Implement Support for One-liner Installs (#1957)

* Download Zip File as a Fallback in Install-IronPython.ps1

* Add Default Path to Install-IronPython.ps1

* Add iex DownloadString Invocation Example to Install-IronPython.ps1

* Add Install-IronPython.ps1 to README.md

* Fix Destination Path Install-IronPython.ps1

* Add PowerShell Usage Examples to README.md

* Catch API Errors in Install-IronPython.ps1

* Use `Scriptblock.Create` Instead of `iex` in PowerShell Example in README.md

* Reverse $Path to Have no Default Value in Install-IronPython.ps1

Also fixes example text

* Fix Search Paths in README PowerShell Example

* Fix the One-Liner in the README

* Improve Verbage in PowerShell Example in README.md

* Make Download Path in Install-IronPython.ps1 Cross-Platform

* Fix Example in Install-IronPython.ps1

* Use Different Install Path in README.md PowerShell Example

* Improve PowerShell Example in README.md by Adding Pip, SQLite, and WPF

* Use Different Example Install Path in Install-IronPython.ps1 Usage Text

* Fix Search Paths in README.md PowerShell Example

bumping to 3.4.2 will occur in a later commit

* Fix and Improve Search Path Resolution in README.md PowerShell Example

* Bump 3.4.0 to 3.4.2 in README.md

* Add Link for PowerShell Usage in README.md

* Improve Readability of One-Liner in README.md

* Bump 3.4.0 to 3.4.2 in Install-IronPython.ps1

Also places web install into its own example block

Author: anonhostpi

README.md

@@ -12,12 +12,14 @@ IronPython 3 targets Python 3, including the re-organized standard library, Unic
 | **What?** | **Where?** |
 | --------: | :------------: |
 | **Windows/Linux/macOS Builds** | [![Build status](https://dotnet.visualstudio.com/IronLanguages/_apis/build/status/ironpython3)](https://dotnet.visualstudio.com/IronLanguages/_build/latest?definitionId=43) [![Github build status](https://github.com/IronLanguages/ironpython3/workflows/CI/badge.svg)](https://github.com/IronLanguages/ironpython3/actions?workflow=CI) |
-| **Downloads** | [![NuGet](https://img.shields.io/nuget/vpre/IronPython.svg)](https://www.nuget.org/packages/IronPython/3.4.0) [![Release](https://img.shields.io/github/release/IronLanguages/ironpython3.svg?include_prereleases)](https://github.com/IronLanguages/ironpython3/releases/latest)|
+| **Downloads** | [![NuGet](https://img.shields.io/nuget/vpre/IronPython.svg)](https://www.nuget.org/packages/IronPython/3.4.2) [![Release](https://img.shields.io/github/release/IronLanguages/ironpython3.svg?include_prereleases)](https://github.com/IronLanguages/ironpython3/releases/latest)|
 | **Help** | [![Gitter chat](https://badges.gitter.im/IronLanguages/ironpython.svg)](https://gitter.im/IronLanguages/ironpython) [![StackExchange](https://img.shields.io/badge/stack%20overflow-ironpython-informational?logo=stack-overflow&logoColor=white)](https://stackoverflow.com/questions/tagged/ironpython) |
 
 
 ## Examples
 
+To see how to use in PowerShell (either directly embedded or executable invocation), skip to [Installation](#Installation)
+
 The following C# program:
 
 ```cs
@@ -87,7 +89,62 @@ See the [Package compatibility](https://github.com/IronLanguages/ironpython3/wik
 
 ## Installation
 
-Binaries of IronPython 3 can be downloaded from the [release page](https://github.com/IronLanguages/ironpython3/releases/latest), available in various formats: `.msi`, `.zip`, `.deb`, `.pkg`. The IronPython package is also available on [NuGet](https://www.nuget.org/packages/IronPython/3.4.0). See the [installation document](https://github.com/IronLanguages/ironpython3/wiki/Installing) for detailed instructions on how to install a standalone IronPython interpreter on various operating systems and .NET frameworks.
+Binaries of IronPython 3 can be downloaded from the [release page](https://github.com/IronLanguages/ironpython3/releases/latest), available in various formats: `.msi`, `.zip`, `.deb`, `.pkg`. The IronPython package is also available on [NuGet](https://www.nuget.org/packages/IronPython/3.4.2). See the [installation document](https://github.com/IronLanguages/ironpython3/wiki/Installing) for detailed instructions on how to install a standalone IronPython interpreter on various operating systems and .NET frameworks.
+
+### PowerShell
+
+For usage in PowerShell, you can install using the Install-IronPython.ps1 within the aforementioned `.zip` file or by simply using this one-liner:
+
+```pwsh
+& ([scriptblock]::Create((iwr `
+    -Uri 'https://raw.githubusercontent.com/IronLanguages/ironpython3/main/eng/scripts/Install-IronPython.ps1').Content)) `
+    -Path "~/ipyenv/v3.4.2"
+
+# Optionally, ensure pip:
+# & "~/ipyenv/v3.4.2/ipy" -m ensurepip
+```
+
+Once installed, you can start using IronPython directly in PowerShell!
+
+To use the ipy shim, you can use:
+```pwsh
+& "~/ipyenv/v3.4.2/Enter-IronPythonEnvironment.ps1"
+
+ipy -c "print('Hello from IronPython!')"
+```
+
+... or to use IronPython embedded in PowerShell, you can use:
+```pwsh
+Import-Module "~/ipyenv/v3.4.2/IronPython.dll"
+
+$engine = & {
+    $engine = [IronPython.Hosting.Python]::CreateEngine()
+
+    # You need to add the correct paths, as IronPython will use PowerShell's installation path by default
+    $paths = $engine.GetSearchPaths()
+    $paths.Add("$(Resolve-Path "~/ipyenv/v3.4.2/lib")")
+    $paths.Add("$(Resolve-Path "~/ipyenv/v3.4.2/lib/site-packages")")
+
+    # To use `wpf` and `sqlite3` you have to add the DLLs search path
+    # - the [IronPython.SQLite] and [IronPython.WPF] powershell namespaces will become available on python import
+    $paths.Add("$(Resolve-Path "~/ipyenv/v3.4.2/DLLs")")
+
+    # or if you prefer to have the powershell namespaces early, you can use:
+    # - just note, you will have to initialize _sqlite3 (see further down the script)
+    # Import-Module "~/ipyenv/v3.4.2/DLLs/IronPython.SQLite.dll"
+    # Import-Module "~/ipyenv/v3.4.2/DLLs/IronPython.WPF.dll"
+
+    $engine.SetSearchPaths($paths)
+
+    # Then have fun!
+    $engine.Execute("print('Hello from IronPython!')")
+
+    # Optionally, if you need to initialize _sqlite3:
+    # $engine.Execute("import sqlite3")
+
+    return $engine
+}
+```
 
 ## Build
 

eng/scripts/Install-IronPython.ps1

@@ -12,18 +12,26 @@
 
 .EXAMPLE
 
-    PS>Invoke-WebRequest -Uri https://github.com/IronLanguages/ironpython3/releases/download/v3.4.0/IronPython.3.4.0.zip -OutFile IronPython.3.4.0.zip
-    PS>Expand-Archive -Path IronPython.3.4.0.zip -DestinationPath IronPython-unzipped
-    PS>./IronPython-unzipped/scripts/Install-IronPython -Path ~/ipyenv/v3.4.0
+    With a one-liner, install latest over the web:
 
-    The official binaries are downloaded from GitHub to the current directory, unzipped, and then the installation proceeds using the script from the unzipped directory. IronPython is installed into ~/ipyenv/v3.4.0.
+    PS>& ([scriptblock]::Create((iwr 'https://raw.githubusercontent.com/IronLanguages/ironpython3/main/eng/scripts/Install-IronPython.ps1').Content)) -Path ~/ipyenv/v3.4.2
+
+    The official binaries are downloaded from GitHub to the current directory, unzipped, and then the installation proceeds using the script from the unzipped directory. IronPython is installed into ~/ipyenv/v3.4.2
+
+.EXAMPLE
+
+    PS>Invoke-WebRequest -Uri https://github.com/IronLanguages/ironpython3/releases/download/v3.4.2/IronPython.3.4.2.zip -OutFile IronPython.3.4.2.zip
+    PS>Expand-Archive -Path IronPython.3.4.2.zip -DestinationPath IronPython-unzipped
+    PS>./IronPython-unzipped/scripts/Install-IronPython -Path ~/ipyenv/v3.4.2
+
+    The official binaries are downloaded from GitHub to the current directory, unzipped, and then the installation proceeds using the script from the unzipped directory. IronPython is installed into ~/ipyenv/v3.4.2
 
 .EXAMPLE
 
-    PS>Invoke-WebRequest -Uri https://github.com/IronLanguages/ironpython3/releases/download/v3.4.0/IronPython.3.4.0.zip -OutFile IronPython.3.4.0.zip
-    PS>Install-IronPython -Path ~/ipyenv/v3.4.0 -ZipFile IronPython.3.4.0.zip -Framework net462 -Force
+    PS>Invoke-WebRequest -Uri https://github.com/IronLanguages/ironpython3/releases/download/v3.4.2/IronPython.3.4.2.zip -OutFile IronPython.3.4.2.zip
+    PS>Install-IronPython -Path ~/ipyenv/v3.4.2 -ZipFile IronPython.3.4.2.zip -Framework net462 -Force
 
-    The official binaries are downloaded from GitHub to the current directory and then the installation proceeds using the downloaded zip file. IronPython is installed into ~/ipyenv/v3.4.0, overwriting any previous installation in that location. IronPython binaries running on .NET Framework 4.6.2 are used during the installation.
+    The official binaries are downloaded from GitHub to the current directory and then the installation proceeds using the downloaded zip file. IronPython is installed into ~/ipyenv/v3.4.2, overwriting any previous installation in that location. IronPython binaries running on .NET Framework 4.6.2 are used during the installation.
     This example assumes that the installation script is in a directory on the search path ($env:PATH).
 
 .EXAMPLE
@@ -54,6 +62,8 @@ Param(
 
 $ErrorActionPreference = "Stop"
 
+$downloaded = $false
+
 if (-not $ZipFile) {
     # If zipfile path not given, try to locate it
     $splitPSScriptRoot = $PSScriptRoot -split "\$([IO.Path]::DirectorySeparatorChar)"
@@ -72,7 +82,23 @@ if (-not $ZipFile) {
         }
         $ZipFile = $zipFiles
     } else {
-        Write-Error "Cannot locate implicit zip file. Provide path to the zip file using '-ZipFile <path>'."
+        Try {
+            $zipUrl = (Invoke-RestMethod "https://api.github.com/repos/IronLanguages/ironpython3/releases/latest").assets |
+                Where-Object -Property name -Like "IronPython.3.*.zip" | 
+                Select-Object -ExpandProperty browser_download_url
+        
+            $downloadPath = "$([System.IO.Path]::GetTempPath())$([guid]::NewGuid()).zip"
+            Invoke-WebRequest -Uri $zipUrl -OutFile $downloadPath | Out-Null
+            
+            if (-not (Test-Path -PathType Leaf $downloadPath)) {
+                throw
+            }
+            
+            $downloaded = $true
+            $ZipFile = $downloadPath
+        } Catch {
+            Write-Error "Cannot retrieve zip file implicitly. Check your network connection or provide a path to the zip file using '-ZipFile <path>'."
+        }
     }
 } elseif (-not (Test-Path $ZipFile)) {
     Write-Error "ZipFile not found: $ZipFile"
@@ -85,16 +111,24 @@ if (Test-Path $Path) {
             Write-Error "Overwriting of multiple destinations not allowed: $Path"
         }
         Remove-Item -Path $Path -Force -Recurse
+        New-Item $Path -ItemType Directory | Out-Null
     } else {
-        Write-Error "Path already exists: $Path"
+        Write-Warning "Path already exists: $(Resolve-Path $Path)"
     }
+} else {
+    New-Item $Path -ItemType Directory | Out-Null
 }
-New-Item $Path -ItemType Directory | Out-Null
 
 # Unzip archive
 if (-not $unzipDir) {
     $unzipDir = Join-Path $Path "unzipped"
     Expand-Archive -Path $ZipFile -DestinationPath $unzipDir
+    
+    # Cleanup temporary files
+    if ($downloaded) {
+        Remove-Item -Path $ZipFile
+    }
+    
     $unzipped = $true
 }