From 47b4aeb80fb4e61638f1ecfce596dc2b66390d1e Mon Sep 17 00:00:00 2001
From: Masayuki Morita <minamijoyo@gmail.com>
Date: Wed, 20 Apr 2022 22:30:13 +0900
Subject: [PATCH] Rename Migration to File

---
 migration/file.go      | 51 +++++++++++++++++++++++++++++++++++++++++
 migration/migration.go | 52 +++---------------------------------------
 2 files changed, 54 insertions(+), 49 deletions(-)
 create mode 100644 migration/file.go

diff --git a/migration/file.go b/migration/file.go
new file mode 100644
index 0000000..a990ae1
--- /dev/null
+++ b/migration/file.go
@@ -0,0 +1,51 @@
+package migration
+
+import (
+	"bytes"
+	"fmt"
+	"text/template"
+)
+
+// File is a type which is equivalent to tfmigrate.StateMigratorConfig of
+// minamijoyo/tfmigrate.
+// The current implementation doesn't encode migration actions to a file
+// directly with gohcl, so we avoid to depend on tfmigrate's type and we define
+// only what we need here.
+type File struct {
+	// Dir is a working directory for executing terraform command.
+	Dir string
+	// Actions is a list of state action.
+	Actions []string
+}
+
+var migrationTemplate = `migration "state" "awsv4upgrade" {
+  actions = [
+  {{- range . }}
+    "{{ . }}",
+  {{- end }}
+  ]
+}
+`
+
+var compiledMigrationTemplate = template.Must(template.New("migration").Parse(migrationTemplate))
+
+// AppendAction appends an action to migration.
+func (f *File) AppendAction(action string) {
+	f.Actions = append(f.Actions, action)
+}
+
+// Render converts a state migration config to bytes
+func (f *File) Render() ([]byte, error) {
+	// Encoding StateMigratorConfig directly with gohcl has some problems.
+	// An array contains multiple elements is output as one line. It's not readable
+	// for multiple actions. In additon, the default value is set explicitly, it's
+	// not only redundant but also increases cognitive load for user who isn't
+	// familiar with tfmigrate.
+	// So we use text/template to render a migration file.
+	var output bytes.Buffer
+	if err := compiledMigrationTemplate.Execute(&output, f.Actions); err != nil {
+		return nil, fmt.Errorf("failed to render migration file: %s", err)
+	}
+
+	return output.Bytes(), nil
+}
diff --git a/migration/migration.go b/migration/migration.go
index 30431e9..5a67c4e 100644
--- a/migration/migration.go
+++ b/migration/migration.go
@@ -1,76 +1,30 @@
 package migration
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
-	"text/template"
 
 	tfjson "github.com/hashicorp/terraform-json"
 	"github.com/minamijoyo/tfedit/migration/schema"
 	_ "github.com/minamijoyo/tfedit/migration/schema/aws" // Register schema for aws
 )
 
-// Migration is a type which is equivalent to tfmigrate.StateMigratorConfig of
-// minamijoyo/tfmigrate.
-// The current implementation doesn't encode migration actions to a file
-// directly with gohcl, so we avoid to depend on tfmigrate's type and we define
-// only what we need here.
-type Migration struct {
-	// Dir is a working directory for executing terraform command.
-	Dir string
-	// Actions is a list of state action.
-	Actions []string
-}
-
-var migrationTemplate = `migration "state" "awsv4upgrade" {
-  actions = [
-  {{- range . }}
-    "{{ . }}",
-  {{- end }}
-  ]
-}
-`
-
-var compiledMigrationTemplate = template.Must(template.New("migration").Parse(migrationTemplate))
-
-// AppendAction appends an action to migration.
-func (m *Migration) AppendAction(action string) {
-	m.Actions = append(m.Actions, action)
-}
-
-// Encode converts a state migration config to bytes
-func (m *Migration) Encode() ([]byte, error) {
-	// Encoding StateMigratorConfig directly with gohcl has some problems.
-	// An array contains multiple elements is output as one line. It's not readable
-	// for multiple actions. In additon, the default value is set explicitly, it's
-	// not only redundant but also increases cognitive load for user who isn't
-	// familiar with tfmigrate.
-	// So we use text/template to render a migration file.
-	var output bytes.Buffer
-	if err := compiledMigrationTemplate.Execute(&output, m.Actions); err != nil {
-		return nil, fmt.Errorf("failed to render migration file: %s", err)
-	}
-
-	return output.Bytes(), nil
-}
-
 func Generate(planJSON []byte) ([]byte, error) {
 	var plan tfjson.Plan
 	if err := json.Unmarshal(planJSON, &plan); err != nil {
 		return nil, fmt.Errorf("failed to parse plan file: %s", err)
 	}
 
-	var migration Migration
+	var file File
 	for _, rc := range plan.ResourceChanges {
 		if rc.Change.Actions.Create() {
 			address := rc.Address
 			after := rc.Change.After.(map[string]interface{})
 			importID := schema.ImportID(rc.Type, after)
 			migrateAction := fmt.Sprintf("import %s %s", address, importID)
-			migration.AppendAction(migrateAction)
+			file.AppendAction(migrateAction)
 		}
 	}
 
-	return migration.Encode()
+	return file.Render()
 }