dbcontext

dbcontext

Nestable transaction-like contexts for Go database/sql database connections. Primarily made for writing integration tests - run each test inside a TxContext, and have the application code start/rollback/commit subcontexts when it would usually use transactions.

Known issues

• Currently only tested with MySQL
  • Uses savepoints, which are available in Postgres. Shouldn't be too hard to also test Postgres.
• API is currently unstable
• Contexts aren't concurrency-safe - you should only have one active SavepointContext in a TxContext at any given time. The contexts should make up a stack, and there should only be one context at any given level in the stack.
  • Database transactions aren't really concurrency-safe either, so this shouldn't be a surprise

Usage

First, install the library

go get git.sr.ht/~pmc/dbcontext

Then, use it. Check out the tests for some more examples. Here's a psuedocode example:

// In your tests:
func TestMyApp(t *testing.T) {
  db, err := sql.Open("mysql", "")
  require.NoError(t, err)
  dbcontext.WithTxContext(db, func(context *dbcontext.TxContext) (*any, error) {
    httpRequest(db, "POST", "/user/{user_id}", myUserData)
    // Do whatever testing you need here
    // WithTxContext will automatically rollback the transaction if it hasn't already been rolled back or committed
    return nil, nil
  })
}

// In your application
func PostUserHandler(db dbcontext.SqlContext, req HttpRequest) (*HttpResponse, error) {
  return dbcontext.WithSubcontext(db, func(tx dbcontext.SqlContext) (*HttpResponse, error) {
    var user User
    row := tx.QueryRow("SELECT * FROM users WHERE user_id = ?", req.UserID)
    if row.Err() != nil {
      return nil, row.Err()
    }
    err := row.Scan(&user)
    if err != nil {
      return nil, err
    }
    return &HttpResponse{
      User: user,
    }, nil
  })
}

Blue Oak Model License

Version 1.0.0

Purpose

This license gives everyone as much permission to work with this software as possible, while protecting contributors from liability.

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Copyright

Each contributor licenses you to do everything with this software that would otherwise infringe that contributor's copyright in it.

Notices

You must ensure that everyone who gets a copy of any part of this software from you, with or without changes, also gets the text of this license or a link to https://blueoakcouncil.org/license/1.0.0.

Excuse

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Patent

Each contributor licenses you to do everything with this software that would otherwise infringe any patent claims they can license or become able to license.

Reliability

No contributor can revoke this license.

No Liability

As far as the law allows, this software comes as is, without any warranty or condition, and no contributor will be liable to anyone for any damages related to this software or this license, under any kind of legal claim.