流利断言:近似比较类属性

时间:2016-04-22 01:09:04

标签: c# unit-testing fluent-assertions

我有一个类Vector3D,其类型为XYZ类型为double(它还有其他属性,例如Magnitude

使用Fluent Assertions以给定精度近似比较所有属性或属性选择的最佳方法是什么?

目前我一直在这样做:

calculated.X.Should().BeApproximately(expected.X, precision);
calculated.Y.Should().BeApproximately(expected.Y, precision);
calculated.Z.Should().BeApproximately(expected.Z, precision);

是否有单线方法可以达到同样的效果?例如使用ShouldBeEquivalentTo,或者这是否需要构建允许包含/排除属性的通用扩展方法?

1 个答案:

答案 0 :(得分:8)

是的,可以使用ShouldBeEquivalentTo。以下代码将检查所有属性为double的属性,精度为0.1:

double precision = 0.1;
calculated.ShouldBeEquivalentTo(expected, option => options
    .Using<double>(ctx => ctx.Subject.Should().BeApproximately(ctx.Expectation, precision))
    .WhenTypeIs<double>());

如果您只想比较X,Y和Z属性,请更改When约束,如下所示:

double precision = 0.1;
calculated.ShouldBeEquivalentTo(b, options => options
    .Using<double>(ctx => ctx.Subject.Should().BeApproximately(ctx.Expectation, precision))
    .When(info => info.SelectedMemberPath == "X" ||
                  info.SelectedMemberPath == "Y" ||
                  info.SelectedMemberPath == "Z"));

另一种方法是明确告诉FluentAssertions应该比较属性,但它不那么优雅:

double precision = 0.1;
calculated.ShouldBeEquivalentTo(b, options => options
    .Including(info => info.SelectedMemberPath == "X" ||
                           info.SelectedMemberPath == "Y" ||
                           info.SelectedMemberPath == "Z")
    .Using<double>(ctx => ctx.Subject.Should().BeApproximately(ctx.Expectation, precision))
    .When(info => true));

由于Using语句不返回EquivalencyAssertionOptions<T>,我们需要通过使用始终为真的表达式调用When语句来破解它。