Handle when exceptions have no error messages. (pester#1382)

* Handle when exceptions have no error messages.
AndyDLP · Oct 8, 2019 · 2f5b40c · 2f5b40c
1 parent b466a53
commit 2f5b40c
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Showing 2 changed files with 35 additions and 2 deletions.
diff --git a/Functions/Output.Tests.ps1 b/Functions/Output.Tests.ps1
@@ -1,4 +1,4 @@
-Set-StrictMode -Version Latest
+Set-StrictMode -Version Latest
 
 InModuleScope -ModuleName Pester -ScriptBlock {
     Describe 'Has-Flag' -Fixture {
@@ -367,6 +367,39 @@ InModuleScope -ModuleName Pester -ScriptBlock {
                     }
                 }
             }
+
+            Context 'Exceptions with no error message property set' {
+                $powershellVersion = $($PSVersionTable.PSVersion.Major)
+                try {
+                    $exceptionWithNullMessage = New-Object -TypeName "System.Management.Automation.ParentContainsErrorRecordException"
+                    throw $exceptionWithNullMessage
+                }
+                catch {
+                    $exception = $_
+                }
+                $result = $exception | ConvertTo-FailureLines
+
+                if ($powershellVersion -lt 3) {
+                    # Necessary because Microsoft changed the behaviour of System.Management.Automation.ParentContainsErrorRecordException at this point.
+                    It 'produces correct message lines' {
+                        $result.Message.Length | Should -Be 2
+                    }
+
+                    It 'produces correct trace line' {
+                        $result.Trace.Count | Should -Be 1
+                    }
+                }
+                else {
+                    It 'produces correct message lines' {
+                        $result.Message.Length | Should -Be 0
+                    }
+
+                    It 'produces correct trace line' {
+                        $result.Trace.Count | Should -Be 1
+                    }
+                }
+            }
+
         }
     }
 }
diff --git a/Functions/Output.ps1 b/Functions/Output.ps1
@@ -479,7 +479,7 @@ function ConvertTo-FailureLines {
         while ($exception) {
             $exceptionName = $exception.GetType().Name
             $thisLines = $exception.Message.Split([string[]]($([System.Environment]::NewLine), "\n", "`n"), [System.StringSplitOptions]::RemoveEmptyEntries)
-            if ($ErrorRecord.FullyQualifiedErrorId -ne 'PesterAssertionFailed') {
+            if ($ErrorRecord.FullyQualifiedErrorId -ne 'PesterAssertionFailed' -and $thisLines.Length -gt 0) {
                 $thisLines[0] = "$exceptionName`: $($thisLines[0])"
             }
             [array]::Reverse($thisLines)