Alternative shell support

cli/azd/pkg/tools/powershell/powershell.go

@@ -6,6 +6,7 @@ package powershell
 import (
 	"context"
 	"fmt"
+	"runtime"
 	"strings"
 
 	"github.com/azure/azure-dev/cli/azd/internal"
@@ -54,11 +55,26 @@ func checkPath(options tools.ExecOptions) (err error) {
 // Executes the specified powershell script
 // When interactive is true will attach to stdin, stdout & stderr
 func (bs *powershellScript) Execute(ctx context.Context, path string, options tools.ExecOptions) (exec.RunResult, error) {
-	if err := bs.checkInstalled(options); err != nil {
-		return exec.RunResult{}, &internal.ErrorWithSuggestion{
-			Err: err,
-			Suggestion: fmt.Sprintf("PowerShell 7 is not installed or not in the path. To install PowerShell 7, visit %s",
-				output.WithLinkFormat("https://learn.microsoft.com/powershell/scripting/install/installing-powershell")),
+	noPwshError := bs.checkInstalled(options)
+	if noPwshError != nil {
+
+		if runtime.GOOS != "windows" {
+			return exec.RunResult{}, &internal.ErrorWithSuggestion{
+				Err: noPwshError,
+				Suggestion: fmt.Sprintf(
+					"PowerShell 7 is not installed or not in the path. To install PowerShell 7, visit %s",
+					output.WithLinkFormat("https://learn.microsoft.com/powershell/scripting/install/installing-powershell")),
+			}
+		}
+
+		options.UserPwsh = "powershell"
+		if err := bs.checkInstalled(options); err != nil {
+			return exec.RunResult{}, &internal.ErrorWithSuggestion{
+				Err: err,
+				Suggestion: fmt.Sprintf(
+					"Make sure pwsh (PowerShell 7) or powershell (PowerShell 5) is installed on your system, visit %s",
+					output.WithLinkFormat("https://learn.microsoft.com/powershell/scripting/install/installing-powershell")),
+			}
 		}
 	}
 
@@ -75,5 +91,18 @@ func (bs *powershellScript) Execute(ctx context.Context, path string, options to
 		runArgs = runArgs.WithStdOut(options.StdOut)
 	}
 
-	return bs.commandRunner.Run(ctx, runArgs)
+	result, err := bs.commandRunner.Run(ctx, runArgs)
+	if err != nil {
+		if noPwshError != nil {
+			err = &internal.ErrorWithSuggestion{
+				Err: err,
+				Suggestion: fmt.Sprintf("pwsh (PowerShell 7) was not found and powershell (PowerShell 5) was automatically"+
+					" used instead. You can try installing pwsh and trying again in case this script is not compatible "+
+					"with PowerShell 5. See: %s",
+					output.WithLinkFormat("https://learn.microsoft.com/powershell/scripting/install/installing-powershell")),
+			}
+		}
+	}
+
+	return result, err
 }

cli/azd/pkg/tools/powershell/powershell_test.go

@@ -6,6 +6,8 @@ package powershell
 import (
 	"context"
 	"errors"
+	"fmt"
+	"runtime"
 	"strings"
 	"testing"
 
@@ -57,6 +59,57 @@ func Test_Powershell_Execute(t *testing.T) {
 		require.NoError(t, err)
 	})
 
+	t.Run("Success - alternative", func(t *testing.T) {
+		if runtime.GOOS != "windows" {
+			t.Skip("pwsh alternative is only for Windows")
+		}
+		mockContext := mocks.NewMockContext(context.Background())
+
+		// #nosec G101
+		userPwsh := "pwsh -NoProfile"
+		mockContext.CommandRunner.When(func(args exec.RunArgs, command string) bool {
+			return strings.Contains(args.Cmd, userPwsh)
+		}).RespondFn(func(args exec.RunArgs) (exec.RunResult, error) {
+			require.Equal(t, userPwsh, args.Cmd)
+			require.Equal(t, workingDir, args.Cwd)
+			require.Equal(t, scriptPath, args.Args[0])
+			require.Equal(t, env, args.Env)
+
+			return exec.NewRunResult(1, "not found", "not found"), nil
+		})
+
+		userPwshAlternative := "powershell"
+		mockContext.CommandRunner.When(func(args exec.RunArgs, command string) bool {
+			return strings.Contains(args.Cmd, userPwshAlternative)
+		}).RespondFn(func(args exec.RunArgs) (exec.RunResult, error) {
+			require.Equal(t, userPwshAlternative, args.Cmd)
+			require.Equal(t, workingDir, args.Cwd)
+			require.Equal(t, scriptPath, args.Args[0])
+			require.Equal(t, env, args.Env)
+
+			return exec.NewRunResult(0, "", ""), nil
+		})
+
+		PowershellScript := NewPowershellScriptWithMockCheckPath(
+			mockContext.CommandRunner,
+			workingDir,
+			env,
+			func(options tools.ExecOptions) error {
+				if strings.Contains(options.UserPwsh, "pwsh") {
+					return fmt.Errorf("failed to find PowerShell executable")
+				}
+				return nil
+			})
+		runResult, err := PowershellScript.Execute(
+			*mockContext.Context,
+			scriptPath,
+			tools.ExecOptions{UserPwsh: userPwsh, Interactive: to.Ptr(true)},
+		)
+
+		require.NotNil(t, runResult)
+		require.NoError(t, err)
+	})
+
 	t.Run("Error", func(t *testing.T) {
 		mockContext := mocks.NewMockContext(context.Background())
 
@@ -86,7 +139,13 @@ func Test_Powershell_Execute(t *testing.T) {
 	t.Run("NoPowerShellInstalled", func(t *testing.T) {
 		mockContext := mocks.NewMockContext(context.Background())
 
-		PowershellScript := NewPowershellScript(mockContext.CommandRunner, workingDir, env)
+		PowershellScript := NewPowershellScriptWithMockCheckPath(
+			mockContext.CommandRunner,
+			workingDir,
+			env,
+			func(options tools.ExecOptions) error {
+				return fmt.Errorf("failed to find PowerShell executable")
+			})
 		_, err := PowershellScript.Execute(
 			*mockContext.Context,
 			scriptPath,