add alpha command to test dry-run

Signed-off-by: Guillaume Lours <705411+glours@users.noreply.github.com>

cmd/compose/alpha.go

@@ -15,6 +15,8 @@
 package compose
 
 import (
+	"context"
+
 	"github.com/docker/compose/v2/pkg/api"
 	"github.com/spf13/cobra"
 )
@@ -29,6 +31,27 @@ func alphaCommand(p *ProjectOptions, backend api.Service) *cobra.Command {
 			"experimentalCLI": "true",
 		},
 	}
-	cmd.AddCommand(watchCommand(p, backend))
+	cmd.AddCommand(
+		watchCommand(p, backend),
+		dryRunRedirectCommand(p),
+	)
+	return cmd
+}
+
+// Temporary alpha command as the dry-run will be implemented with a flag
+func dryRunRedirectCommand(p *ProjectOptions) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "dry-run -- [COMMAND...]",
+		Short: "EXPERIMENTAL - Dry run command allow you to test a command without applying changes",
+		PreRunE: Adapt(func(ctx context.Context, args []string) error {
+			return nil
+		}),
+		RunE: AdaptCmd(func(ctx context.Context, cmd *cobra.Command, args []string) error {
+			rootCmd := cmd.Root()
+			rootCmd.SetArgs(append([]string{"compose", "--dry-run"}, args...))
+			return rootCmd.Execute()
+		}),
+		ValidArgsFunction: completeServiceNames(p),
+	}
 	return cmd
 }