Feat/run migration (#1303)

* feat: add RunMigration method

* .

Author: vmihailenco

internal/dbtest/migrate_test.go

@@ -55,6 +55,7 @@ func TestMigrate(t *testing.T) {
 	tests := []Test{
 		{run: testMigrateUpAndDown},
 		{run: testMigrateUpError},
+		{run: testRunMigration},
 	}
 
 	testEachDB(t, func(t *testing.T, dbName string, db *bun.DB) {
@@ -180,6 +181,64 @@ func testMigrateUpError(t *testing.T, db *bun.DB) {
 	require.Equal(t, []string{"down2", "down1"}, history)
 }
 
+func testRunMigration(t *testing.T, db *bun.DB) {
+	ctx := context.Background()
+	cleanupMigrations(t, ctx, db)
+
+	var history []string
+
+	migrations := migrate.NewMigrations()
+	migrations.Add(migrate.Migration{
+		Name: "20060102150405",
+		Up: func(ctx context.Context, migrator *migrate.Migrator, migration *migrate.Migration) error {
+			history = append(history, "up1")
+			return nil
+		},
+	})
+	migrations.Add(migrate.Migration{
+		Name: "20060102160405",
+		Up: func(ctx context.Context, migrator *migrate.Migrator, migration *migrate.Migration) error {
+			history = append(history, "up2")
+			return nil
+		},
+	})
+
+	m := migrate.NewMigrator(db, migrations,
+		migrate.WithTableName(migrationsTable),
+		migrate.WithLocksTableName(migrationLocksTable),
+	)
+	require.NoError(t, m.Reset(ctx))
+
+	_, err := m.Migrate(ctx)
+	require.NoError(t, err)
+	require.Equal(t, []string{"up1", "up2"}, history)
+
+	appliedBefore, err := m.AppliedMigrations(ctx)
+	require.NoError(t, err)
+	migrationIDs := func(ms migrate.MigrationSlice) []int64 {
+		ids := make([]int64, len(ms))
+		for i := range ms {
+			ids[i] = ms[i].ID
+		}
+		return ids
+	}
+	migrationsWithStatus, err := m.MigrationsWithStatus(ctx)
+	require.NoError(t, err)
+	require.Len(t, migrationsWithStatus, 2)
+
+	targetID := migrationsWithStatus[0].ID
+	require.NotZero(t, targetID)
+
+	history = nil
+	err = m.RunMigration(ctx, targetID)
+	require.NoError(t, err)
+	require.Equal(t, []string{"up1"}, history)
+
+	appliedAfter, err := m.AppliedMigrations(ctx)
+	require.NoError(t, err)
+	require.ElementsMatch(t, migrationIDs(appliedBefore), migrationIDs(appliedAfter))
+}
+
 // newAutoMigratorOrSkip creates an AutoMigrator configured to use test migratins/locks
 // tables and dedicated migrations directory. If an AutoMigrator cannob be created because
 // the dialect doesn't support either schema inspections or migrations, the test will be *skipped*

migrate/migrator.go

@@ -207,6 +207,45 @@ func (m *Migrator) Migrate(ctx context.Context, opts ...MigrationOption) (*Migra
 	return group, nil
 }
 
+// RunMigration runs the up migration with the given ID without marking it as applied.
+// It runs the migration even if it is already marked as applied.
+func (m *Migrator) RunMigration(
+	ctx context.Context, migrationID int64, opts ...MigrationOption,
+) error {
+	cfg := newMigrationConfig(opts)
+
+	if err := m.validate(); err != nil {
+		return err
+	}
+	if migrationID == 0 {
+		return errors.New("migrate: migration id must be greater than zero")
+	}
+
+	migrations, _, err := m.migrationsWithStatus(ctx)
+	if err != nil {
+		return err
+	}
+
+	var migration *Migration
+	for i := range migrations {
+		if migrations[i].ID == migrationID {
+			migration = &migrations[i]
+			break
+		}
+	}
+	if migration == nil {
+		return fmt.Errorf("migrate: migration with id %d not found", migrationID)
+	}
+	if migration.Up == nil {
+		return fmt.Errorf("migrate: migration %s does not have up migration", migration.Name)
+	}
+	if cfg.nop {
+		return nil
+	}
+
+	return migration.Up(ctx, m, migration)
+}
+
 func (m *Migrator) Rollback(ctx context.Context, opts ...MigrationOption) (*MigrationGroup, error) {
 	cfg := newMigrationConfig(opts)
 
@@ -418,7 +457,7 @@ func (m *Migrator) MissingMigrations(ctx context.Context) (MigrationSlice, error
 	return applied, nil
 }
 
-// AppliedMigrations selects applied (applied) migrations in descending order.
+// AppliedMigrations returns applied (applied) migrations in descending order.
 func (m *Migrator) AppliedMigrations(ctx context.Context) (MigrationSlice, error) {
 	var ms MigrationSlice
 	if err := m.db.NewSelect().