From f1c58c33b6bb4d1481b2b7f8df5bac98ccc28736 Mon Sep 17 00:00:00 2001
From: Thomas Boop <52323235+thboop@users.noreply.github.com>
Date: Wed, 23 Oct 2019 11:24:02 -0400
Subject: [PATCH] Default to pwsh with powershell as a fallback (#142)

* Default to pwsh with powershell as a fallback

* Update releaseNote.md

* clean up code
---
 releaseNote.md                              |  1 +
 src/Runner.Worker/Handlers/ScriptHandler.cs | 20 ++++++++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/releaseNote.md b/releaseNote.md
index b442870a4..723e30b7f 100644
--- a/releaseNote.md
+++ b/releaseNote.md
@@ -1,5 +1,6 @@
 ## Features
   - Set Default shell to powershell for windows runners (#135)
+  - Use Powershell as fallback if Powershell Core is not available for default shell on windows (#142)
 
 ## Bugs
   - Removed unintended additional fields on error and warning commands (#137)
diff --git a/src/Runner.Worker/Handlers/ScriptHandler.cs b/src/Runner.Worker/Handlers/ScriptHandler.cs
index 182913049..6564863a6 100644
--- a/src/Runner.Worker/Handlers/ScriptHandler.cs
+++ b/src/Runner.Worker/Handlers/ScriptHandler.cs
@@ -60,10 +60,16 @@ namespace GitHub.Runner.Worker.Handlers
             if (string.IsNullOrEmpty(shell))
             {
 #if OS_WINDOWS
-                shellCommand = "powershell";
+                shellCommand = "pwsh";
                 if(validateShellOnHost)
                 {
-                    shellCommandPath = WhichUtil.Which(shellCommand, true, Trace);
+                    shellCommandPath = WhichUtil.Which(shellCommand, require: false, Trace);
+                    if (string.IsNullOrEmpty(shellCommandPath))
+                    {
+                        shellCommand = "powershell";
+                        Trace.Info($"Defaulting to {shellCommand}");
+                        shellCommandPath = WhichUtil.Which(shellCommand, require: true, Trace);
+                    }
                 }
 #else
                 shellCommand = "sh";
@@ -143,8 +149,14 @@ namespace GitHub.Runner.Worker.Handlers
             if (string.IsNullOrEmpty(shell))
             {
 #if OS_WINDOWS
-                shellCommand = "powershell";
-                commandPath = WhichUtil.Which(shellCommand, true, Trace);
+                shellCommand = "pwsh";
+                commandPath = WhichUtil.Which(shellCommand, require: false, Trace);
+                if (string.IsNullOrEmpty(commandPath))
+                {
+                    shellCommand = "powershell";
+                    Trace.Info($"Defaulting to {shellCommand}");
+                    commandPath = WhichUtil.Which(shellCommand, require: true, Trace);
+                }
                 ArgUtil.NotNullOrEmpty(commandPath, "Default Shell");
 #else
                 shellCommand = "sh";