Allow using a folder path in WebCmdlet's OutFile parameter (#19007)

src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/Common/InvokeRestMethodCommand.Common.cs

@@ -135,8 +135,12 @@ namespace Microsoft.PowerShell.Commands
                 }
             }
             else if (ShouldSaveToOutFile)
-            {
-                StreamHelper.SaveStreamToFile(baseResponseStream, QualifiedOutFile, this, response.Content.Headers.ContentLength.GetValueOrDefault(), _cancelToken.Token);
+            {   
+                string outFilePath = WebResponseHelper.GetOutFilePath(response, _qualifiedOutFile);
+
+                WriteVerbose(string.Create(System.Globalization.CultureInfo.InvariantCulture, $"File Name: {Path.GetFileName(_qualifiedOutFile)}"));
+
+                StreamHelper.SaveStreamToFile(baseResponseStream, outFilePath, this, response.Content.Headers.ContentLength.GetValueOrDefault(), _cancelToken.Token);
             }
 
             if (!string.IsNullOrEmpty(StatusCodeVariable))

src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/Common/WebRequestPSCmdlet.Common.cs

@@ -484,6 +484,8 @@ namespace Microsoft.PowerShell.Commands
 
         internal string QualifiedOutFile => QualifyFilePath(OutFile);
 
+        internal string _qualifiedOutFile;
+
         internal bool ShouldCheckHttpStatus => !SkipHttpErrorCheck;
 
         /// <summary>
@@ -852,7 +854,7 @@ namespace Microsoft.PowerShell.Commands
             }
 
             // Output ??
-            if (PassThru && OutFile is null)
+            if (PassThru.IsPresent && OutFile is null)
             {
                 ErrorRecord error = GetValidationError(WebCmdletStrings.OutFileMissing, "WebCmdletOutFileMissingException", nameof(PassThru));
                 ThrowTerminatingError(error);
@@ -864,6 +866,15 @@ namespace Microsoft.PowerShell.Commands
                 ErrorRecord error = GetValidationError(WebCmdletStrings.OutFileMissing, "WebCmdletOutFileMissingException", nameof(Resume));
                 ThrowTerminatingError(error);
             }
+
+            _qualifiedOutFile = ShouldSaveToOutFile ? QualifiedOutFile : null;
+
+            // OutFile must not be a directory to use Resume.
+            if (Resume.IsPresent && Directory.Exists(_qualifiedOutFile))
+            {
+                ErrorRecord error = GetValidationError(WebCmdletStrings.ResumeNotFilePath, "WebCmdletResumeNotFilePathException", _qualifiedOutFile);
+                ThrowTerminatingError(error);
+            }
         }
 
         internal virtual void PrepareSession()
@@ -1093,6 +1104,7 @@ namespace Microsoft.PowerShell.Commands
             if (Resume.IsPresent)
             {
                 FileInfo fileInfo = new(QualifiedOutFile);
+
                 if (fileInfo.Exists)
                 {
                     request.Headers.Range = new RangeHeaderValue(fileInfo.Length, null);

src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/CoreCLR/InvokeWebRequestCommand.CoreClr.cs

@@ -56,7 +56,11 @@ namespace Microsoft.PowerShell.Commands
 
             if (ShouldSaveToOutFile)
             {
-                StreamHelper.SaveStreamToFile(responseStream, QualifiedOutFile, this, response.Content.Headers.ContentLength.GetValueOrDefault(), _cancelToken.Token);
+                string outFilePath = WebResponseHelper.GetOutFilePath(response, _qualifiedOutFile);
+
+                WriteVerbose(string.Create(System.Globalization.CultureInfo.InvariantCulture, $"File Name: {Path.GetFileName(_qualifiedOutFile)}"));
+
+                StreamHelper.SaveStreamToFile(responseStream, outFilePath, this, response.Content.Headers.ContentLength.GetValueOrDefault(), _cancelToken.Token);
             }
         }
 

src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/CoreCLR/WebResponseHelper.CoreClr.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Globalization;
+using System.IO;
 using System.Net.Http;
 
 namespace Microsoft.PowerShell.Commands
@@ -34,6 +35,14 @@ namespace Microsoft.PowerShell.Commands
             return headers;
         }
 
+        internal static string GetOutFilePath(HttpResponseMessage response, string _qualifiedOutFile)
+        {
+            // Get file name from last segment of Uri
+            string lastUriSegment = System.Net.WebUtility.UrlDecode(response.RequestMessage.RequestUri.Segments[^1]);
+
+            return Directory.Exists(_qualifiedOutFile) ? Path.Join(_qualifiedOutFile, lastUriSegment) : _qualifiedOutFile;
+        }
+
         internal static string GetProtocol(HttpResponseMessage response) => string.Create(CultureInfo.InvariantCulture, $"HTTP/{response.Version}");
 
         internal static int GetStatusCode(HttpResponseMessage response) => (int)response.StatusCode;

src/Microsoft.PowerShell.Commands.Utility/resources/WebCmdletStrings.resx

@@ -203,6 +203,9 @@
   </data>
   <data name="ReadResponseProgressStatus" xml:space="preserve">
     <value>Downloaded: {0} of {1}</value>
+  </data>
+   <data name="ResumeNotFilePath" xml:space="preserve">
+    <value>The Resume switch can only be used if OutFile targets a file but it resolves to a directory: {0}.</value>
   </data>
   <data name="SessionConflict" xml:space="preserve">
     <value>The cmdlet cannot run because the following conflicting parameters are specified: Session and SessionVariable. Specify either Session or SessionVariable, then retry.</value>

test/powershell/Modules/Microsoft.PowerShell.Utility/WebCmdlets.Tests.ps1

@@ -735,6 +735,19 @@ Describe "Invoke-WebRequest tests" -Tags "Feature", "RequireAdminOnWindows" {
         $jsonContent.headers.Host | Should -Be $uri.Authority
     }
 
+    It "Invoke-WebRequest -OutFile folder Downloads the file and names it" {
+        $uri = Get-WebListenerUrl -Test 'Get'
+        $content = Invoke-WebRequest -Uri $uri
+        $outFile = Join-Path $TestDrive $content.BaseResponse.RequestMessage.RequestUri.Segments[-1]
+
+        # ensure the file does not exist
+        Remove-Item -Force -ErrorAction Ignore -Path $outFile
+        Invoke-WebRequest -Uri $uri -OutFile $TestDrive
+
+        Test-Path $outFile | Should -Be $true
+        Get-Item $outFile | Select-Object -ExpandProperty Length | Should -Be $content.Content.Length
+    }
+
     It "Invoke-WebRequest should fail if -OutFile is <Name>." -TestCases @(
         @{ Name = "empty"; Value = [string]::Empty }
         @{ Name = "null"; Value = $null }
@@ -2000,6 +2013,11 @@ Describe "Invoke-WebRequest tests" -Tags "Feature", "RequireAdminOnWindows" {
                 Should -Throw -ErrorId 'WebCmdletOutFileMissingException,Microsoft.PowerShell.Commands.InvokeWebRequestCommand'
         }
 
+        It "Invoke-WebRequest -Resume should fail if -OutFile folder" {
+            { Invoke-WebRequest -Resume -Uri $resumeUri -OutFile $TestDrive -ErrorAction Stop } |
+                Should -Throw -ErrorId 'WebCmdletResumeNotFilePathException,Microsoft.PowerShell.Commands.InvokeWebRequestCommand'
+        }
+
         It "Invoke-WebRequest -Resume Downloads the whole file when the file does not exist" {
             $response = Invoke-WebRequest -Uri $resumeUri -OutFile $outFile -Resume -PassThru
 
@@ -2691,6 +2709,19 @@ Describe "Invoke-RestMethod tests" -Tags "Feature", "RequireAdminOnWindows" {
         $jsonContent.headers.Host | Should -Be $uri.Authority
     }
 
+    It "Invoke-RestMethod -OutFile folder Downloads the file and names it" {
+        $uri = Get-WebListenerUrl -Test 'Get'
+        $content = Invoke-WebRequest -Uri $uri
+        $outFile = Join-Path $TestDrive $content.BaseResponse.RequestMessage.RequestUri.Segments[-1]
+
+        # ensure the file does not exist
+        Remove-Item -Force -ErrorAction Ignore -Path $outFile
+        Invoke-RestMethod -Uri $uri -OutFile $TestDrive
+
+        Test-Path $outFile | Should -Be $true
+        Get-Item $outFile | Select-Object -ExpandProperty Length | Should -Be $content.Content.Length
+    }
+
     It "Invoke-RestMethod should fail if -OutFile is <Name>." -TestCases @(
         @{ Name = "empty"; Value = [string]::Empty }
         @{ Name = "null"; Value = $null }
@@ -3881,6 +3912,11 @@ Describe "Invoke-RestMethod tests" -Tags "Feature", "RequireAdminOnWindows" {
                 Should -Throw -ErrorId 'WebCmdletOutFileMissingException,Microsoft.PowerShell.Commands.InvokeRestMethodCommand'
         }
 
+        It "Invoke-RestMethod -Resume should fail if -OutFile folder" {
+            { Invoke-RestMethod -Resume -Uri $resumeUri -OutFile $TestDrive -ErrorAction Stop } |
+                Should -Throw -ErrorId 'WebCmdletResumeNotFilePathException,Microsoft.PowerShell.Commands.InvokeRestMethodCommand'
+        }
+
         It "Invoke-RestMethod -Resume Downloads the whole file when the file does not exist" {
             # ensure the file does not exist
             Remove-Item -Force -ErrorAction 'SilentlyContinue' -Path $outFile