dbdog

Cucumber database steps for Go

This module implements database-related step definitions for github.com/cucumber/godog.

Database Configuration

Databases instances should be configured with Manager.Instances.

dbm := dbdog.Manager{}

dbm.Instances = map[string]dbdog.Instance{
    "my_db": {
        Storage: storage,
        Tables: map[string]interface{}{
            "my_table":           new(repository.MyRow),
            "my_another_table":   new(repository.MyAnotherRow),
        },
    },
}

Table Mapper Configuration

Table mapper allows customizing decoding string values from godog table cells into Go row structures and back.

tableMapper := dbdog.NewTableMapper()

// Apply JSON decoding to a particular type.
tableMapper.Decoder.RegisterFunc(func(s string) (interface{}, error) {
    m := repository.Meta{}
    err := json.Unmarshal([]byte(s), &m)
    if err != nil {
        return nil, err
    }
    return m, err
}, repository.Meta{})

// Apply string splitting to github.com/lib/pq.StringArray.
tableMapper.Decoder.RegisterFunc(func(s string) (interface{}, error) {
    return pq.StringArray(strings.Split(s, ",")), nil
}, pq.StringArray{})

// Create database manager with custom mapper.
dbm := dbdog.Manager{
    TableMapper: tableMapper,
}

Step Definitions

Delete all rows from table.

Given there are no rows in table "my_table" of database "my_db"

Populate rows in a database.

And these rows are stored in table "my_table" of database "my_db"
| id | foo   | bar | created_at           | deleted_at           |
| 1  | foo-1 | abc | 2021-01-01T00:00:00Z | NULL                 |
| 2  | foo-1 | def | 2021-01-02T00:00:00Z | 2021-01-03T00:00:00Z |
| 3  | foo-2 | hij | 2021-01-03T00:00:00Z | 2021-01-03T00:00:00Z |

And rows from this file are stored in table "my_table" of database "my_db"
 """
 path/to/rows.csv
 """

Assert rows existence in a database.

For each row in gherkin table database is queried to find a row with WHERE condition that includes provided column values.

If a column has NULL value, it is excluded from WHERE condition.

Column can contain variable (any unique string starting with $ or other prefix configured with Manager.VarPrefix). If variable has not yet been populated, it is excluded from WHERE condition and populated with value received from database. When this variable is used in next steps, it replaces the value of column with value of variable.

Variables can help to assert consistency of dynamic data, for example variable can be populated as ID of one entity and then checked as foreign key value of another entity. This can be especially helpful in cases of UUIDs.

If column value represents JSON array or object it is excluded from WHERE condition, value assertion is done by comparing Go value mapped from database row field with Go value mapped from gherkin table cell.

Then these rows are available in table "my_table" of database "my_db"
| id   | foo   | bar | created_at           | deleted_at           |
| $id1 | foo-1 | abc | 2021-01-01T00:00:00Z | NULL                 |
| $id2 | foo-1 | def | 2021-01-02T00:00:00Z | 2021-01-03T00:00:00Z |
| $id3 | foo-2 | hij | 2021-01-03T00:00:00Z | 2021-01-03T00:00:00Z |

Then rows from this file are available in table "my_table" of database "my_db"
 """
 path/to/rows.csv
 """

It is possible to check table contents exhaustively by adding "only" to step statement. Such assertion will also make sure that total number of rows in database table matches number of rows in gherkin table.

Then only these rows are available in table "my_table" of database "my_db"
| id   | foo   | bar | created_at           | deleted_at           |
| $id1 | foo-1 | abc | 2021-01-01T00:00:00Z | NULL                 |
| $id2 | foo-1 | def | 2021-01-02T00:00:00Z | 2021-01-03T00:00:00Z |
| $id3 | foo-2 | hij | 2021-01-03T00:00:00Z | 2021-01-03T00:00:00Z |

Then only rows from this file are available in table "my_table" of database "my_db"
 """
 path/to/rows.csv
 """

Assert no rows exist in a database.

And no rows are available in table "my_another_table" of database "my_db"

The name of database instance of database "my_db" can be omitted in all steps, in such case "default" will be used from database instance name.