Fix function definition in parameter filter (#1293)

Allow ${function:} to be passed to Mock -ParameterFilter
pester · May 1, 2019 · ea65cc6 · ea65cc6
1 parent c300092
commit ea65cc6
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Showing 2 changed files with 103 additions and 4 deletions.
diff --git a/Functions/Mock.Tests.ps1 b/Functions/Mock.Tests.ps1
@@ -2216,11 +2216,92 @@ Describe "Mock definition output" {
     }
 }
 
-Describe 'Mocking using ParameterFilter with scriptblock' {
-    $filter = [scriptblock]::Create( ('$Path -eq ''C:\Windows''') )
-    Mock -CommandName 'Test-Path' -ParameterFilter $filter
+Describe 'Mocking using ParameterFilter' {
+
+    Context 'Scriptblock [Scriptblock]::Create() passed to ParameterFilter as var' {
+        BeforeAll{
+            $filter = [scriptblock]::Create( ('$Path -eq ''C:\Windows''') )
+            Mock Test-Path { $True }
+            Mock Test-Path -ParameterFilter $filter -MockWith { $False }
+        }
+
+        It "Returns default mock" {
+            Test-Path -Path C:\AwesomePath | Should -Be $True
+        }
+
+        It "returns mock that matches parameter filter block" {
+            Test-Path -Path C:\Windows | Should -Be $false
+        }
+    }
+
+    Context 'Scriptblock expression $( [Scriptblock]::Create() ) passed to ParameterFilter' {
+        BeforeAll{
+            $filter = [scriptblock]::Create( ('$Path -eq ''C:\Windows''') )
+            Mock Test-Path { $True }
+            Mock Test-Path -ParameterFilter $( [scriptblock]::Create(('$Path -eq ''C:\Windows''')) ) -MockWith { $False }
+        }
+
+        It "Returns default mock" {
+            Test-Path -Path C:\AwesomePath | Should -Be $True
+        }
+
+        It "returns mock that matches parameter filter block" {
+            Test-Path -Path C:\Windows | Should -Be $false
+        }
+    }
+
+    Context 'Scriptblock {} passed to ParameterFilter' {
+        BeforeAll{
+            Mock Test-Path { $True }
+            Mock Test-Path -ParameterFilter { $Path -eq "C:\Windows" } -MockWith { $False }
+        }
+
+        It "Returns default mock" {
+            Test-Path -Path C:\AwesomePath | Should -Be $True
+        }
+
+        It "returns mock that matches parameter filter block" {
+            Test-Path -Path C:\Windows | Should -Be $false
+        }
+    }
+    Context 'Scriptblock {} passed to ParameterFilter as var' {
+        BeforeAll{
+            $filter = {
+                $Path -eq "C:\Windows"
+            }
+            Mock Test-Path { $True }
+            Mock Test-Path -ParameterFilter $filter -MockWith { $False }
+        }
+
+        It "Returns default mock" {
+            Test-Path -Path C:\AwesomePath | Should -Be $True
+        }
+
+        It "returns mock that matches parameter filter block" {
+            Test-Path -Path C:\Windows | Should -Be $false
+        }
+    }
+
+    Context 'Function Definition ${} passed to ParameterFilter' {
+        BeforeAll {
+            Function ParamFilter {
+                $Path -eq "C:\Windows"
+            }
+            Mock Test-Path { $True }
+            Mock Test-Path -ParameterFilter ${function:ParamFilter} -MockWith { $False }
+        }
+
+        It "Returns default mock" {
+            Test-Path -Path C:\AwesomePath | Should -Be $True
+        }
+
+        It "returns mock that matches parameter filter block" {
+            Test-Path -Path C:\Windows | Should -Be $false
+        }
+    }
 }
 
+
 if ($PSVersionTable.PSVersion.Major -ge 3) {
     Describe "-RemoveParameterType" {
         BeforeAll {

diff --git a/Functions/Mock.ps1 b/Functions/Mock.ps1
@@ -1642,6 +1642,24 @@ function Get-ConflictingParameterNames {
     $script:ConflictingParameterNames
 }
 
+function Get-ScriptBlockAST {
+    param (
+        [scriptblock]
+        $ScriptBlock
+    )
+
+    if ($ScriptBlock.Ast -is [System.Management.Automation.Language.ScriptBlockAst]) {
+        $ast = $Block.Ast.EndBlock
+    }
+    elseif ($ScriptBlock.Ast -is [System.Management.Automation.Language.FunctionDefinitionAst]) {
+        $ast = $Block.Ast.Body.EndBlock
+    }
+    else {
+        throw "Pester failed to parse ParameterFilter, scriptblock is invalid type. Please reformat your ParameterFilter."
+    }
+
+    return $ast
+}
 
 function New-BlockWithoutParameterAliases {
     [CmdletBinding()]
@@ -1659,7 +1677,7 @@ function New-BlockWithoutParameterAliases {
     try {
         if ($PSVersionTable.PSVersion.Major -ge 3) {
             $params = $Metadata.Parameters.Values
-            $ast = $Block.Ast.EndBlock
+            $ast = Get-ScriptBlockAST $Block
             $blockText = $ast.Extent.Text
             $variables = [array]($Ast.FindAll( { param($ast) $ast -is [System.Management.Automation.Language.VariableExpressionAst]}, $true))
             [array]::Reverse($variables)