Allow to pass a name label of migration block

migration/analyzer.go

@@ -32,13 +32,13 @@ func NewDefaultPlanAnalyzer() PlanAnalyzer {
 func (a *defaultPlanAnalyzer) Analyze(plan *Plan) *StateMigration {
 	subject := NewSubject(plan)
 
-	var migration StateMigration
+	migration := NewStateMigration("fromplan")
 	current := subject
 	for _, r := range a.resolvers {
 		next, actions := r.Resolve(current)
 		migration.AppendActions(actions...)
 		current = next
 	}
 
-	return &migration
+	return migration
 }

migration/migration.go

@@ -6,18 +6,20 @@ import (
 	"text/template"
 )
 
-// StateMigration is a type which is equivalent to tfmigrate.StateMigratorConfig of
-// minamijoyo/tfmigrate.
+// StateMigration is a type which corresponds to tfmigrate.StateMigratorConfig
+// and config.MigrationBlock in minamijoyo/tfmigrate.
 // The current implementation doesn't encode migration actions to a file
 // directly with gohcl, so we define only what we need here.
 type StateMigration struct {
-	// Dir is a working directory for executing terraform command.
+	// A name label of migration block
+	Name string
+	// A working directory for executing terraform command.
 	Dir string
-	// Actions is a list of state action.
+	// A list of state action.
 	Actions []StateAction
 }
 
-var migrationTemplate = `migration "state" "awsv4upgrade" {
+var migrationTemplate = `migration "state" "{{ .Name }}" {
   actions = [
   {{- range .Actions }}
     "{{ .MigrationAction }}",
@@ -28,6 +30,13 @@ var migrationTemplate = `migration "state" "awsv4upgrade" {
 
 var compiledMigrationTemplate = template.Must(template.New("migration").Parse(migrationTemplate))
 
+// NewStateMigration returns a new instance of StateMigration.
+func NewStateMigration(name string) *StateMigration {
+	return &StateMigration{
+		Name: name,
+	}
+}
+
 // AppendActions appends a list of actions to migration.
 func (m *StateMigration) AppendActions(actions ...StateAction) {
 	m.Actions = append(m.Actions, actions...)