equality operator.

override