2. Windows build - Use build script and full path

.github/workflows/build.yml

@@ -5,6 +5,8 @@ on: [push]
 env:
   DOTNET_CLI_TELEMETRY_OPTOUT: 1
   DOTNET_SKIP_FIRST_TIME_EXPERIENCE: 1
+  POWERSHELL_TELEMETRY_OPTOUT: 1
+  POWERSHELL_UPDATECHECK: Off
 
 jobs:
   windows:
@@ -24,6 +26,11 @@ jobs:
         with:
           fetch-depth: 0
 
+      - name: Verify Prebuild Script (Pester Tests)
+        shell: powershell
+        run: |
+          Invoke-Pester -Path "UI/tests/prebuild_windows.test.ps1" -Passthru | ForEach-Object { if ($_.FailedCount -gt 0) { exit 1 } }
+
       - name: Install .NET Core
         uses: actions/setup-dotnet@v4
         with:

COMPILING.md

@@ -1,9 +1,24 @@
 ## Windows
 
 1) Open the solution in Visual Studio 2022
+    * Mesen uses the "Desktop Development With C++" workload and the ".NET Desktop Development" workload
+    * You do **not** need to install them in advance. If you don't have them, Visual Studio will install them when you open the project.
 2) Compile as `Release`/`x64`
 3) Set the startup project to the `UI` project and run
 
+### Testing
+
+There is a [pester](https://pester.dev/) powershell test script in `UI/tests` that will verify the prebuild steps for the `UI` project.
+
+
+1. [Install pester](https://pester.dev/docs/introduction/installation) if needed.
+1. Run from any powershell console:
+
+```cmd
+$ .\UI\tests\prebuild_windows.test.ps1
+```
+
+
 ## Linux
 
 To build under Linux you need a version of Clang or GCC that supports C++17.  

UI/UI.csproj

@@ -650,7 +650,9 @@
   </ItemGroup>
 
   <Target Name="PreBuildWindows" BeforeTargets="PreBuildEvent" Condition="'$(RuntimeIdentifier)'=='win-x64'">
-    <Exec Command="cd $(OutDir)&#xD;&#xA;rd Dependencies /s /q&#xD;&#xA;md Dependencies&#xD;&#xA;xcopy /s $(ProjectDir)Dependencies\* Dependencies&#xD;&#xA;copy libHarfBuzzSharp.dll Dependencies&#xD;&#xA;copy libSkiaSharp.dll Dependencies&#xD;&#xA;copy MesenCore.dll Dependencies&#xD;&#xA;cd Dependencies&#xD;&#xA;del ..\Dependencies.zip&#xD;&#xA;powershell Compress-Archive -Path * -DestinationPath '..\Dependencies.zip' -Force&#xD;&#xA;copy ..\Dependencies.zip $(ProjectDir)" />
+    <Exec 
+    Command="powershell -ExecutionPolicy Bypass -File &quot;$(ProjectDir)prebuild_windows.ps1&quot; -OutDir &quot;$(ProjectDir)..\bin\$(RuntimeIdentifier)\$(Configuration)&quot; -ProjectDir &quot;$(ProjectDir.TrimEnd('\'))&quot; -RuntimeIdentifier &quot;$(RuntimeIdentifier)&quot;" 
+    WorkingDirectory="$(ProjectDir)" />
   </Target>
 
 	<Target Name="PreBuildLinux" BeforeTargets="PreBuildEvent" Condition="'$(RuntimeIdentifier)'=='linux-x64' Or '$(RuntimeIdentifier)'=='linux-arm64'">

UI/prebuild_windows.ps1

@@ -0,0 +1,128 @@
+# find and copy the files needed for building the UI project.
+# called by the build target in UI.csproj.
+# these steps are stored as a script for easier reading and editing.
+
+param (
+    [string]$OutDir,           # $(ProjectDir)..\bin\$(RuntimeIdentifier)\$(Configuration), like bin\win-x64\Release
+    [string]$ProjectDir,
+    [string]$RuntimeIdentifier # win-x64, win-arm64, etc.
+)
+
+$ErrorActionPreference = "Stop"
+
+try {
+
+    $MissingParams = foreach ($Name in "ProjectDir", "OutDir", "RuntimeIdentifier") {
+        if ([string]::IsNullOrWhiteSpace((Get-Variable $Name -ValueOnly))) {
+            $Name
+        }
+    }
+
+    if ($MissingParams) {
+        $List = $MissingParams -join ", "
+        throw [System.ArgumentException] "Required parameter(s) '[$List]' are missing or empty."
+    }
+
+    # clean paths (PowerShell handles trailing slashes/dots automatically with Get-Item)
+    $ProjectDir = $ProjectDir.TrimEnd('\')
+    if ($OutDir -match '^[a-zA-Z]:') {
+        $FullOutDir = $OutDir
+    } else {
+        $FullOutDir = Join-Path "$ProjectDir" $OutDir
+    }
+
+    Write-Host "[PREBUILD] Project Dir: $ProjectDir"
+    Write-Host "[PREBUILD] Target Dir : $FullOutDir"
+
+    # ensure FullOutDir exists and move there
+    if (!(Test-Path $FullOutDir)) { New-Item -ItemType Directory -Path $FullOutDir | Out-Null }
+    if (!(Test-Path $FullOutDir)) {
+        throw [System.IO.DirectoryNotFoundException] "$FullOutDir does not exist"
+    }
+    Set-Location $FullOutDir
+
+    # set up Dependencies folder
+    $DepsFolder = Join-Path $FullOutDir "Dependencies"
+    if (Test-Path $DepsFolder) { Remove-Item -Recurse -Force $DepsFolder }
+    New-Item -ItemType Directory -Path $DepsFolder | Out-Null
+
+    # 1. copy external dlls managed by NuGet package manager.
+    # in web CI builds these are installed by 'dotnet restore'.
+    $Libs = @("libHarfBuzzSharp.dll", "libSkiaSharp.dll")
+    $NuGetBase = "$env:USERPROFILE\.nuget\packages"
+    $SpecificPathPart = "runtimes\$RuntimeIdentifier\native"
+
+    foreach ($Lib in $Libs) {
+        $FoundFile = Get-ChildItem -Path $NuGetBase -Filter $Lib -Recurse | 
+                 Where-Object { $_.FullName -like "*$SpecificPathPart*" } | 
+                 Select-Object -First 1
+
+    if ($FoundFile -and (Test-Path $FoundFile.FullName)) {
+        $LibSourcePath = $FoundFile.FullName
+        Write-Host "[PREBUILD] Copying NuGet dll $LibSourcePath"
+        Copy-Item $LibSourcePath -Destination $DepsFolder
+    } else {
+            $troubleshooting = "Please rebuild or restore packages. (Right-click solution in Visual Studio -> click 'Restore NuGet Packages', or run 'dotnet restore' in shell"
+
+            $SearchPattern = Join-Path $NuGetBase "*\$SpecificPathPart"
+            $DllSourceFolder = $ExecutionContext.SessionState.Path.GetUnresolvedProviderPathFromPSPath($SearchPattern)
+
+            throw [System.IO.FileNotFoundException] "Required file '$Lib' for $RuntimeIdentifier not found in '$DllSourceFolder'. $troubleshooting"
+        }
+    }
+
+    # 2. copy MesenCore.dll output from building the Core c++ project
+    $Dll = "MesenCore.dll"
+    $DllSourcePath = Join-Path $FullOutDir $Dll
+
+    if (!(Test-Path $DllSourcePath)) {
+        Write-Host "[PREBUILD] $Dll not found in $DllSourcePath . Checking fallback path"
+        # Fallback: Check if the file is one level up or if the OutDir had a double-slash issue
+        $ParentDir = Split-Path $FullOutDir -Parent
+        $FoundFile = Get-ChildItem -Path $ParentDir -Filter $Dll -Recurse | Select-Object -First 1
+
+        if ($FoundFile) {
+            $DllSourcePath = $FoundFile.FullName
+        }
+    }
+
+    if ($DllSourcePath -and (Test-Path $DllSourcePath)) {
+        Write-Host "[PREBUILD] Copying $Dll from: $DllSourcePath"
+        Copy-Item $DllSourcePath -Destination $DepsFolder
+    } else {
+        $ParentPath = Split-Path $DllSourcePath -Parent
+        $DllSourceFolder = $ExecutionContext.SessionState.Path.GetUnresolvedProviderPathFromPSPath($ParentPath)
+        throw [System.IO.FileNotFoundException] "Required file '$Dll' not found in '$DllSourceFolder'. Please try rebuilding the solution."
+    }
+
+    # 3. copy files that exist in source control
+    Write-Host "[PREBUILD] Copying other dependencies from $ProjectDir\Dependencies"
+    Copy-Item -Path "$ProjectDir\Dependencies\*" -Destination $DepsFolder -Recurse -Force
+
+    # zip files
+    $ZipPath = Join-Path $FullOutDir "Dependencies.zip"
+    if (Test-Path $ZipPath) { Remove-Item $ZipPath }
+
+    Write-Host "[PREBUILD] Creating Zip $ZipPath..."
+    Compress-Archive -Path $DepsFolder -DestinationPath $ZipPath -Force
+
+    # move instead of copy so we don't leave copies of the zip lying around
+    Move-Item $ZipPath -Destination (Join-Path $ProjectDir "Dependencies.zip") -Force
+    Write-Host "[PREBUILD] Success."
+}
+catch {
+
+    # format an error message that shows the error inside Visual Studio.
+    # using this specific format turns this into a clickable link in the Error List window or tab.
+    # Format: path\to\file.ps1(line): error: message
+    # https://learn.microsoft.com/en-us/visualstudio/msbuild/msbuild-diagnostic-format-for-tasks
+
+    $file = $_.InvocationInfo.ScriptName
+    $line = $_.InvocationInfo.ScriptLineNumber
+    $errorMessage = "$file($line): error: $($_.Exception.Message)"
+
+    # write to regular output so Visual Studio picks up + parses the message
+    Write-Host $errorMessage
+
+    exit 1
+}

UI/tests/prebuild_windows.test.ps1

@@ -0,0 +1,158 @@
+# test that all needed scenarios of the prebuild_windows script work.
+
+Describe "Mesen Prebuild Logic Verification" {
+    BeforeAll {
+        # set up sandbox in Temp
+        $Sandbox = Join-Path $env:TEMP "Mesen_CI_Sandbox"
+        if (Test-Path $Sandbox) { Remove-Item $Sandbox -Recurse -Force -ErrorAction SilentlyContinue }
+        New-Item -Path $Sandbox -ItemType Directory -Force | Out-Null
+
+        # map T: to this sandbox so Join-Path ..\.. works correctly
+        if (Get-PSDrive T -ErrorAction SilentlyContinue) { Remove-PSDrive T }
+        New-PSDrive -Name T -PSProvider FileSystem -Root $Sandbox | Out-Null
+
+        $script:OldProfile = $env:USERPROFILE
+        $env:USERPROFILE = "T:\Users\testuser"
+
+        $PREBUILD_SCRIPT = "$PSScriptRoot/../prebuild_windows.ps1"
+        $RUNTIME_ID = "win-x64"
+
+        $script:TestNumber = 0
+    }
+
+    AfterAll {
+        $env:USERPROFILE = $script:OldProfile
+        if (Get-PSDrive T -ErrorAction SilentlyContinue) { Remove-PSDrive T }
+    }
+
+    Context "Full Mock Isolation" {
+        BeforeEach {
+            # mock all actions that might cause changes on disk
+            Mock Compress-Archive { }
+            Mock Copy-Item { }
+            Mock Get-Item { param($Path) return [PSCustomObject]@{ FullName = $Path } }
+            Mock Move-Item { }
+            Mock New-Item { return [PSCustomObject]@{ FullName = "MockedDir" } }
+            Mock Remove-Item { }
+            Mock Set-Location { }
+            Mock Test-Path { return $true }
+
+            Mock Get-ChildItem {
+                param($Path, $Filter)
+                if ($Path -like "*\.nuget\*") {
+                    return [PSCustomObject]@{ FullName = Join-Path $env:USERPROFILE ".nuget\packages\runtimes\$RUNTIME_ID\native\$Filter" }
+                }
+                if ($Filter -eq "MesenCore.dll") {
+                    return [PSCustomObject]@{ FullName = Join-Path $env:USERPROFILE "code\mesen\bin\$RUNTIME_ID\Release\MesenCore.dll" }
+                }
+            }
+            $error.Clear()
+
+            $script:TestNumber += 1
+            Write-Host "-------"
+            Write-Host "[Test] $TestNumber" -ForegroundColor Cyan
+        }
+
+        It "Should handle Relative OutDir (Local Style)" {
+            $params = @{
+                ProjectDir = Join-Path $env:USERPROFILE "code\UI"
+                OutDir     = "..\bin\Release"
+                RuntimeIdentifier = $RUNTIME_ID
+            }
+            { & $PREBUILD_SCRIPT @params } | Should -Not -Throw
+        }
+
+        It "Should handle Absolute OutDir (CI Style)" {
+            $params = @{
+                ProjectDir = Join-Path $env:USERPROFILE "code\UI"
+                OutDir     = Join-Path $env:USERPROFILE "code\bin\Release"
+                RuntimeIdentifier = $RUNTIME_ID
+            }
+            { & $PREBUILD_SCRIPT @params } | Should -Not -Throw
+        }
+
+        It "Matches the vcxproj OutDir structure" {
+            $Repo = "T:\MesenRepo"
+            $ProjectDir = "$Repo\UI"
+
+            Mock Test-Path { return $true }
+            Mock Copy-Item { }
+            Mock Compress-Archive { }
+            Mock Move-Item { }
+            Mock New-Item { [PSCustomObject]@{ FullName = "MockedDir" } }
+            Mock Set-Location { }
+
+            $params = @{
+                ProjectDir        = $ProjectDir
+                OutDir            = "..\bin\$RUNTIME_ID\Release"
+                RuntimeIdentifier = $RUNTIME_ID
+            }
+
+            { & $PREBUILD_SCRIPT @params } | Should -Not -Throw
+        }
+
+        It "Should verify the zip ends up in the ProjectDir" {
+            $ProjectDir = Join-Path $env:USERPROFILE "code\mesen\UI"
+
+            $params = @{
+                ProjectDir = $ProjectDir
+                OutDir     = "T:\Some\Other\Path"
+                RuntimeIdentifier = $RUNTIME_ID
+            }
+            { & $PREBUILD_SCRIPT @params } | Should -Not -Throw
+
+            $ExpectedDestination = Join-Path $ProjectDir "Dependencies.zip"
+
+            Assert-MockCalled Move-Item -ParameterFilter { 
+                $Destination -eq $ExpectedDestination
+            }
+        }
+
+        It "Should raise exception on empty paths" {
+            $params = @{ ProjectDir = ""; OutDir = ""; RuntimeIdentifier = "win-x64" }
+
+            & $PREBUILD_SCRIPT @params 2>&1
+
+            $error.Count | Should -BeGreaterThan 0
+            $error[0].Exception.GetType().FullName | Should -Be "System.ArgumentException"
+            $LASTEXITCODE | Should -Be 1
+        }
+
+        It "Should raise exception when NuGet DLL is missing" {
+            Mock Get-ChildItem { return $null } -ParameterFilter { $Path -like "*\.nuget\*" }
+
+            $params = @{
+                ProjectDir = "T:\Mesen"
+                OutDir     = "bin"
+                RuntimeIdentifier = $RUNTIME_ID
+            }
+
+            & $PREBUILD_SCRIPT @params 2>&1
+
+            $error.Count | Should -BeGreaterThan 0
+            $error[0].Exception.GetType().FullName | Should -Be "System.IO.FileNotFoundException"
+            $LASTEXITCODE | Should -Be 1
+        }
+
+        It "Should print error when MesenCore.dll is missing" {
+            Mock Test-Path { 
+                param($Path) 
+                if ($Path -like "*MesenCore.dll") { return $false }
+                return $true 
+            }
+            Mock Get-ChildItem { return $null } -ParameterFilter { $Filter -eq "MesenCore.dll" }
+
+            $params = @{
+                ProjectDir = "T:\Mesen"
+                OutDir     = "bin"
+                RuntimeIdentifier = $RUNTIME_ID
+            }
+
+            & $PREBUILD_SCRIPT @params 2>&1
+
+            $error.Count | Should -BeGreaterThan 0
+            $error[0].Exception.GetType().FullName | Should -Be "System.IO.FileNotFoundException"
+            $LASTEXITCODE | Should -Be 1
+        }
+    }
+}