Pester测试未调用模拟Invoke-RestMethod，仍调用真实函数问题

概要：为Invoke-RestMethod设置Mock后，测试仍调用其真实实现而非模拟函数。

环境信息 #

• Pester版本：5.6.1（路径：C:\Program Files\WindowsPowerShell\Modules\Pester\5.6.1\Pester.psm1）
• PowerShell版本：5.1.19041.4648
• 操作系统版本：Microsoft Windows NT 10.0.19045.0

复现示例 #

所有文件位于同一目录：

Client.psm1 #

class Client
{
    [string] $Query

    Client([string] $query) 
    {
        $this.Query = $query
    }


    [string] Google()
    {
        $url = "https://www.google.com/?q=$($this.Query)"
    
        $response = Invoke-RestMethod -Uri $url `
                                        -Method GET
        
        return $response                                     
    }
}

Client.Tests.ps1 #

using module .\Client.psm1

Describe "Client_Tests" {    

    It "Google_queryIsPopulated_ReturnsSearchResultsContainingQuery" {            
        # Arrange
        $givenQuery = "fooBar"
        $expectedResult = "fooBar"

        Mock Invoke-RestMethod { 
            $givenQuery 
        } 

        $systemUnderTest = [Client]::new($givenQuery)        
        
        # Act
        $actualResults = $systemUnderTest.Google() 

        # Assert
        $actualResults | Should -Be $expectedResult        
    }
}

测试错误输出 #

执行命令Invoke-Pester .\Client.Tests.ps1后得到以下错误：

Starting discovery in 1 files.
Discovery found 1 tests in 53ms.
Running tests.
[-] Client_Tests.Google_queryIsPopulated_ReturnsSearchResultsContainingQuery 478ms (476ms|2ms)
 Expected strings to be the same, but they were different.
 Expected length: 6
 Actual length:   54403
 Strings differ at index 0.
 Expected: 'fooBar'
 But was:  '<!doctype html><html itemscope="" itemtype="http://schema.org/WebPage" lang="en"><head><meta content...'
            ^
 at $actualResults | Should -Be $expectedResult, C:\Users\dgleason\Downloads\example for mock invoke-restmethod\v1\Client.Tests.ps1:21
 at <ScriptBlock>, C:\Users\dgleason\Downloads\example for mock invoke-restmethod\v1\Client.Tests.ps1:21
Tests completed in 602ms
Tests Passed: 0, Failed: 1, Skipped: 0, Inconclusive: 0, NotRun: 0

内容的提问来源于stack exchange，提问作者Devin Gleason Lambert