The testutils package provides a mock database to replace the go-pg/v9 database client in tests and includes mock transactions.

In order to use the testutils.MockDB type in tests, the functions expecting the database client as a parameter should use the testutils.DB interface instead of *pg.DB. The application should pass a testutils.DBWrapper reference to these functions, which wraps pg.DB to implement the testutils.DB interface. Tests for these methods will pass a testutils.MockDB reference. The testutils.DB and testutils.Tx interfaces implement common methods used from the pg.DB and pg.Tx types.

To use a type with the mock database types, the type must implement the testutils.Model interface. The required functions may be defined in the test file(s) for the type, and need not appear in the application code.

(*pg.DB) RunInTransaction (func (*pg.Tx) error) error method calls will need to be updated to pass a function with signature (func (testutils.Tx) error). Use of the DB interface is otherwise the same.

The Model interface must be implemented by types inserted, updated, and deleted from the mock database. It allows the mock database to find a "matching" record without a SQL parser (and becoming something too similar to a real database, which exceeds the intent of this package).

GetID should return a string that represents a unique identifier for this type. In most cases, it may be the primary key cast to a string.

Equals returns whether or not the receiver and passed variable match for all important fields. Some fields cannot be known (for example, created and modified timestamps) and should not be compared for equality in this function. It mainly serves two uses: to check if the receiver matches an empty struct and to see if the receiver matches all important fields in a struct of the same type that represents the expected value. It should return false if the type of the passed value and the receiver do not match.

go-pg's DB type includes pg.BaseDB by composition, so it is included here, but no matching mock type is implemented. The testutils.DB interface includes these and the testutils.MockDB type implements these methods directly.

RunInTransaction runs a function in a transaction. If function returns an error transaction is rollbacked, otherwise transaction is committed.

Query executes a query that returns rows, typically a SELECT. The params are for any placeholders in the query.

QueryOne acts like Query, but query must return only one row. It returns ErrNoRows error when query returns zero rows or ErrMultiRows when query returns multiple rows.

The testutils.DB interface includes the testutils.BaseDB interface.

Query is an alias for DB.Query

QueryOne is an alias for DB.QueryOne

Select is an alias for DB.Select

Insert is an alias for DB.Insert

Update is an alias for DB.Update

Delete is an alias for DB.Delete

NewMockDB creates a new mock database client of unit tests.

QueueResponses inserts data of any type into the mock database. Data will be returned, one value at a time, to the Query, QueryOne, and Select functions in the order it was inserted without any attempt to parse the query or match conditions or IDs. Data inserted into QueueResponses does not need to implement the testutils.Model interface.

QueueModels inserts structs into the mock database without using MockDB.Insert to set up a test including Update or Delete calls. Values passed to QueueModels must implement the testutils.Model interface.

Find returns the value in the mock database models that matches the type and ID of the provided model if it exists and nil if it doesn't.

MarshalModels returns an indented string of JSON for logging out the contents of the MockDB models. It isn't useful for automated tests, but can give the developer a way to see what data has been stored.

MarshalResponses returns an indented string of JSON for logging out the contents of the MockDB models. It isn't useful for automated tests, but can give the developer a way to see what data has queued for response.

Diff compares two values of the same type. If they are different types, an error is returned. If they are the same type, it returns a map of names of field struct fields that did not match as keys and a slice containing the unequal field values as values