Add .build.ps1 logic to automatically download dotnet cli if missing

Author: daviwil

.build.ps1

@@ -5,17 +5,56 @@ param(
 
 #Requires -Modules @{ModuleName="InvokeBuild";ModuleVersion="3.2.1"}
 
-task EnsureDotNet -Before Clean, Build, BuildHost, Test, TestPowerShellApi {
-    # TODO: Download if it doesn't exist in known paths
-    if (!(Test-Path 'c:\Program Files\dotnet\dotnet.exe')) {
-        Write-Error "dotnet is not installed"
+task SetupDotNet -Before Clean, Build, BuildHost, Test, TestPowerShellApi {
+
+    # Bail out early if we've already found the exe path
+    if ($script:dotnetExe -ne $null) { return }
+
+    $requiredDotnetVersion = "1.0.0-preview4-004233"
+    $needsInstall = $true
+    $dotnetPath = "$PSScriptRoot/.dotnet"
+    $dotnetExePath = "$dotnetPath/dotnet.exe"
+
+    if (Test-Path $dotnetExePath) {
+        $script:dotnetExe = $dotnetExePath
     }
+    else {
+        $installedDotnet = Get-Command dotnet -ErrorAction Ignore
+        if ($installedDotnet) {
+            $dotnetExePath = $installedDotnet.Source
 
-    exec {
-        if (!((& dotnet --version) -like "*preview4*")) {
-            Write-Error "You must have at least preview4 of the dotnet tools installed."
+            exec {
+                if ((& $dotnetExePath --version) -eq $requiredDotnetVersion) {
+                    $script:dotnetExe = $dotnetExePath
+                }
+            }
+        }
+
+        if ($script:dotnetExe -eq $null) {
+
+            Write-Host "`n### Installing .NET CLI $requiredDotnetVersion...`n" -ForegroundColor Green
+
+            # Download the official installation script and run it
+            $installScriptPath = "$($env:TEMP)\dotnet-install.ps1"
+            Invoke-WebRequest "https://raw.githubusercontent.com/dotnet/cli/rel/1.0.0-preview4/scripts/obtain/dotnet-install.ps1" -OutFile $installScriptPath
+            $env:DOTNET_INSTALL_DIR = "$PSScriptRoot\.dotnet"
+            & $installScriptPath -Version $requiredDotnetVersion -InstallDir "$env:DOTNET_INSTALL_DIR"
+
+            Write-Host "`n### Installation complete." -ForegroundColor Green
+            $script:dotnetExe = $dotnetExePath
         }
     }
+
+    # This variable is used internally by 'dotnet' to know where it's installed
+    $script:dotnetExe = Resolve-Path $script:dotnetExe
+    if (!$env:DOTNET_INSTALL_DIR)
+    {
+        $dotnetExeDir = [System.IO.Path]::GetDirectoryName($script:dotnetExe)
+        $env:PATH = $dotnetExeDir + [System.IO.Path]::PathSeparator + $env:PATH
+        $env:DOTNET_INSTALL_DIR = $dotnetExeDir
+    }
+
+    Write-Host "`n### Using dotnet at path $script:dotnetExe`n" -ForegroundColor Green
 }
 
 task Clean {
@@ -36,7 +75,7 @@ task TestPowerShellApi {
     BuildForPowerShellVersion v5r2
 }
 
-task BuildHost EnsureDotNet, {
+task BuildHost {
     # This task is meant to be used in a quick dev cycle so no 'restore' is done first
     exec { & dotnet build -c $Configuration .\src\PowerShellEditorServices.Host\PowerShellEditorServices.Host.csproj }
 }

.gitignore

@@ -26,6 +26,7 @@ lock
 .corext/gen
 registered_data.ini
 .vs/
+.dotnet/
 module/
 
 docs/_site/

.nuget/NuGet.Config

@@ -3,4 +3,10 @@
   <solution>
     <add key="disableSourceControlIntegration" value="true" />
   </solution>
+  <packageSources>
+    <clear />
+    <add key="CI Builds (dotnet-core)" value="https://www.myget.org/F/dotnet-core/api/v3/index.json" />
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
+    <add key="powershell-core" value="https://powershell.myget.org/F/powershell-core/api/v3/index.json" />
+  </packageSources>
 </configuration>

.vscode/settings.json

@@ -0,0 +1,4 @@
+// Place your settings in this file to overwrite default and user settings.
+{
+    "files.trimTrailingWhitespace": true
+}