Class ScenarioBuilder<T>

Provides a fluent arrange/act/assert pipeline for a tracked scenario target.

Inheritance
object
ScenarioBuilder<T>
Inherited Members
Namespace: FastMoq
Assembly: FastMoq.Core.dll
Syntax
public sealed class ScenarioBuilder<T> where T : class
Type Parameters
Name Description
T
Examples

In MockerTestBase<TComponent>, prefer the parameterless overloads when Component is already available.

This example uses the scenario pipeline together with provider-first verification.

Scenario
    .When(() => Component.Submit(42))
    .Then(() => Component.Channel.Should().Be("priority"))
    .Verify<IOrderGateway>(x => x.Publish(42), TimesSpec.Once)
    .VerifyNoOtherCalls<IOrderGateway>()
    .Execute();

Outside MockerTestBase<TComponent>, use the target-instance overloads.

await mocker.Scenario(service)
    .When(component => component.RunAsync())
    .Verify<IBackgroundQueue>(x => x.Enqueue("job-42"), TimesSpec.Once)
    .ExecuteAsync();

Properties

Instance

Gets the current scenario target instance.

Declaration
public T Instance { get; }
Property Value
Type Description
T

Methods

Execute()

Convenience execute for synchronous test bodies.

Declaration
public void Execute()

ExecuteAsync()

Executes the scenario (arrange -> act -> assert).

Declaration
public Task ExecuteAsync()
Returns
Type Description
Task

ExecuteThrowsAsync<TException>()

Executes the scenario and returns the expected exception.

Declaration
public Task<TException> ExecuteThrowsAsync<TException>() where TException : Exception
Returns
Type Description
Task<TException>
Type Parameters
Name Description
TException
Examples
var exception = await mocker.Scenario(service)
    .When(component => component.RunAsync())
    .ExecuteThrowsAsync<InvalidOperationException>();

ExecuteThrows<TException>()

Executes the scenario and returns the expected exception.

Declaration
public TException ExecuteThrows<TException>() where TException : Exception
Returns
Type Description
TException
Type Parameters
Name Description
TException
Examples

Use this form when the exception object itself is the primary assertion target.

var exception = Scenario
    .When(() => Component.SendRemindersAsync(now, CancellationToken.None))
    .ExecuteThrows<InvalidOperationException>();

exception.Message.Should().Be("SMTP unavailable");

Then(Action)

Adds an assertion step.

Declaration
public ScenarioBuilder<T> Then(Action assertion)
Parameters
Type Name Description
Action assertion
Returns
Type Description
ScenarioBuilder<T>

Then(Action<Mocker, T>)

Adds an assertion step.

Declaration
public ScenarioBuilder<T> Then(Action<Mocker, T> assertion)
Parameters
Type Name Description
Action<Mocker, T> assertion
Returns
Type Description
ScenarioBuilder<T>

Then(Action<T>)

Adds a synchronous assertion step using only the component instance.

Declaration
public ScenarioBuilder<T> Then(Action<T> assertion)
Parameters
Type Name Description
Action<T> assertion
Returns
Type Description
ScenarioBuilder<T>

Then(Func<Mocker, T, Task>)

Adds an asynchronous assertion step.

Declaration
public ScenarioBuilder<T> Then(Func<Mocker, T, Task> assertion)
Parameters
Type Name Description
Func<Mocker, T, Task> assertion
Returns
Type Description
ScenarioBuilder<T>

Then(Func<Task>)

Adds an asynchronous assertion step.

Declaration
public ScenarioBuilder<T> Then(Func<Task> assertion)
Parameters
Type Name Description
Func<Task> assertion
Returns
Type Description
ScenarioBuilder<T>

Then(Func<T, Task>)

Adds an asynchronous assertion step using only the component instance.

Declaration
public ScenarioBuilder<T> Then(Func<T, Task> assertion)
Parameters
Type Name Description
Func<T, Task> assertion
Returns
Type Description
ScenarioBuilder<T>

VerifyNoOtherCalls<TMock>()

Queues a provider-first VerifyNoOtherCalls step to run during scenario execution.

Declaration
public ScenarioBuilder<T> VerifyNoOtherCalls<TMock>() where TMock : class
Returns
Type Description
ScenarioBuilder<T>
Type Parameters
Name Description
TMock

Verify<TMock>(Expression<Action<TMock>>, TimesSpec?)

Queues a provider-first verification step to run during scenario execution.

Declaration
public ScenarioBuilder<T> Verify<TMock>(Expression<Action<TMock>> expression, TimesSpec? times = null) where TMock : class
Parameters
Type Name Description
Expression<Action<TMock>> expression
TimesSpec? times
Returns
Type Description
ScenarioBuilder<T>
Type Parameters
Name Description
TMock

When(Action)

Adds a synchronous act step.

Declaration
public ScenarioBuilder<T> When(Action act)
Parameters
Type Name Description
Action act
Returns
Type Description
ScenarioBuilder<T>

When(Action<Mocker, T>)

Adds a synchronous act step.

Declaration
public ScenarioBuilder<T> When(Action<Mocker, T> act)
Parameters
Type Name Description
Action<Mocker, T> act
Returns
Type Description
ScenarioBuilder<T>

When(Action<T>)

Adds a synchronous act step using only the component instance.

Declaration
public ScenarioBuilder<T> When(Action<T> act)
Parameters
Type Name Description
Action<T> act
Returns
Type Description
ScenarioBuilder<T>

When(Func<Mocker, T, Task>)

Adds an asynchronous act step.

Declaration
public ScenarioBuilder<T> When(Func<Mocker, T, Task> act)
Parameters
Type Name Description
Func<Mocker, T, Task> act
Returns
Type Description
ScenarioBuilder<T>

When(Func<Task>)

Adds an asynchronous act step.

Declaration
public ScenarioBuilder<T> When(Func<Task> act)
Parameters
Type Name Description
Func<Task> act
Returns
Type Description
ScenarioBuilder<T>

When(Func<T, Task>)

Adds an asynchronous act step using only the component instance.

Declaration
public ScenarioBuilder<T> When(Func<T, Task> act)
Parameters
Type Name Description
Func<T, Task> act
Returns
Type Description
ScenarioBuilder<T>

WhenThrows<TException>(Action)

Adds a synchronous act step that is expected to throw the specified exception type.

Declaration
public ScenarioBuilder<T> WhenThrows<TException>(Action act) where TException : Exception
Parameters
Type Name Description
Action act
Returns
Type Description
ScenarioBuilder<T>
Type Parameters
Name Description
TException
Examples

Use this when the act step is expected to fail but trailing assertions should still run.

Scenario
    .WhenThrows<InvalidOperationException>(() => Component.SendRemindersAsync(now, CancellationToken.None))
    .Then(() => auditTrail.Count.Should().Be(1))
    .Execute();

WhenThrows<TException>(Action<Mocker, T>)

Adds a synchronous act step using the mocker and component instance that is expected to throw the specified exception type.

Declaration
public ScenarioBuilder<T> WhenThrows<TException>(Action<Mocker, T> act) where TException : Exception
Parameters
Type Name Description
Action<Mocker, T> act
Returns
Type Description
ScenarioBuilder<T>
Type Parameters
Name Description
TException

WhenThrows<TException>(Action<T>)

Adds a synchronous act step using only the component instance that is expected to throw the specified exception type.

Declaration
public ScenarioBuilder<T> WhenThrows<TException>(Action<T> act) where TException : Exception
Parameters
Type Name Description
Action<T> act
Returns
Type Description
ScenarioBuilder<T>
Type Parameters
Name Description
TException

WhenThrows<TException>(Func<Mocker, T, Task>)

Adds an asynchronous act step using the mocker and component instance that is expected to throw the specified exception type.

Declaration
public ScenarioBuilder<T> WhenThrows<TException>(Func<Mocker, T, Task> act) where TException : Exception
Parameters
Type Name Description
Func<Mocker, T, Task> act
Returns
Type Description
ScenarioBuilder<T>
Type Parameters
Name Description
TException

WhenThrows<TException>(Func<Task>)

Adds an asynchronous act step that is expected to throw the specified exception type.

Declaration
public ScenarioBuilder<T> WhenThrows<TException>(Func<Task> act) where TException : Exception
Parameters
Type Name Description
Func<Task> act
Returns
Type Description
ScenarioBuilder<T>
Type Parameters
Name Description
TException
Examples
await mocker.Scenario(service)
    .WhenThrows<InvalidOperationException>(component => component.RunAsync())
    .Then(component => component.Attempts.Should().Be(1))
    .ExecuteAsync();

WhenThrows<TException>(Func<T, Task>)

Adds an asynchronous act step using only the component instance that is expected to throw the specified exception type.

Declaration
public ScenarioBuilder<T> WhenThrows<TException>(Func<T, Task> act) where TException : Exception
Parameters
Type Name Description
Func<T, Task> act
Returns
Type Description
ScenarioBuilder<T>
Type Parameters
Name Description
TException

With(Action)

Adds an arrangement action executed before any When/Act operations.

Declaration
public ScenarioBuilder<T> With(Action arrange)
Parameters
Type Name Description
Action arrange
Returns
Type Description
ScenarioBuilder<T>

With(Action<Mocker, T>)

Adds an arrangement action executed before any When/Act operations.

Declaration
public ScenarioBuilder<T> With(Action<Mocker, T> arrange)
Parameters
Type Name Description
Action<Mocker, T> arrange
Returns
Type Description
ScenarioBuilder<T>

With(Action<T>)

Adds an arrangement action using only the component instance.

Declaration
public ScenarioBuilder<T> With(Action<T> arrange)
Parameters
Type Name Description
Action<T> arrange
Returns
Type Description
ScenarioBuilder<T>

With(Func<Mocker, T, Task>)

Adds an asynchronous arrangement action executed before any When/Act operations.

Declaration
public ScenarioBuilder<T> With(Func<Mocker, T, Task> arrange)
Parameters
Type Name Description
Func<Mocker, T, Task> arrange
Returns
Type Description
ScenarioBuilder<T>

With(Func<Task>)

Adds an asynchronous arrangement action executed before any When/Act operations.

Declaration
public ScenarioBuilder<T> With(Func<Task> arrange)
Parameters
Type Name Description
Func<Task> arrange
Returns
Type Description
ScenarioBuilder<T>

With(Func<T, Task>)

Adds an asynchronous arrangement action using only the component instance.

Declaration
public ScenarioBuilder<T> With(Func<T, Task> arrange)
Parameters
Type Name Description
Func<T, Task> arrange
Returns
Type Description
ScenarioBuilder<T>

With(T)

Replaces the scenario target instance. This enables fluent patterns such as Scenario.With(Component).

Declaration
public ScenarioBuilder<T> With(T instance)
Parameters
Type Name Description
T instance
Returns
Type Description
ScenarioBuilder<T>

Extension Methods