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Use when adding transient fault handling around Result-based operations — ResiliencePolicy/ResiliencePolicy<T> for retry, timeout, circuit breaker, and fallback composition backed by Polly v8 with Result-aware retry filtering.
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SOC 職業分類に基づく
Use when representing optional values explicitly — Maybe<T> as a null-safe container, Maybe.From()/FromTry() for creation, HasValue/HasNoValue, Map/Bind chaining, TapNone for None-side effects, Match for consumption, and ToMaybeResult() to bridge into the Result pattern.
Use when handling operation outcomes without exceptions — Result and Result<T> for success/failure, railway-oriented chaining with Then/ThenAsync/Ensure, Match for consumption, and Result.And/Or for combining multiple results.
Use when composing business validation logic — define rules as classes, Func fields, or inline lambdas; combine with .And()/.Or()/.Linear()/.Next(); evaluate with RuleEngine.Evaluate(); branch with RuleEngine.If().
Use when modeling partial success — These<TError, TValue> holds Left (error only), Right (value only), or Both (error + value), enabling scenarios where a result can partially succeed while carrying warnings. Use FromResult to bridge from Result<T>, ToResult/ToResultLenient to bridge back, and Partition to split collections.
Use when you need testable time — IDateTimeProvider wraps clock access so production code uses DateTimeProvider while tests use the built-in FakeDateTimeProvider to freeze/advance/set the clock; also provides .ToDateOnly() and .ToTimeOnly() DateTime extension methods.
Use when adding cross-cutting pipeline behaviors to CQRS handlers — ValidationBehavior (CSharpEssentials.Validation, throws EnhancedValidationException), LoggingBehavior (ILoggableRequest), ExceptionHandlingBehavior (auto-converts exceptions to Result.Failure for Result-returning handlers), CachingBehavior (ICacheable with IDistributedCache), and TransactionScopeBehavior (ITransactionalRequest).
| name | csharpessentials-resilience |
| description | Use when adding transient fault handling around Result-based operations — ResiliencePolicy/ResiliencePolicy<T> for retry, timeout, circuit breaker, and fallback composition backed by Polly v8 with Result-aware retry filtering. |
HTTP-agnostic resilience patterns for Result and Result<T>. Compose retry, timeout, circuit breaker, and fallback without leaking Polly types into application code.
dotnet add package CSharpEssentials.Resilience
using CSharpEssentials.Resilience;
| Scenario | Use this package? |
|---|---|
| Transient fault handling (retry, timeout, circuit breaker) | ✅ Yes |
Composing resilience policies around Result<T> pipelines | ✅ Yes |
| Fallback values after retries are exhausted | ✅ Yes |
| HTTP-specific resilience (redirects, status code mapping) | ❌ No — use CSharpEssentials.Http |
| Non-Result exception-only retry logic | ⚠️ Consider Polly directly for simpler scenarios |
| Type | Description |
|---|---|
ResiliencePolicy | Non-generic policy for Result (unit) operations |
ResiliencePolicy<T> | Generic policy for Result<T> operations; supports fallback |
ResiliencePolicyOptions | Options record combining Retry, Timeout, CircuitBreaker |
RetryOptions | MaxAttempts, Delay, ExponentialBackoff |
TimeoutOptions | Timeout duration |
CircuitBreakerOptions | MinimumThroughput, SamplingDuration, BreakDuration, FailureRatio |
Result<User> user = await ResiliencePolicy
.Create()
.WithRetry(maxAttempts: 3, delay: TimeSpan.FromSeconds(1))
.WithTimeout(TimeSpan.FromSeconds(5))
.ExecuteAsync(ct => _db.GetUser(id, ct));
ResiliencePolicy<int> policy = ResiliencePolicy<int>.Create()
.WithRetry(maxAttempts: 3)
.WithCircuitBreaker(minimumThroughput: 10);
Result<int> result = await policy.ExecuteAsync(ct => _api.GetValue(ct));
// Direct execution — wraps any Func<Task<T>> in a Result
Result<User> user = await (() => _db.GetUser(id)).ExecuteAsync();
// RetryIfFailed — retries on transient Result failures
Func<CancellationToken, Task<Result<User>>> operation = ct => _db.GetUser(id, ct);
Result<User> retried = await operation.RetryIfFailed(maxAttempts: 3);
ResiliencePolicy<T> retries exceptions and failed Result<T> values, but skips these non-transient error types:
ErrorType.UnauthorizedErrorType.ForbiddenErrorType.NotFoundErrorType.ValidationConflict and unexpected failures are retried.
| Code | When |
|---|---|
Resilience.Timeout | Operation exceeded the configured timeout |
Resilience.CircuitBroken | Circuit breaker is open |
Timeout and circuit-breaker failures are returned as failed Result values rather than rethrown.
Fallback is available on ResiliencePolicy<T> and runs after prior strategies in the pipeline have been exhausted.
Result<Product> product = await ResiliencePolicy<Product>
.Create()
.WithRetry(maxAttempts: 3)
.WithFallback(ct => _cache.GetAsync<Product>(id, ct))
.ExecuteAsync(ct => _catalog.GetProduct(id, ct));
ResiliencePolicy<T> for operations that already return Result<T>; do not wrap Result<T> again.CancellationToken through the callback so Polly timeout and cancellation behave correctly.ResiliencePolicy from application and library code.CSharpEssentials.Resilience.