Add -enable-pss flag to the init command, to be used for accessing experimental init logic

Author: SarahFrench

internal/command/arguments/init.go

@@ -73,6 +73,11 @@ type Init struct {
 	PluginPath FlagStringSlice
 
 	Args []string
+
+	// The -enable-pss flag is used in control flow logic in the init command.
+	// TODO(SarahFrench/radeksimko): Remove this once the feature is no longer
+	// experimental
+	EnablePssExperiment bool
 }
 
 // ParseInit processes CLI arguments, returning an Init value and errors.
@@ -107,6 +112,9 @@ func ParseInit(args []string) (*Init, tfdiags.Diagnostics) {
 	cmdFlags.Var(&init.BackendConfig, "backend-config", "")
 	cmdFlags.Var(&init.PluginPath, "plugin-dir", "plugin directory")
 
+	// Used for enabling experimental code that's invoked before configuration is parsed.
+	cmdFlags.BoolVar(&init.EnablePssExperiment, "enable-pss", false, "Enable the PSS experiment")
+
 	if err := cmdFlags.Parse(args); err != nil {
 		diags = diags.Append(tfdiags.Sourceless(
 			tfdiags.Error,

internal/command/init.go

@@ -50,6 +50,16 @@ func (c *InitCommand) Run(args []string) int {
 		view.Diagnostics(diags)
 		return 1
 	}
+
+	// The else condition below invokes the original logic of the init command.
+	// An experimental version of the init code will be used if:
+	// 	> The user uses an experimental version of TF (alpha or built from source)
+	//  > The flag -enable-pss is passed to the init command.
+	if c.Meta.AllowExperimentalFeatures && initArgs.EnablePssExperiment {
+		// TODO(SarahFrench/radeksimko): Remove forked init logic once feature is no longer experimental
+		panic("pss: experimental init code hasn't been added yet")
+	} else {
+	}
 	return c.run(initArgs, view)
 }