hardcoding Pester v4 (#46)

* Update InvokeTests.ps1

* Update InvokeTests.ps1

Author: iricigor

tools/InvokeTests.ps1

@@ -8,10 +8,18 @@ param (
     [string]$TestsToRun
 )
 
-function InstallModule ([string]$Name,[version]$Version){
-    if (!(Get-Module $Name -List | where Version -ge $Version)) {
-        Write-Host "Installing $Name"
-        Install-Module -Name $Name -Force -SkipPublisherCheck -Scope CurrentUser -Repository PSGallery
+function InstallModule ([string]$Name,[version]$Version,[version]$MaxVersion=$null){
+    if ($MaxVersion) {
+        if (!(Get-Module $Name -List | where Version -ge $Version | where Version -le $MaxVersion)) {
+            Write-Host "Installing $Name with Max Version $MaxVersion"
+            Install-Module -Name $Name -Force -SkipPublisherCheck -Scope CurrentUser -Repository PSGallery -MaximumVersion $MaxVersion
+        }
+        Import-Module $Name -MaximumVersion $MaxVersion
+    } else {
+        if (!(Get-Module $Name -List | where Version -ge $Version)) {
+            Write-Host "Installing $Name"
+            Install-Module -Name $Name -Force -SkipPublisherCheck -Scope CurrentUser -Repository PSGallery
+        }
         Import-Module $Name
     }
     if ($env:TF_BUILD) {Get-Module $Name -List}
@@ -32,7 +40,7 @@ if ($env:TF_BUILD) {
 # Install Pester and Platy, if needed
 #
 
-InstallModule Pester '4.0.0'
+InstallModule Pester '4.0.0' '4.99'
 InstallModule PlatyPS '0.14.0'
 InstallModule PSScriptAnalyzer '1.17.0'
 
@@ -53,4 +61,4 @@ switch ($TestsToRun) {
 
 Write-Host "Run Pester tests"
 $Result = Invoke-Pester -Path "$tests/module", "$tests/functions" -Tag $Tags -PassThru -OutputFile PesterTestResults.xml
-if ($Result.failedCount -ne 0) {Write-Error "Pester returned errors"}
+if ($Result.failedCount -ne 0) {Write-Error "Pester returned errors"}