我正在编写一些Pester测试用例,并查看CodeCoverage结果。在大多数包含try/catch的测试用例集中,我们会发现catch部分的代码覆盖率为0%。以下是一个示例:
function Test-Is64Bit()
{
$Result = $false
try
{
if ((Get-WmiObject -Class "Win32_OperatingSystem").OSArchitecture -eq '64-bit')
{
$Result = $true
}
}
catch
{
Write-Error $_.Exception | Format-List -Force
}
return $Result
}
很容易嘲笑Get-WmiObject返回值来测试$true条件。
我已经尝试了许多想法来模拟从Get-WmiObject引发异常,但在每种情况下,异常都会传递到控制台而不是被Pester捕获并通过测试。以下是我最好的解决方案,但仍然不起作用。
Context "Unit tests for Get-WmiObject exception" {
# mock the Get-WmiObject cmdlet for unit testing
Mock Get-WmiObject {
Throw
} -ParameterFilter { $Class -And $Class -eq 'Win32_OperatingSystem' }
It "Function test passes" {
{ Test-Is64Bit } | Should Be $false
Assert-MockCalled Get-WmiObject -Scope It -Exactly -Times 1
}
}
这个测试的结果为:
Context Unit tests for Get-WmiObject error
[-] Function test passes 138ms
Expected: {False}
But was: { Test-Is64Bit }
at line: 62 in .\Tests\Test-Is64Bit.Tests.ps1
62: { Test-Is64Bit } | Should Be $false
Tests completed in 590ms
Tests Passed: 4 Failed: 1 Skipped: 0 Pending: 0 Inconclusive: 0
Code coverage report:
Covered 80.00 % of 10 analyzed Commands in 1 File.
Missed commands:
File Function Line Command
---- -------- ---- -------
Test-Is64Bit.ps1 Test-Is64Bit 38 Write-Error $_.Exception
Test-Is64Bit.ps1 Test-Is64Bit 38 Format-List -Force
有没有方法可以模拟 Get-WmiObject 抛出异常,以便我们可以让 Pester 进入 catch,并最终实现100%的代码覆盖率?
我目前的测试代码正在寻找异常。
Context "Unit tests for Get-WmiObject exception" {
# mock the Get-WmiObject cmdlet for unit testing
Mock Get-WmiObject {
Throw 'Some Error'
} -ParameterFilter { $Class -And $Class -eq 'Win32_OperatingSystem' }
It 'Get-WmiObject should throw' {
{ Get-WmiObject -Class 'Win32_OperatingSystem' } | Should Throw 'Some Error'
}
It "Throws exception" {
{ Test-Is64Bit } | Should Throw 'Some Error'
Assert-MockCalled Get-WmiObject -Scope It -Exactly -Times 1
}
}
上述代码的结果如下:
Context Unit tests for Get-WmiObject exception
[+] Get-WmiObject should throw 89ms
Test-Is64Bit : System.Management.Automation.RuntimeException: Some Error At
C:\ONESolutionFinance\Main\ReleaseManagement\PowerShell-Module\SPSNoDeps\Tests\Test-Is64Bit.Tests.ps1:66
char:7
+ { Test-Is64Bit } | Should Throw 'Some Error'
+ ~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Write-Error], WriteErrorException
+ FullyQualifiedErrorId : Microsoft.PowerShell.Commands.WriteErrorException,Test-Is64Bit
[-] Throws exception 51ms
Expected: the expression to throw an exception with message {Some Error}, an exception was not raised, message was {}
from line:2 char:5
+ Throw 'Some Error'
+ ~~~~~~~~~~~~~~~~~~
at line: 66 in C:\ONESolutionFinance\Main\ReleaseManagement\PowerShell-Module\SPSNoDeps\Tests\Test-Is64Bit.Tests.ps1
66: { Test-Is64Bit } | Should Throw 'Some Error'
测试$false的结果如下:
Context Unit tests for Get-WmiObject exception
[+] Get-WmiObject should throw 162ms
Test-Is64Bit : System.Management.Automation.RuntimeException: Some Error
At C:\ONESolutionFinance\Main\ReleaseManagement\PowerShell-Module\SPSNoDeps\Tests\Test-Is64Bit.Tests.ps1:66 char:5
+ Test-Is64Bit | Should Be $false
+ ~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Write-Error], WriteErrorException
+ FullyQualifiedErrorId : Microsoft.PowerShell.Commands.WriteErrorException,Test-Is64Bit
[+] Throws exception 92ms
Test-Is64Bit | Should Be $false
。 - Mark Wragg$Class -And $Class -eq 'Win32_OperatingSystem'
更改为$Class -eq 'Win32_OperatingSystem'
。前者似乎是不必要的,可能会阻止Mock被调用。我假设Assert-MockCalled也显示了这一点?它在你上面的输出中没有出现。 - Mark Wragg