Fluent assertion for OR condition

问题

I am trying to set up the fluent assertion for the below condition. But couldnt find a method with expression or an ObjectAssertion with Or().

I got to check the status of my service is of enum value Pending or Active

services.Should().HaveCount(totalServices).And.BeOfType<Service>().Which.ServiceStatusKey.Should().Be(Status.Pending);

I want something like,

.Be(Status.Pending).Or().Be(Status.Active)

Could someone please help me achieving this.

FluentAsserstions Version : 4.1.1 (Latest from Nuget) Attaching the 4.1 FluentAssertions.Primitive namespace.

 // Decompiled with JetBrains decompiler
// Type: FluentAssertions.Primitives.ObjectAssertions
// Assembly: FluentAssertions.Core, Version=4.1.1.0, Culture=neutral, PublicKeyToken=33f2691a05b67b6a
// MVID: 090116C5-E9A5-4878-B62E-DE0EBFEBBE14
// Assembly location: C:\RA\P4V\BOSS\trunk\M5Portal\packages\FluentAssertions.4.1.1\lib\net45\FluentAssertions.Core.dll

using FluentAssertions;
using FluentAssertions.Common;
using FluentAssertions.Execution;
using System;
using System.Diagnostics;

namespace FluentAssertions.Primitives
{
  /// <summary>
  /// Contains a number of methods to assert that an <see cref="T:System.Object"/> is in the expected state.
  /// 
  /// </summary>
  [DebuggerNonUserCode]
  public class ObjectAssertions : ReferenceTypeAssertions<object, ObjectAssertions>
  {
    /// <summary>
    /// Returns the type of the subject the assertion applies on.
    /// 
    /// </summary>
    protected override string Context
    {
      get
      {
        return "object";
      }
    }

    public ObjectAssertions(object value)
    {
      this.Subject = value;
    }

    /// <summary>
    /// Asserts that an object equals another object using its <see cref="M:System.Object.Equals(System.Object)"/> implementation.
    /// 
    /// </summary>
    /// <param name="expected">The expected value</param><param name="because">A formatted phrase as is supported by <see cref="M:System.String.Format(System.String,System.Object[])"/> explaining why the assertion
    ///             is needed. If the phrase does not start with the word <i>because</i>, it is prepended automatically.
    ///             </param><param name="reasonArgs">Zero or more objects to format using the placeholders in <see cref="!:because"/>.
    ///             </param>
    public AndConstraint<ObjectAssertions> Be(object expected, string because = "", params object[] reasonArgs)
    {
      Execute.Assertion.BecauseOf(because, reasonArgs).ForCondition(ObjectExtensions.IsSameOrEqualTo(this.Subject, expected)).FailWith("Expected {context:object} to be {0}{reason}, but found {1}.", expected, this.Subject);
      return new AndConstraint<ObjectAssertions>(this);
    }

    /// <summary>
    /// Asserts that an object does not equal another object using its <see cref="M:System.Object.Equals(System.Object)"/> method.
    /// 
    /// </summary>
    /// <param name="unexpected">The unexpected value</param><param name="because">A formatted phrase explaining why the assertion should be satisfied. If the phrase does not
    ///             start with the word <i>because</i>, it is prepended to the message.
    ///             </param><param name="reasonArgs">Zero or more values to use for filling in any <see cref="M:System.String.Format(System.String,System.Object[])"/> compatible placeholders.
    ///             </param>
    public AndConstraint<ObjectAssertions> NotBe(object unexpected, string because = "", params object[] reasonArgs)
    {
      Execute.Assertion.ForCondition(!ObjectExtensions.IsSameOrEqualTo(this.Subject, unexpected)).BecauseOf(because, reasonArgs).FailWith("Did not expect {context:object} to be equal to {0}{reason}.", unexpected);
      return new AndConstraint<ObjectAssertions>(this);
    }

    /// <summary>
    /// Asserts that an object is an enum and has a specified flag
    /// 
    /// </summary>
    /// <param name="expectedFlag">The expected flag.</param><param name="because">A formatted phrase explaining why the assertion should be satisfied. If the phrase does not
    ///             start with the word <i>because</i>, it is prepended to the message.
    ///             </param><param name="reasonArgs">Zero or more values to use for filling in any <see cref="M:System.String.Format(System.String,System.Object[])"/> compatible placeholders.
    ///             </param>
    public AndConstraint<ObjectAssertions> HaveFlag(Enum expectedFlag, string because = "", params object[] reasonArgs)
    {
      Execute.Assertion.BecauseOf(because, reasonArgs).ForCondition(this.Subject != null).FailWith("Expected type to be {0}{reason}, but found <null>.", (object) expectedFlag.GetType()).Then.ForCondition(this.Subject.GetType() == expectedFlag.GetType()).FailWith("Expected the enum to be of type {0} type but found {1}{reason}.", (object) expectedFlag.GetType(), (object) this.Subject.GetType()).Then.Given<Enum>((Func<Enum>) (() => this.Subject as Enum)).ForCondition((Func<Enum, bool>) (@enum => @enum.HasFlag(expectedFlag))).FailWith("The enum was expected to have flag {0} but found {1}{reason}.", (Func<Enum, object>) (_ => (object) expectedFlag), (Func<Enum, object>) (@enum => (object) @enum));
      return new AndConstraint<ObjectAssertions>(this);
    }

    /// <summary>
    /// Asserts that an object is an enum and does not have a specified flag
    /// 
    /// </summary>
    /// <param name="unexpectedFlag">The unexpected flag.</param><param name="because">A formatted phrase explaining why the assertion should be satisfied. If the phrase does not
    ///             start with the word <i>because</i>, it is prepended to the message.
    ///             </param><param name="reasonArgs">Zero or more values to use for filling in any <see cref="M:System.String.Format(System.String,System.Object[])"/> compatible placeholders.
    ///             </param>
    public AndConstraint<ObjectAssertions> NotHaveFlag(Enum unexpectedFlag, string because = "", params object[] reasonArgs)
    {
      Execute.Assertion.BecauseOf(because, reasonArgs).ForCondition(this.Subject != null).FailWith("Expected type to be {0}{reason}, but found <null>.", (object) unexpectedFlag.GetType()).Then.ForCondition(this.Subject.GetType() == unexpectedFlag.GetType()).FailWith("Expected the enum to be of type {0} type but found {1}{reason}.", (object) unexpectedFlag.GetType(), (object) this.Subject.GetType()).Then.Given<Enum>((Func<Enum>) (() => this.Subject as Enum)).ForCondition((Func<Enum, bool>) (@enum => !@enum.HasFlag(unexpectedFlag))).FailWith("Did not expect the enum to have flag {0}{reason}.", new object[1]
      {
        (object) unexpectedFlag
      });
      return new AndConstraint<ObjectAssertions>(this);
    }
  }
}

回答1:

You can use Match for this case.

ServiceStatusKey.Should().Match<Status>(p=>p==Status.Pending || p == Status.Active);

FluentAssertions does not support an Or()-statement. Use Match() for general purpose assertions.

回答2:

Try this way:

(services.Status == Status.Pending || services.Status == Status.Active).Should().BeTrue("Message when it is false.");

回答3:

OR is a lot harder then AND, as what does

A().Or.B().And.C().Or.D()

mean?

The real problem is trying to support Or while also supporting And. Therefore I would be looking at writing a methods like

services.ShouldDoAtLeastOneof(params Predicate predicates)

as anything more flexible is questionable for asserts in unit tests.

(As I have never used Fluent Assertions, I don't know if it has a built in method that does this. I think the BeOneOf well solve the very limited case of "OR" asked for in the quesion, as shown in Matthew Watson's answer.)

来源：https://stackoverflow.com/questions/34654341/fluent-assertion-for-or-condition

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