(chocolatey#3051) Add tests for Get-ChocolateyPath

To ensure behaviour works as expected

tests/pester-tests/powershell-commands/Get-ChocolateyPath.Tests.ps1

@@ -0,0 +1,77 @@
+Describe 'Get-ChocolateyPath helper function tests' -Tags Cmdlets, GetChocolateyPath {
+    BeforeAll {
+        Initialize-ChocolateyTestInstall
+
+        $testLocation = Get-ChocolateyTestLocation
+        Import-Module "$testLocation\helpers\chocolateyInstaller.psm1"
+
+        if (-not $env:ChocolateyInstall) {
+            $env:ChocolateyInstall = $testLocation
+        }
+    }
+
+    Context '-PathType InstallPath' {
+        BeforeAll {
+            $programData = $env:ProgramData
+            $systemDrive = $env:SystemDrive
+        }
+
+        AfterAll {
+            $env:ChocolateyInstall = $testLocation
+            $env:ProgramData = $programData
+            $env:SystemDrive = $systemDrive
+        }
+
+        It 'Returns the value of $env:ChocolateyInstall if set' {
+            $env:ChocolateyInstall | Should -Not -BeNullOrEmpty -Because 'it should be set for this test'
+            Get-ChocolateyPath -PathType InstallPath | Should -BeExactly $env:ChocolateyInstall
+        }
+
+        It 'Falls back to $env:ProgramData\chocolatey if $env:ChocolateyInstall is not set' {
+            $env:ChocolateyInstall = ''
+            Get-ChocolateyPath -PathType InstallPath | Should -Be "$env:ProgramData\chocolatey"
+        }
+
+        It 'Falls back to $env:SystemDrive\ProgramData if $env:ChocolateyInstall and $env:ProgramData are not set' {
+            $env:ProgramData = ''
+            Get-ChocolateyPath -PathType InstallPath | Should -Be "$env:SystemDrive\ProgramData\chocolatey"
+        }
+
+        It 'Falls back to a path relative to the DLL location if none of the above are set' {
+            $env:SystemDrive = ''
+            Get-ChocolateyPath -PathType InstallPath | Should -Be $testLocation
+        }
+    }
+
+    Context '-PathType PackagePath' {
+        AfterEach {
+            $env:ChocolateyPackageFolder = ''
+            $env:PackageFolder = ''
+            $env:ChocolateyPackageName = ''
+        }
+
+        It 'Returns the value of $env:ChocolateyPackageFolder if set' {
+            $env:ChocolateyPackageFolder = 'C:\test'
+            Get-ChocolateyPath -PathType PackagePath | Should -BeExactly $env:ChocolateyPackageFolder
+        }
+
+        It 'Returns the value of $env:PackageFolder if set and $env:ChocolateyPackageFolder is not set' {
+            $env:PackageFolder = 'C:\test2'
+            Get-ChocolateyPath -PathType PackagePath | Should -BeExactly $env:PackageFolder
+        }
+
+        It 'Falls back to "{InstallPath}\lib\$env:ChocolateyPackageName" if neither of the PackageFolder variables are set' {
+            $env:ChocolateyPackageName = 'test'
+            $installPath = Get-ChocolateyPath -PathType InstallPath
+
+            $expectedPath = Join-Path -Path $installPath -ChildPath "lib\$env:ChocolateyPackageName"
+            Get-ChocolateyPath -PathType PackagePath | Should -Be $expectedPath
+        }
+    }
+
+    Context 'Invalid PathType' {
+        It 'Throws a ParameterBindingException' {
+            { Get-ChocolateyPath -PathType InvalidPath } | Should -Throw -ExceptionType 'System.Management.Automation.ParameterBindingException'
+        }
+    }
+}