如何在 Pester 中将两个数组与自定义对象进行比较

Question

我们正在努力让 Pester 测试失败或通过，这取决于 array 中 objects 的相等性。

测试。ps1

#require Assert
#require Pester

$Expected = @(
    [PSCustomObject]@{Name1 = 'Text1';Name2 = 'Text2'}
    [PSCustomObject]@{Name1 = 'Text1';Name2 = 'Text2'}
)
$Actual = @(
    [PSCustomObject]@{Name1 = 'Text1';Name2 = 'Text2'}
    [PSCustomObject]@{Name1 = 'Text1';Name2 = 'Text2'}
)

Describe 'comparing arrays' {
    Context 'Assert-Equivalent' {
        it 'should be green' {           
            Assert-Equivalent -Actual $Expected -Expected $Expected
        }
        it 'should be green' {        
            Assert-Equivalent -Actual $Actual -Expected $Expected
        }
        it 'should be red' {        
            $Wrong = @(
                [PSCustomObject]@{Name1 = 'Text1';Name2 = 'Text2'}
                [PSCustomObject]@{Name1 = 'WROMG';Name2 = 'Text2'}
            )
            Assert-Equivalent -Actual $Wrong -Expected $Expected
        }
    }
    Context 'Should be' {
        it 'should be green' {
            $Expected | Should -Be $Expected
        }
        it 'should be green' {
            $Actual | Should -Be $Expected
        }
        it 'should be red' {        
            $Wrong = @(
                [PSCustomObject]@{Name1 = 'Text1';Name2 = 'Text2'}
                [PSCustomObject]@{Name1 = 'WROMG';Name2 = 'Text2'}
            )
            $Wrong | Should -Be $Expected
        }
    }
}

我们似乎做错了。我们是否使用了错误的 CmdLets？或者还有另一种检查方法吗？有时 array 也只是另一个对象的属性。因此需要进行深入比较。

Answer 1

当我想将某些 'complex' 对象与 Pester 进行比较时，我使用 ConvertTo-Json。这并不理想，因为如果类型不匹配可能会出现一些假阴性，但它通常可以完成工作。

$Expected = @(
    [PSCustomObject]@{Name1 = 'Text1';Name2 = 'Text2'}
    [PSCustomObject]@{Name1 = 'Text1';Name2 = 'Text2'}
)
$Actual = @(
    [PSCustomObject]@{Name1 = 'Text1';Name2 = 'Text2'}
    [PSCustomObject]@{Name1 = 'Text1';Name2 = 'Text2'}
)

Describe 'comparing arrays' {
    Context 'Assert-Equivalent' {
        it 'should be green' {           
            Assert-Equivalent -Actual ($Expected | ConvertTo-Json)  -Expected ($Expected | ConvertTo-Json) 
        }
        it 'should be green' {        
            Assert-Equivalent -Actual ($Actual | ConvertTo-Json)  -Expected ($Expected | ConvertTo-Json) 
        }
        it 'should be red' {        
            $Wrong = @(
                [PSCustomObject]@{Name1 = 'Text1';Name2 = 'Text2'}
                [PSCustomObject]@{Name1 = 'WROMG';Name2 = 'Text2'}
            )
            Assert-Equivalent -Actual ($Wrong | ConvertTo-Json)  -Expected ($Expected | ConvertTo-Json) 
        }
    }
    Context 'Should be' {
        it 'should be green' {
            ($Expected | ConvertTo-Json) | Should -Be ($Expected | ConvertTo-Json)
        }
        it 'should be green' {
            ($Actual | ConvertTo-Json) | Should -Be ($Expected | ConvertTo-Json)
        }
        it 'should be red' {        
            $Wrong = @(
                [PSCustomObject]@{Name1 = 'Text1';Name2 = 'Text2'}
                [PSCustomObject]@{Name1 = 'WROMG';Name2 = 'Text2'}
            )
            ($Wrong | ConvertTo-Json) | Should -Be ($Expected | ConvertTo-Json)
        }
    }
}

Answer 2

这也取决于你想在这个问题上有多严格，例如：

数组中对象的顺序重要吗？
您要对属性进行类型转换吗？

反正我为此写了一个小帮手：

Function Should-BeObject {
    Param (
        [Parameter(Position=0)][Object[]]$b, [Parameter(ValueFromPipeLine = $True)][Object[]]$a
    )
    $Property = ($a | Select-Object -First 1).PSObject.Properties | Select-Object -Expand Name
    $Difference = Compare-Object $b $a -Property $Property
    Try {"$($Difference | Select-Object -First 1)" | Should -BeNull} Catch {$PSCmdlet.WriteError($_)}
}

您可以这样调用它：

,$Actual | Should-BeObject $Expected

_{(注意,$Actual前面的逗号)}

Answer 3

我自己没有尝试过，但是 https://github.com/nohwnd/Assert 库中有一个 Assert-Equivalent cmdlet 看起来很有前途。

Answer 4

虽然这是一个老问题，但我想展示另一种方法来做到这一点。 Compare-Object 在比较复杂对象时会派上用场。


$Expected = @(
    [PSCustomObject]@{Name1 = 'Text1'; Name2 = 'Text2' }
    [PSCustomObject]@{Name1 = 'Text1'; Name2 = 'Text2' }
)
$Actual = @(
    [PSCustomObject]@{Name1 = 'Text1'; Name2 = 'Text2' }
    [PSCustomObject]@{Name1 = 'Text1'; Name2 = 'Text2' }
)

Describe 'object equivalence' {
    It 'eq' {
        $eqs = $Actual | Compare-Object -ReferenceObject $Expected -Property @('Name1', 'Name2') -IncludeEqual | Select-Object -ExpandProperty SideIndicator
        $eqs | ForEach-Object { $_ | Should -Be '==' }
    }
}

请注意，您需要指定要比较的所有属性。多看看 here.

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