chore(kv): rename Name method to MigrationName for clarity

kv/index.go

@@ -179,6 +179,9 @@ func indexKeyParts(indexKey []byte) (fk, pk []byte, err error) {
 	return
 }
 
+// ensure IndexMigration implements MigrationSpec
+var _ MigrationSpec = (*IndexMigration)(nil)
+
 // IndexMigration is a migration for adding and removing an index.
 // These are constructed via the Index.Migration function.
 type IndexMigration struct {
@@ -187,7 +190,7 @@ type IndexMigration struct {
 }
 
 // Name returns a readable name for the index migration.
-func (i *IndexMigration) Name() string {
+func (i *IndexMigration) MigrationName() string {
 	return fmt.Sprintf("add index %q", string(i.IndexBucket()))
 }
 
@@ -198,7 +201,7 @@ func (i *IndexMigration) Up(ctx context.Context, store Store) (err error) {
 			return nil
 		}
 
-		return fmt.Errorf("migration (up) %s: %w", i.Name(), err)
+		return fmt.Errorf("migration (up) %s: %w", i.MigrationName(), err)
 	}
 
 	if err = i.initialize(ctx, store); err != nil {
@@ -212,7 +215,7 @@ func (i *IndexMigration) Up(ctx context.Context, store Store) (err error) {
 // Down deletes all entries from the index.
 func (i *IndexMigration) Down(ctx context.Context, store Store) error {
 	if err := i.DeleteAll(ctx, store); err != nil {
-		return fmt.Errorf("migration (down) %s: %w", i.Name(), err)
+		return fmt.Errorf("migration (down) %s: %w", i.MigrationName(), err)
 	}
 
 	return nil

kv/migration.go

@@ -54,7 +54,7 @@ type Migration struct {
 // It describes the name of the migration and up and down operations
 // needed to fulfill the migration.
 type MigrationSpec interface {
-	Name() string
+	MigrationName() string
 	Up(ctx context.Context, store Store) error
 	Down(ctx context.Context, store Store) error
 }
@@ -75,7 +75,7 @@ func NewAnonymousMigration(name string, up, down MigrationFunc) AnonymousMigrati
 }
 
 // Name returns the name of the migration.
-func (a AnonymousMigration) Name() string { return a.name }
+func (a AnonymousMigration) MigrationName() string { return a.name }
 
 // Up calls the underlying up migration func.
 func (a AnonymousMigration) Up(ctx context.Context, store Store) error { return a.up(ctx, store) }
@@ -87,8 +87,8 @@ func (a AnonymousMigration) Down(ctx context.Context, store Store) error { retur
 // It takes a list of migration specifications and undo (down) all or apply (up) outstanding migrations.
 // It records the state of the world in store under the migrations bucket.
 type Migrator struct {
-	logger     *zap.Logger
-	Migrations []MigrationSpec
+	logger         *zap.Logger
+	MigrationSpecs []MigrationSpec
 
 	now func() time.Time
 }
@@ -107,7 +107,7 @@ func NewMigrator(logger *zap.Logger, ms ...MigrationSpec) *Migrator {
 
 // AddMigrations appends the provided migration specs onto the Migrator.
 func (m *Migrator) AddMigrations(ms ...MigrationSpec) {
-	m.Migrations = append(m.Migrations, ms...)
+	m.MigrationSpecs = append(m.MigrationSpecs, ms...)
 }
 
 // Initialize creates the migration bucket if it does not yet exist.
@@ -127,10 +127,10 @@ func (m *Migrator) List(ctx context.Context, store Store) (migrations []Migratio
 	}
 
 	migrationsLen := len(migrations)
-	for idx, migration := range m.Migrations[migrationsLen:] {
+	for idx, spec := range m.MigrationSpecs[migrationsLen:] {
 		migration := Migration{
 			ID:   influxdb.ID(migrationsLen + idx + 1),
-			Name: migration.Name(),
+			Name: spec.MigrationName(),
 		}
 
 		migrations = append(migrations, migration)
@@ -167,11 +167,11 @@ func (m *Migrator) Up(ctx context.Context, store Store) error {
 		return wrapErr(err)
 	}
 
-	for idx, mig := range m.Migrations[lastMigration:] {
+	for idx, spec := range m.MigrationSpecs[lastMigration:] {
 		startedAt := m.now()
 		migration := Migration{
 			ID:        influxdb.ID(lastMigration + idx + 1),
-			Name:      mig.Name(),
+			Name:      spec.MigrationName(),
 			StartedAt: &startedAt,
 		}
 
@@ -181,7 +181,7 @@ func (m *Migrator) Up(ctx context.Context, store Store) error {
 			return wrapErr(err)
 		}
 
-		if err := mig.Up(ctx, store); err != nil {
+		if err := spec.Up(ctx, store); err != nil {
 			return wrapErr(err)
 		}
 
@@ -229,7 +229,7 @@ func (m *Migrator) Down(ctx context.Context, store Store) (err error) {
 				MigrationSpec
 				Migration
 			}{
-				m.Migrations[int(id)-1],
+				m.MigrationSpecs[int(id)-1],
 				mig,
 			},
 		)
@@ -284,12 +284,12 @@ func (m *Migrator) walk(ctx context.Context, store Store, fn func(id influxdb.ID
 			}
 
 			idx := int(id) - 1
-			if idx >= len(m.Migrations) {
+			if idx >= len(m.MigrationSpecs) {
 				return fmt.Errorf("migration %q: %w", migration.Name, ErrMigrationSpecNotFound)
 			}
 
-			if mig := m.Migrations[idx]; mig.Name() != migration.Name {
-				return fmt.Errorf("expected migration %q, found %q", mig.Name(), migration.Name)
+			if spec := m.MigrationSpecs[idx]; spec.MigrationName() != migration.Name {
+				return fmt.Errorf("expected migration %q, found %q", spec.MigrationName(), migration.Name)
 			}
 
 			if migration.FinishedAt != nil {

kv/service.go

@@ -77,6 +77,7 @@ func NewService(log *zap.Logger, kv Store, configs ...ServiceConfig) *Service {
 				return nil
 			},
 		),
+		// and new migrations below here (and move this comment down):
 	)
 
 	if len(configs) > 0 {
@@ -127,6 +128,9 @@ func (s *Service) Initialize(ctx context.Context) error {
 }
 
 func (s *Service) initializeAll(ctx context.Context, store Store) error {
+	// please do not initialize anymore buckets here
+	// add them as a new migration to the list of migrations
+	// defined in NewService.
 	if err := store.Update(ctx, func(tx Tx) error {
 		if err := s.initializeAuths(ctx, tx); err != nil {
 			return err

testing/migration.go

@@ -316,7 +316,7 @@ func Migrator(t *testing.T, store kv.Store, newMigrator func(*zap.Logger, NowFun
 
 	t.Run("List() missing migration spec errors as expected", func(t *testing.T) {
 		// remove last specification from migration list
-		migrator.Migrations = migrator.Migrations[:len(migrator.Migrations)-1]
+		migrator.MigrationSpecs = migrator.MigrationSpecs[:len(migrator.MigrationSpecs)-1]
 		// list migration again
 		_, err := migrator.List(ctx, store)
 		if !errors.Is(err, kv.ErrMigrationSpecNotFound) {
@@ -335,7 +335,7 @@ type spyMigrationSpec struct {
 	downCalled int
 }
 
-func (s *spyMigrationSpec) Name() string {
+func (s *spyMigrationSpec) MigrationName() string {
 	return s.name
 }