Class Expect

Namespace

Microsoft.Accordant

Assembly

Accordant.Operations.dll

Fluent API for defining expected outcomes in Operation.Apply methods. Provides a more readable way to construct ExpectedOutcome and ExpectedOutcomes.

public static class Expect

Inheritance

object

Expect

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Examples

// Simple case - predicate validation, state unchanged return Expect.That<int>(r => r == state.Value, "should equal current value");

// With state transition return Expect.That<int>(r => r == state.Value + 1, "should increment") .ThenState(state with { Value = state.Value + 1 });

// Response-dependent state (requires mock for exploration) return Expect.That<PutResponse>(r => r.ETag != null, "should have ETag") .ThenState( (resp, s) => s.WithETag(((PutResponse)resp).ETag), mock: () => new PutResponse { ETag = Guid.NewGuid().ToString() });

// With background activity return Expect.That<CopyResponse>(r => r.StatusCode == 202, "accepted") .ThenState(state.WithPendingCopy()) .Triggers((resp, s) => new CopyCompletionStepFunction(...));

// Multiple possible outcomes return Expect.OneOf( Expect.That<int>(r => r > 0, "positive").ThenState(positiveState), Expect.That<int>(r => r == 0, "zero").ThenState(zeroState));

Methods

OneOf(params ExpectedOutcome[])

Creates multiple expected outcomes (non-deterministic behavior). Use when an operation can have multiple valid outcomes.

public static ExpectedOutcomes OneOf(params ExpectedOutcome[] outcomes)

Parameters

outcomes ExpectedOutcome[]

The possible outcomes.

Returns

ExpectedOutcomes

An ExpectedOutcomes containing all possibilities.

OneOf<TResponse>(params ExpectedOutcomeBuilder<TResponse>[])

Creates multiple expected outcomes from builders (non-deterministic behavior). Use when an operation can have multiple valid outcomes.

public static ExpectedOutcomes OneOf<TResponse>(params ExpectedOutcomeBuilder<TResponse>[] builders)

Parameters

builders ExpectedOutcomeBuilder<TResponse>[]

The outcome builders.

Returns

ExpectedOutcomes

An ExpectedOutcomes containing all possibilities.

Type Parameters

TResponse

That(ResponseValidator)

Creates an expected outcome with a ResponseValidator.

public static ExpectedOutcomeBuilder<object> That(ResponseValidator validator)

Parameters

validator ResponseValidator

A ResponseValidator that validates responses.

Returns

ExpectedOutcomeBuilder<object>

An ExpectedOutcomeBuilder<TResponse> for further configuration.

That<TResponse>(ResponseValidator)

Creates a typed expected outcome with a ResponseValidator.

public static ExpectedOutcomeBuilder<TResponse> That<TResponse>(ResponseValidator validator)

Parameters

validator ResponseValidator

A ResponseValidator that validates responses.

Returns

ExpectedOutcomeBuilder<TResponse>

An ExpectedOutcomeBuilder<TResponse> for further configuration.

Type Parameters

TResponse

The type of response to validate.

That<TResponse>(Func<TResponse, ValidationResult>)

Creates an expected outcome with a ValidationResult-returning validator. This overload allows including the actual response value in error messages. Works well with FluentAssertions or FluentValidation libraries.

public static ExpectedOutcomeBuilder<TResponse> That<TResponse>(Func<TResponse, ValidationResult> validator)

Parameters

validator Func<TResponse, ValidationResult>

A function that validates the response and returns a ValidationResult containing both the validity and an explanation message.

Returns

ExpectedOutcomeBuilder<TResponse>

An ExpectedOutcomeBuilder<TResponse> for further configuration.

Type Parameters

TResponse

The type of response to validate.

Examples

// Rich error message with actual value Expect.That<int>(r => r > 0 ? ValidationResult.Valid() : ValidationResult.Invalid($"Expected positive but got {r}"))

That<TResponse>(Func<TResponse, bool>, string)

Creates an expected outcome with a predicate-based response validator.

public static ExpectedOutcomeBuilder<TResponse> That<TResponse>(Func<TResponse, bool> predicate, string explanation = null)

Parameters

predicate Func<TResponse, bool>

A predicate that returns true if the response is valid.

explanation string

A description of what the predicate checks (used in error messages).

Returns

ExpectedOutcomeBuilder<TResponse>

An ExpectedOutcomeBuilder<TResponse> for further configuration.

Type Parameters

TResponse

The type of response to validate.

Throws<TException>(Func<TException, bool>, string)

Creates an expected outcome for an operation that should throw an exception, with additional validation on the exception.

public static ExpectedOutcomeBuilder<Exception> Throws<TException>(Func<TException, bool> predicate, string explanation = null) where TException : Exception

Parameters

predicate Func<TException, bool>

Predicate to validate the exception.

explanation string

Optional explanation for error messages.

Returns

ExpectedOutcomeBuilder<Exception>

An ExpectedOutcomeBuilder<TResponse> for further configuration.

Type Parameters

TException

The expected exception type.

Examples

// Expect operation to throw with specific message return Expect.Throws<InsufficientFundsException>( ex => ex.Message.Contains("insufficient"), "should throw with 'insufficient' message") .SameState();

Throws<TException>(string)

Creates an expected outcome for an operation that should throw an exception. Use this when the operation is expected to throw rather than return normally.

public static ExpectedOutcomeBuilder<Exception> Throws<TException>(string explanation = null) where TException : Exception

Parameters

explanation string

Optional explanation for error messages.

Returns

ExpectedOutcomeBuilder<Exception>

An ExpectedOutcomeBuilder<TResponse> for further configuration.

Type Parameters

TException

The expected exception type.

Examples

// Expect operation to throw InsufficientFundsException return Expect.Throws<InsufficientFundsException>() .SameState();

Unit(string)

Creates an expected outcome for a void-returning operation. Use this when the operation returns Unit(string) (i.e., performs an action but returns no meaningful value).

public static ExpectedOutcomeBuilder<Unit> Unit(string explanation = null)

Parameters

explanation string

Optional explanation for error messages.

Returns

ExpectedOutcomeBuilder<Unit>

An ExpectedOutcomeBuilder<TResponse> for further configuration.

Examples

// Expect Push operation to succeed (returns Unit) return Expect.Unit() .ThenState(updatedState);