pgxpool.Pool does not implement BeginTxFunc required by pgxmock.PgxPoolIface

[TheGrandmother]

If I try to do something like this:

type Client struct {
    pool pgxmock.PgxPoolIface
}

func NewClient() *Client {
    pgUrl := "......"

    Pool, err := pgxpool.New(context.Background(), pgUrl)
    if err != nil {
        panic(err)
    }
    client := Client{pool}
    return &client
}

I get cannot use Pool (variable of type *pgxpool.Pool) as type pgxmock.PgxPoolIface in struct literal: *pgxpool.Pool does not implement pgxmock.PgxPoolIface (missing BeginTxFunc method)

The interface type provided by this package appears to be out of sync as https://github.com/jackc/pgx/blob/master/pgxpool/pool.go does not implement BeginTxFunc but pgxmock.PgxPoolIface inherits (or whatever it is called) it from pgxmock.pgxIface.

But I don't know, I am probably doing something wrong, I am a very inexperienced developer who is not mentally equipped to write go code.

[pashagolub]

Hello,

what versions of pgx and pgxmock are involved?

Thanks in advance!

[bnelz]

@pashagolub we are having the same issue on v5.1.0 of pgx and v2.3.0 of pgxmock.

[pashagolub]

Thanks. The quick workaround would be to create your own interface. And frankly speaking it's not worth to use pgxmock types and/or structs outside of tests

[pashagolub]

Here is the example of how this should be done in the real life. We define our own interface to use and pgxmock used only in tests.

package main

import (
    "context"

    pgx "github.com/jackc/pgx/v5"
    "github.com/jackc/pgx/v5/pgxpool"
)

type PgxIface interface {
    Begin(context.Context) (pgx.Tx, error)
    Close()
}

func recordStats(db PgxIface, userID, productID int) (err error) {
    tx, err := db.Begin(context.Background())
    if err != nil {
        return
    }

    defer func() {
        switch err {
        case nil:
            err = tx.Commit(context.Background())
        default:
            _ = tx.Rollback(context.Background())
        }
    }()

    if _, err = tx.Exec(context.Background(), "UPDATE products SET views = views + 1"); err != nil {
        return
    }
    if _, err = tx.Exec(context.Background(), "INSERT INTO product_viewers (user_id, product_id) VALUES (?, ?)", userID, productID); err != nil {
        return
    }
    return
}

func main() {
    // @NOTE: the real connection is not required for tests
    db, err := pgxpool.New(context.Background(), "postgres://rolname@hostname/dbname")
    if err != nil {
        panic(err)
    }
    defer db.Close()

    if err = recordStats(db, 1 /*some user id*/, 5 /*some product id*/); err != nil {
        panic(err)
    }
}