FluentSeq provides a fluent interface for creating easy-to-read sequences,
eliminating the need for lengthy if/else statements.
The library is written in C# 14 and targets .NET Standard 2.0 (.NET (Core) and .NET Framework).
FluentSeq is the successor of IegTools.Sequencer
The library allows you to configure:
- Sequences with States
- different kinds of State-Triggers
- Actions that can be executed on State-Entry, State-Exit or WhileInState
- Validate a sequence on build to avoid misconfigurations (missing states, triggers, etc.)
Installation
Usage
States
Trigger
Actions
Validation
Version Changes
Breaking Changes
Preview next Version v2.0
The library is available as a NuGet package.
A simple example configuration and usage for an OnTimer-sequence as xUnit-Test:
using FluentSeq.Builder;
using FluentSeq.Core;
public class OnTimerCreateExampleTests
{
private ISequence<TimerState>? _sequence;
private bool _onTimerInput;
private ISequenceBuilder<TimerState> GetOnTimerConfiguration(int dwellTimeInMs) =>
new FluentSeq<TimerState>().Create(TimerState.Off)
.ConfigureState(TimerState.Off)
.TriggeredBy(() => !_onTimerInput)
.ConfigureState(TimerState.Pending)
.TriggeredBy(() => _onTimerInput)
.WhenInState(TimerState.Off)
.ConfigureState(TimerState.On)
.TriggeredBy(() => _onTimerInput)
.WhenInState(TimerState.Pending, () => TimeSpan.FromMilliseconds(dwellTimeInMs))
.Builder();
[Theory]
[InlineData(false, 9, 0, TimerState.Off, TimerState.Off)]
[InlineData(false, 9, 0, TimerState.Pending, TimerState.Off)]
[InlineData(false, 9, 0, TimerState.On, TimerState.Off)]
[InlineData(false, 1, 2, TimerState.Off, TimerState.Off)]
[InlineData(false, 1, 2, TimerState.Pending, TimerState.Off)]
[InlineData(false, 1, 2, TimerState.On, TimerState.Off)]
[InlineData(true, 9, 0, TimerState.Off, TimerState.Pending)]
[InlineData(true, 9, 0, TimerState.Pending, TimerState.Pending)]
[InlineData(true, 9, 0, TimerState.On, TimerState.On)]
[InlineData(true, 1, 2, TimerState.Off, TimerState.Pending)]
[InlineData(true, 1, 2, TimerState.Pending, TimerState.On)]
[InlineData(true, 1, 2, TimerState.On, TimerState.On)]
public async Task Example_Usage_OnTimerConfiguration_Run_async(bool timerInput, int dwellTimeInMs, int sleepTimeInMs, TimerState currentState, TimerState expectedState)
{
_sequence = GetOnTimerConfiguration(dwellTimeInMs).Build();
_onTimerInput = timerInput;
_sequence.SetState(currentState);
await Task.Delay(sleepTimeInMs);
await _sequence.RunAsync();
var actual = _sequence.CurrentState;
actual.ShouldBe(expectedState);
}
}A simple example configuration and usage for an OffTimer-sequence as xUnit-Test:
using FluentSeq.Builder;
using FluentSeq.Core;
public class OffTimerConfigureExampleTests
{
private ISequence<TimerState>? _sequence;
private bool _onTimerInput;
private ISequenceBuilder<TimerState> GetOffTimerConfiguration(int dwellTimeInMs) =>
new FluentSeq<TimerState>().Configure(TimerState.Off, builder =>
{
builder.ConfigureState(TimerState.On)
.TriggeredBy(() => _onTimerInput);
builder.ConfigureState(TimerState.Pending)
.TriggeredBy(() => !_onTimerInput)
.WhenInState(TimerState.On);
builder.ConfigureState(TimerState.Off)
.TriggeredBy(() => !_onTimerInput)
.WhenInState(TimerState.Pending, () => TimeSpan.FromMilliseconds(dwellTimeInMs));
}).Builder();
[Theory]
[InlineData(true, 9, 0, TimerState.Off, TimerState.On)]
[InlineData(true, 9, 0, TimerState.Pending, TimerState.On)]
[InlineData(true, 9, 0, TimerState.On, TimerState.On)]
[InlineData(true, 1, 2, TimerState.Off, TimerState.On)]
[InlineData(true, 1, 2, TimerState.Pending, TimerState.On)]
[InlineData(true, 1, 2, TimerState.On, TimerState.On)]
[InlineData(false, 9, 0, TimerState.Off, TimerState.Off)]
[InlineData(false, 9, 0, TimerState.Pending, TimerState.Pending)]
[InlineData(false, 9, 0, TimerState.On, TimerState.Pending)]
[InlineData(false, 1, 2, TimerState.Off, TimerState.Off)]
[InlineData(false, 1, 2, TimerState.Pending, TimerState.Off)]
[InlineData(false, 1, 2, TimerState.On, TimerState.Pending)]
public async Task Example_Usage_OffTimerConfiguration_Run_async(bool timerInput, int dwellTimeInMs, int sleepTimeInMs, TimerState currentState, TimerState expectedState)
{
_sequence = GetOffTimerConfiguration(dwellTimeInMs).Build();
_onTimerInput = timerInput;
_sequence.SetState(currentState);
await Task.Delay(sleepTimeInMs);
await _sequence.RunAsync();
var actual = _sequence.CurrentState;
actual.ShouldBe(expectedState);
}
}For more examples -> IntegrationTestsFluentSeq/Examples
States can be defined as strings, enums, int, objects, and so on.
Internally they will be stored as type SeqState.
var builder = new FluentSeq<TimerState>().Create(TimerState.Off)
.ConfigureState(TimerState.Off)
.Builder()
// or
var builder = new FluentSeq<string>().Create("Off")
.ConfigureState("Off")
.Builder()TBD
TBD
The validation process ensures the sequence configuration is complete and adheres to the defined principles.
By default, validation is enabled but can be disabled either entirely or for specific states.
The sequence is validated during the build process.
To build a sequence:
_sequence = builder.Build();
Validation Principles:
- A sequence must have at least two configured states.
- The initial state must be defined and configured (not null or empty).
- Every state must have a TriggeredBy(...) method.
- Every TriggeredBy().WhenInState(s)(...) must point to a configured state.
Validation could be disabled:
- completely turn off validation
var builder = new FluentSeq<TimerState>().Create(TimerState.Off)
.DisableValidation()
.ConfigureState(TimerState.Off)
.Builder()- or with specifying states that shouldn't be validated:
var builder = new FluentSeq<TimerState>().Create(Enum.Off)
.DisableValidationForStates(Enum.State1, Enum.State2, ...)
.ConfigureState(Enum.Off)
.Builder()