Fix Should-Throw/Should -Throw to handle expected message with escaped wildcard

src/functions/assert/Exception/Should-Throw.ps1

@@ -25,6 +25,7 @@ function Should-Throw {
     ```powershell
     { throw 'error' } | Should-Throw
     { throw 'error' } | Should-Throw -ExceptionMessage 'error'
+    { throw 'wildcard character []' } | Should-Throw -ExceptionMessage '*character `[`]'
     { throw 'error' } | Should-Throw -ExceptionType 'System.Management.Automation.RuntimeException'
     { throw 'error' } | Should-Throw -FullyQualifiedErrorId 'RuntimeException'
     { throw 'error' } | Should-Throw -FullyQualifiedErrorId '*Exception'
@@ -100,7 +101,7 @@ function Should-Throw {
 
     $filterOnMessage = -not ([string]::IsNullOrWhiteSpace($ExceptionMessage))
     if ($filterOnMessage) {
-        $filters += "with message '$ExceptionMessage'"
+        $filters += "with message like '$([System.Management.Automation.WildcardPattern]::Unescape($ExceptionMessage))'"
         if ($err.ExceptionMessage -notlike $ExceptionMessage) {
             $buts += "the message was '$($err.ExceptionMessage)'"
         }

src/functions/assertions/PesterThrow.ps1

@@ -70,7 +70,9 @@
         # this is for Should -Not -Throw. Once *any* exception was thrown we should fail the assertion
         # there is no point in filtering the exception, because there should be none
         $succeeded = -not $actualExceptionWasThrown
-        if ($true -eq $succeeded) { return [Pester.ShouldResult]@{Succeeded = $succeeded } }
+        if ($true -eq $succeeded) {
+            return [Pester.ShouldResult]@{Succeeded = $succeeded }
+        }
 
         $failureMessage = "Expected no exception to be thrown,$(Format-Because $Because) but an exception `"$actualExceptionMessage`" was thrown $actualExceptionLine."
         return [Pester.ShouldResult] @{
@@ -96,7 +98,8 @@
 
     $filterOnMessage = -not [string]::IsNullOrWhitespace($ExpectedMessage)
     if ($filterOnMessage) {
-        $filters += "message like $(Format-Nicely $ExpectedMessage)"
+        $unescapedExpectedMessage = [System.Management.Automation.WildcardPattern]::Unescape($ExpectedMessage)
+        $filters += "message like $(Format-Nicely $unescapedExpectedMessage)"
         if ($actualExceptionWasThrown -and (-not (Get-DoValuesMatch $actualExceptionMessage $ExpectedMessage))) {
             $buts += "the message was $(Format-Nicely $actualExceptionMessage)"
         }
@@ -120,7 +123,12 @@
         $failureMessage = "Expected an exception$(if($filter) { " with $filter" }) to be thrown,$(Format-Because $Because) but $but. $actualExceptionLine".Trim()
 
         $ActualValue = $actualExceptionMessage
-        $ExpectedValue = if ($filterOnExceptionType) { "type $(Format-Nicely $ExceptionType)" } else { 'any exception' }
+        $ExpectedValue = if ($filterOnExceptionType) {
+            "type $(Format-Nicely $ExceptionType)"
+        }
+        else {
+            'any exception'
+        }
 
         return [Pester.ShouldResult] @{
             Succeeded      = $false

tst/functions/assert/Exception/Should-Throw.Tests.ps1

@@ -53,6 +53,10 @@ Describe "Should-Throw" {
         It "Fails when exception does not match the message with wildcard" {
             { { throw [ArgumentException]"A is null!" } | Should-Throw -ExceptionMessage '*flabbergasted*' } | Verify-AssertionFailed
         }
+
+        It "Passes when exception match the message with escaped wildcard" {
+            { throw [ArgumentException]"[]" } | Should-Throw -ExceptionMessage '`[`]'
+        }
     }
 
     Context "Filtering with FullyQualifiedErrorId" {
@@ -86,7 +90,7 @@ Describe "Should-Throw" {
 
         It "Given exception that does not match on message it returns the correct message" {
             $err = { { throw [ArgumentException]"fail!" } | Should-Throw -ExceptionMessage 'halt!' } | Verify-AssertionFailed
-            $err.Exception.Message | Verify-Equal "Expected an exception, with message 'halt!' to be thrown, but the message was 'fail!'."
+            $err.Exception.Message | Verify-Equal "Expected an exception, with message like 'halt!' to be thrown, but the message was 'fail!'."
         }
 
         It "Given exception that does not match on FullyQualifiedErrorId it returns the correct message" {
@@ -96,7 +100,7 @@ Describe "Should-Throw" {
 
         It "Given exception that does not match on type and message it returns the correct message" {
             $err = { { throw [ArgumentException]"fail!" } | Should-Throw -ExceptionType ([System.InvalidOperationException]) -ExceptionMessage 'halt!' } | Verify-AssertionFailed
-            $err.Exception.Message | Verify-Equal "Expected an exception, of type [InvalidOperationException], with message 'halt!' to be thrown, but the exception type was [ArgumentException] and the message was 'fail!'."
+            $err.Exception.Message | Verify-Equal "Expected an exception, of type [InvalidOperationException], with message like 'halt!' to be thrown, but the exception type was [ArgumentException] and the message was 'fail!'."
         }
 
         It "Given exception that does not match on type and FullyQualifiedErrorId it returns the correct message" {
@@ -106,12 +110,17 @@ Describe "Should-Throw" {
 
         It "Given exception that does not match on message and FullyQualifiedErrorId it returns the correct message" {
             $err = { { throw [ArgumentException]"halt!" } | Should-Throw -ExceptionMessage 'fail!'  -FullyQualifiedErrorId 'fail!' } | Verify-AssertionFailed
-            $err.Exception.Message | Verify-Equal "Expected an exception, with message 'fail!', with FullyQualifiedErrorId 'fail!' to be thrown, but the message was 'halt!' and the FullyQualifiedErrorId was 'halt!'."
+            $err.Exception.Message | Verify-Equal "Expected an exception, with message like 'fail!', with FullyQualifiedErrorId 'fail!' to be thrown, but the message was 'halt!' and the FullyQualifiedErrorId was 'halt!'."
         }
 
         It "Given exception that does not match on type, message and FullyQualifiedErrorId it returns the correct message" {
             $err = { { throw [ArgumentException]"halt!" } | Should-Throw -ExceptionType ([System.InvalidOperationException]) -ExceptionMessage 'fail!'  -FullyQualifiedErrorId 'fail!' } | Verify-AssertionFailed
-            $err.Exception.Message | Verify-Equal "Expected an exception, of type [InvalidOperationException], with message 'fail!' and with FullyQualifiedErrorId 'fail!' to be thrown, but the exception type was [ArgumentException], the message was 'halt!' and the FullyQualifiedErrorId was 'halt!'."
+            $err.Exception.Message | Verify-Equal "Expected an exception, of type [InvalidOperationException], with message like 'fail!' and with FullyQualifiedErrorId 'fail!' to be thrown, but the exception type was [ArgumentException], the message was 'halt!' and the FullyQualifiedErrorId was 'halt!'."
+        }
+
+        It "Given exception that does not match on a message with escaped wildcard it returns the correct message" {
+            $err = { { throw [ArgumentException]"[!]" } | Should-Throw -ExceptionMessage '`[`]' } | Verify-AssertionFailed
+            $err.Exception.Message | Verify-Equal "Expected an exception, with message like '[]' to be thrown, but the message was '[!]'."
         }
     }
 

tst/functions/assertions/PesterThrow.Tests.ps1

@@ -164,6 +164,18 @@ InPesterModuleScope {
                 $err.Exception.Message | Verify-Equal "Expected an exception with FullyQualifiedErrorId 'id' to be thrown, but no exception was thrown."
             }
 
+            It "returns the correct assertion message when message filter is used and contain escaped wildcard character" {
+                $testDrive = (Get-PSDrive TestDrive).Root
+                $testScriptPath = Join-Path $testDrive test.ps1
+                Set-Content -Path $testScriptPath -Value "throw [ArgumentException]'[!]'"
+
+                # use the real path of the script, because we don't know it beforehand
+                $assertionMessage = "Expected an exception with message like '[]' to be thrown, but the message was '[!]'. from ##path##:1 char:" -replace "##path##", $testScriptPath
+
+                $err = { { & $testScriptPath } | Should -Throw -ExpectedMessage '`[`]' } | Verify-AssertionFailed
+                $err.Exception.Message -replace "(`r|`n)" -replace '\s+', ' ' -replace '(char:).*$', '$1' | Verify-Equal $assertionMessage
+            }
+
             It 'returns the correct assertion message when exceptions messages differ' {
                 $testDrive = (Get-PSDrive TestDrive).Root
                 $testScriptPath = Join-Path $testDrive test.ps1