Allow to inject definitions of resource type outside from package

migration/migration.go

@@ -7,7 +7,8 @@ import (
 	"text/template"
 
 	tfjson "github.com/hashicorp/terraform-json"
-	"github.com/mitchellh/mapstructure"
+	"github.com/minamijoyo/tfedit/migration/schema"
+	_ "github.com/minamijoyo/tfedit/migration/schema/aws"
 )
 
 var migrationTemplate string = `migration "state" "awsv4upgrade" {
@@ -19,15 +20,6 @@ var migrationTemplate string = `migration "state" "awsv4upgrade" {
 }
 `
 
-type AWSS3BucketACLFilterResource struct {
-	Bucket string
-	ACL    string
-}
-
-func (r *AWSS3BucketACLFilterResource) ID() string {
-	return r.Bucket + "," + r.ACL
-}
-
 func Generate(planJSON []byte) ([]byte, error) {
 	var plan tfjson.Plan
 	if err := json.Unmarshal(planJSON, &plan); err != nil {
@@ -39,9 +31,8 @@ func Generate(planJSON []byte) ([]byte, error) {
 		if rc.Change.Actions.Create() {
 			address := rc.Address
 			after := rc.Change.After.(map[string]interface{})
-			var r AWSS3BucketACLFilterResource
-			mapstructure.Decode(after, &r)
-			migrateAction := fmt.Sprintf("import %s %s", address, r.ID())
+			importID := schema.ImportID(rc.Type, after)
+			migrateAction := fmt.Sprintf("import %s %s", address, importID)
 			migrateActions = append(migrateActions, migrateAction)
 		}
 	}

migration/schema/aws/s3.go

@@ -0,0 +1,19 @@
+package aws
+
+import "github.com/minamijoyo/tfedit/migration/schema"
+
+func init() {
+	RegisterSchema()
+}
+
+func RegisterSchema() {
+	importIDMap := map[string]schema.ImportIDFunc{
+		"aws_s3_bucket_acl": func(r schema.Resource) string {
+			return r["bucket"].(string) + "," + r["acl"].(string)
+		},
+	}
+
+	for k, v := range importIDMap {
+		schema.RegisterImportIDFunc(k, v)
+	}
+}

migration/schema/dictionary.go

@@ -0,0 +1,33 @@
+package schema
+
+type Resource map[string]interface{}
+type ImportIDFunc func(r Resource) string
+
+type Dictionary struct {
+	importIDMap map[string]ImportIDFunc
+}
+
+func NewDictionary() *Dictionary {
+	return &Dictionary{
+		importIDMap: make(map[string]ImportIDFunc),
+	}
+}
+
+func (d *Dictionary) RegisterImportIDFunc(resourceType string, f ImportIDFunc) {
+	d.importIDMap[resourceType] = f
+}
+
+func (d *Dictionary) ImportID(resourceType string, r Resource) string {
+	f := d.importIDMap[resourceType]
+	return f(r)
+}
+
+var defaultDictionary = NewDictionary()
+
+func RegisterImportIDFunc(resourceType string, f ImportIDFunc) {
+	defaultDictionary.RegisterImportIDFunc(resourceType, f)
+}
+
+func ImportID(resourceType string, r Resource) string {
+	return defaultDictionary.ImportID(resourceType, r)
+}