Unit testing service logic when using - *DB.RunInTx func

[GuyKomari]

I have a service with *bun.DB instance and a method that handles a transaction using RunInTx func.
I would like to add a unit test for this method but in order to do that, I need to use an abstraction over *bun.DB
which seems to be - bun.IDB interface.
However, bun.IDB is missing RunInTx func and other "transaction-related" methods like - BeginTx, Begin, etc.

simple code example:

type MyService struct {
	db            *bun.DB
	myRepo        MyRepo
}

func (s *MyService) DoSmt(ctx context.Context) error {
	err := s.db.RunInTx(ctx, nil, func(ctx context.Context, tx bun.Tx) error {
	        // Get for update
                // Some logic
                // Update
               
               return nil
	})
	
        return err
}

type MyRepo interface { 
     Get(ctx context.Context, db bun.IDB) interface{}, error
     Update(ctx context.Context, db bun.IDB, interface{}) interface{}, error
}

Currently, to overcome this issue, I have created this wrapper that can be used instead of *bun.DB:

type DbWrapper interface {
	bun.IDB
	RunInTx(ctx context.Context, opts *sql.TxOptions, fn func(ctx context.Context, tx bun.Tx) error) error
}

However, it would be nice if it was part of bun.DBI.
Would it be possible to add the "transaction-related" methods to bun.DBI (same as in go-pg)?
Is there a better approach to handle this case?

TIA, Guy

[vmihailenco]

IDB is a common interface for *bun.DB, bun.Conn, and bun.Tx. I don't think we can extend it with Begin and RunInTx.

But we probably can add another interface, for example, ITx in addition to IConn. Then we can probably create ITxDB in addition to IDB. Not sure if it is worth it and makes your task much easier...

[isgj]

Some other ORMs offer the same interface also for the transaction, and when you are already in a tx they use SAVEPOINT.

The bun.Tx can be extended with Begin, RunInTx.. which will work on save-points. In this case the interface IDB can be extended and other than solving this issue it will make it possible for bun.DB and bun.Tx to be used interchangeably (helpful in some scenarios).

[vmihailenco]

@isgj yes, that is an option too. If there is any interest, please send a PR.