Support pwsh executable name for powershell

This updates the powershell detection to look for the `pwsh` executable
    and use it when the powershell executable is not available.

lib/vagrant/util/powershell.rb

@@ -14,28 +14,44 @@ module Vagrant
       MINIMUM_REQUIRED_VERSION = 3
       # Number of seconds to wait while attempting to get powershell version
       DEFAULT_VERSION_DETECTION_TIMEOUT = 30
+      # Names of the powershell executable
+      POWERSHELL_NAMES = ["powershell", "pwsh"].map(&:freeze).freeze
+      # Paths to powershell executable
+      POWERSHELL_PATHS = [
+        "%WINDIR%/WindowsPowerShell/v1.0",
+        "%PROGRAMFILES%/PowerShell/7",
+        "%PROGRAMFILES%/PowerShell/6"
+      ].map(&:freeze).freeze
+
       LOGGER = Log4r::Logger.new("vagrant::util::powershell")
 
       # @return [String|nil] a powershell executable, depending on environment
       def self.executable
         if !defined?(@_powershell_executable)
-          @_powershell_executable = "powershell"
+          # First start with detecting executable on configured path
+          POWERSHELL_NAMES.detect do |psh|
+            return @_powershell_executable = psh if Which.which(psh)
+            psh += ".exe"
+            return @_powershell_executable = psh if Which.which(psh)
+          end
 
-          if Which.which(@_powershell_executable).nil?
-            # Try to use WSL interoperability if PowerShell is not symlinked to
-            # the container.
-            if Platform.wsl?
-              @_powershell_executable += ".exe"
+          # Now attempt with paths
+          paths = POWERSHELL_PATHS.map do |ppath|
+            result = Util::Subprocess.execute("cmd.exe", "/c", "echo #{ppath}")
+            result.stdout.gsub("\"", "").strip if result.exit_code == 0
+          end.compact
 
-              if Which.which(@_powershell_executable).nil?
-                @_powershell_executable = "/mnt/c/Windows/System32/WindowsPowerShell/v1.0/powershell.exe"
+          paths.each do |psh_path|
+            POWERSHELL_NAMES.each do |psh|
+              path = File.join(psh_path, psh)
+              return @_powershell_executable = path if Which.which(path)
 
-                if Which.which(@_powershell_executable).nil?
-                  @_powershell_executable = nil
-                end
-              end
-            else
-              @_powershell_executable = nil
+              path += ".exe"
+              return @_powershell_executable = path if Which.which(path)
+
+              # Finally test the msys2 style path
+              path = path.sub(/^([A-Za-z]):/, "/mnt/\\1")
+              return @_powershell_executable = path if Which.which(path)
             end
           end
         end

test/unit/vagrant/util/powershell_test.rb

@@ -45,47 +45,50 @@ describe Vagrant::Util::PowerShell do
   end
 
   describe ".executable" do
-    before{ allow(Vagrant::Util::Platform).to receive(:wsl?).and_return(false) }
+    before do
+      allow(Vagrant::Util::Which).to receive(:which).and_return(nil)
+      allow(Vagrant::Util::Subprocess).to receive(:execute) do |*args|
+        Vagrant::Util::Subprocess::Result.new(0, args.last.sub("echo ", ""), "")
+      end
+    end
 
-    context "when found in PATH" do
-      before{ expect(Vagrant::Util::Which).to receive(:which).with("powershell").and_return(true) }
+    context "when powershell found in PATH" do
+      before{ expect(Vagrant::Util::Which).to receive(:which).
+          with("powershell").and_return(true) }
 
       it "should return powershell string" do
         expect(described_class.executable).to eq("powershell")
       end
     end
 
-    context "when not found in PATH" do
-      before{ expect(Vagrant::Util::Which).to receive(:which).with("powershell").and_return(nil) }
+    context "when pwsh found in PATH" do
+      before { expect(Vagrant::Util::Which).to receive(:which).
+          with("pwsh").and_return(true) }
 
+      it "should return pwsh string" do
+        expect(described_class.executable).to eq("pwsh")
+      end
+    end
+
+    context "when not found in PATH" do
       it "should return nil" do
         expect(described_class.executable).to be_nil
       end
 
-      context "when within WSL" do
-        before do
-          allow(Vagrant::Util::Which).to receive(:which).with(/powershell/).and_return(nil)
-          expect(Vagrant::Util::Platform).to receive(:wsl?).and_return(true)
-        end
+      it "should check PATH with .exe extension" do
+        expect(Vagrant::Util::Which).to receive(:which).with("powershell.exe")
+        described_class.executable
+      end
 
-        it "should check PATH with .exe extension" do
-          expect(Vagrant::Util::Which).to receive(:which).with("powershell.exe")
-          described_class.executable
-        end
+      it "should return powershell.exe when found" do
+        expect(Vagrant::Util::Which).to receive(:which).
+          with("powershell.exe").and_return(true)
+        expect(described_class.executable).to eq("powershell.exe")
+      end
 
-        it "should return powershell.exe when found" do
-          expect(Vagrant::Util::Which).to receive(:which).with("powershell.exe").and_return(true)
-          expect(described_class.executable).to eq("powershell.exe")
-        end
-
-        it "should return nil when not found" do
-          expect(described_class.executable).to be_nil
-        end
-
-        it "should check for powershell with full path" do
-          expect(Vagrant::Util::Which).to receive(:which).with(/Windows\/System32.+powershell.exe/)
-          described_class.executable
-        end
+      it "should check for powershell with full path" do
+        expect(Vagrant::Util::Which).to receive(:which).with(/WindowsPowerShell\/v1.0\/powershell.exe/)
+        described_class.executable
       end
     end
   end