Check if the command is present before attempting to call WinGet

doc/ReleaseNotes.md

@@ -1,3 +1,6 @@
 ## New in v1.28
 
 <!-- Nothing yet! -->
+
+## Bug Fixes
+* The PowerShell module now checks for the executable to be in the path before calling it when using `Repair-WinGetPackageManager`

src/PowerShell/Microsoft.WinGet.Client.Engine/Common/WinGetIntegrity.cs

@@ -7,8 +7,10 @@
 namespace Microsoft.WinGet.Client.Engine.Common
 {
     using System;
+    using System.Collections.ObjectModel;
     using System.ComponentModel;
     using System.IO;
+    using System.Linq;
     using System.Management.Automation;
     using Microsoft.WinGet.Client.Engine.Exceptions;
     using Microsoft.WinGet.Client.Engine.Helpers;
@@ -39,29 +41,55 @@ public static void AssertWinGet(PowerShellCmdlet pwshCmdlet, string expectedVers
                 return;
             }
 
-            try
-            {
-                // Start by calling winget without its WindowsApp PFN path.
-                // If it succeeds and the exit code is 0 then we are good.
-                var wingetCliWrapper = new WingetCLIWrapper(false);
-                var result = wingetCliWrapper.RunCommand(pwshCmdlet, "--version");
-                result.VerifyExitCode();
-            }
-            catch (Win32Exception e)
-            {
-                pwshCmdlet.Write(StreamType.Verbose, $"'winget.exe' Win32Exception {e.Message}");
-                throw new WinGetIntegrityException(GetReason(pwshCmdlet));
-            }
-            catch (Exception e) when (e is WinGetCLIException || e is WinGetCLITimeoutException)
-            {
-                pwshCmdlet.Write(StreamType.Verbose, $"'winget.exe' WinGetCLIException {e.Message}");
-                throw new WinGetIntegrityException(IntegrityCategory.Failure, e);
-            }
-            catch (Exception e)
+            pwshCmdlet.ExecuteInPowerShellThread(() =>
             {
-                pwshCmdlet.Write(StreamType.Verbose, $"'winget.exe' Exception {e.Message}");
-                throw new WinGetIntegrityException(IntegrityCategory.Unknown, e);
-            }
+                try
+                {
+                    // First check if winget is registered in the current session using Get-Command.
+                    var ps = PowerShell.Create(RunspaceMode.CurrentRunspace);
+                    {
+                        // Ignore the error, we will check the results instead
+                        ps.AddCommand("Get-Command").AddParameter("Name", "winget").AddParameter("ErrorAction", "Ignore");
+                        Collection<PSObject> results = ps.Invoke();
+                        ps.Dispose();
+                        if (results == null ||
+                            results.Count != 1 ||
+                            results.ElementAt(0).BaseObject is not CommandInfo)
+                        {
+                            // It's expected that the command is found, is the only command, and is a CommandInfo object.
+                            // If it is not, then winget is not properly registered in the current session and we need to figure out why.
+                            pwshCmdlet.Write(StreamType.Verbose, $"'winget' was not found using Get-Command");
+                            throw new WinGetIntegrityException(GetReason(pwshCmdlet, false));
+                        }
+                    }
+
+                    // If the command is registered, try calling winget without its WindowsApp PFN path.
+                    // If it succeeds and the exit code is 0 then we are good.
+                    var wingetCliWrapper = new WingetCLIWrapper(false);
+                    var result = wingetCliWrapper.RunCommand(pwshCmdlet, "--version");
+                    result.VerifyExitCode();
+                }
+                catch (WinGetIntegrityException)
+                {
+                    // We already know the reason why it failed. Just rethrow, but be sure to preserve the stack trace
+                    throw;
+                }
+                catch (Win32Exception e)
+                {
+                    pwshCmdlet.Write(StreamType.Verbose, $"'winget.exe' Win32Exception {e.Message}");
+                    throw new WinGetIntegrityException(GetReason(pwshCmdlet, true));
+                }
+                catch (Exception e) when (e is WinGetCLIException || e is WinGetCLITimeoutException)
+                {
+                    pwshCmdlet.Write(StreamType.Verbose, $"'winget.exe' WinGetCLIException {e.Message}");
+                    throw new WinGetIntegrityException(IntegrityCategory.Failure, e);
+                }
+                catch (Exception e)
+                {
+                    pwshCmdlet.Write(StreamType.Verbose, $"'winget.exe' Exception {e.Message}");
+                    throw new WinGetIntegrityException(IntegrityCategory.Unknown, e);
+                }
+            });
 
             // WinGet is installed. Verify version if needed.
             if (!string.IsNullOrEmpty(expectedVersion))
@@ -81,31 +109,39 @@ public static void AssertWinGet(PowerShellCmdlet pwshCmdlet, string expectedVers
             }
         }
 
-        private static IntegrityCategory GetReason(PowerShellCmdlet pwshCmdlet)
+        private static IntegrityCategory GetReason(PowerShellCmdlet pwshCmdlet, bool commandIsRegistered)
         {
             // Ok, so you are here because calling winget --version failed. Lets try to figure out why.
             var category = IntegrityCategory.Unknown;
-            pwshCmdlet.ExecuteInPowerShellThread(() =>
+
+            // If the command is registered, then we can try to call it
+            // Otherwise we will skip this step since it will always result in category remaining unknown
+            if (commandIsRegistered)
             {
+                pwshCmdlet.ExecuteInPowerShellThread(() =>
+                {
                 // When running winget.exe on PowerShell the message of the Win32Exception will distinguish between
                 // 'The system cannot find the file specified' and 'No applicable app licenses found' but of course
                 // the HRESULT is the same (E_FAIL).
                 // To not compare strings let Powershell handle it. If calling winget throws an
                 // ApplicationFailedException then is most likely that the license is not there.
-                try
-                {
-                    var ps = PowerShell.Create(RunspaceMode.CurrentRunspace);
-                    ps.AddCommand("winget").Invoke();
-                }
-                catch (ApplicationFailedException e)
-                {
-                    pwshCmdlet.Write(StreamType.Verbose, e.Message);
-                    category = IntegrityCategory.AppInstallerNoLicense;
-                }
-                catch (Exception)
-                {
-                }
-            });
+                    try
+                    {
+                        using (var ps = PowerShell.Create(RunspaceMode.CurrentRunspace))
+                        {
+                            ps.AddCommand("winget").Invoke();
+                        }
+                    }
+                    catch (ApplicationFailedException e)
+                    {
+                        pwshCmdlet.Write(StreamType.Verbose, e.Message);
+                        category = IntegrityCategory.AppInstallerNoLicense;
+                    }
+                    catch (Exception)
+                    {
+                    }
+                });
+            }
 
             if (category != IntegrityCategory.Unknown)
             {