sqlmock is a mock library implementing sql/driver. Which has one and only purpose - to simulate any sql driver behavior in tests, without needing a real database connection. It helps to maintain correct TDD workflow.
NOTE: in v1.2.0 sqlmock.Rows has changed to struct from interface, if you were using any type references to that interface, you will need to switch it to a pointer struct type. Also, sqlmock.Rows were used to implement driver.Rows interface, which was not required or useful for mocking and was removed. Hope it will not cause issues.
I do not have much spare time for this library and willing to transfer the repository ownership to person or an organization motivated to maintain it. Open up a conversation if you are interested. See #230.
go get github.com/DATA-DOG/go-sqlmock
Visit godoc for general examples and public api reference. See .travis.yml for supported go versions. Different use case, is to functionally test with a real database - go-txdb all database related actions are isolated within a single transaction so the database can remain in the same state.
See implementation examples:
package main import ( "database/sql" _ "github.com/go-sql-driver/mysql" ) func recordStats(db *sql.DB, userID, productID int64) (err error) { tx, err := db.Begin() if err != nil { return } defer func() { switch err { case nil: err = tx.Commit() default: tx.Rollback() } }() if _, err = tx.Exec("UPDATE products SET views = views + 1"); err != nil { return } if _, err = tx.Exec("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 := sql.Open("mysql", "root@/blog") if err != nil { panic(err) } defer db.Close() if err = recordStats(db, 1 /*some user id*/, 5 /*some product id*/); err != nil { panic(err) } }
package main import ( "fmt" "testing" "github.com/DATA-DOG/go-sqlmock" ) // a successful case func TestShouldUpdateStats(t *testing.T) { db, mock, err := sqlmock.New() if err != nil { t.Fatalf("an error '%s' was not expected when opening a stub database connection", err) } defer db.Close() mock.ExpectBegin() mock.ExpectExec("UPDATE products").WillReturnResult(sqlmock.NewResult(1, 1)) mock.ExpectExec("INSERT INTO product_viewers").WithArgs(2, 3).WillReturnResult(sqlmock.NewResult(1, 1)) mock.ExpectCommit() // now we execute our method if err = recordStats(db, 2, 3); err != nil { t.Errorf("error was not expected while updating stats: %s", err) } // we make sure that all expectations were met if err := mock.ExpectationsWereMet(); err != nil { t.Errorf("there were unfulfilled expectations: %s", err) } } // a failing test case func TestShouldRollbackStatUpdatesOnFailure(t *testing.T) { db, mock, err := sqlmock.New() if err != nil { t.Fatalf("an error '%s' was not expected when opening a stub database connection", err) } defer db.Close() mock.ExpectBegin() mock.ExpectExec("UPDATE products").WillReturnResult(sqlmock.NewResult(1, 1)) mock.ExpectExec("INSERT INTO product_viewers"). WithArgs(2, 3). WillReturnError(fmt.Errorf("some error")) mock.ExpectRollback() // now we execute our method if err = recordStats(db, 2, 3); err == nil { t.Errorf("was expecting an error, but there was none") } // we make sure that all expectations were met if err := mock.ExpectationsWereMet(); err != nil { t.Errorf("there were unfulfilled expectations: %s", err) } }
There were plenty of requests from users regarding SQL query string validation or different matching option. We have now implemented the QueryMatcher interface, which can be passed through an option when calling sqlmock.New or sqlmock.NewWithDSN.
This now allows to include some library, which would allow for example to parse and validate mysql SQL AST. And create a custom QueryMatcher in order to validate SQL in sophisticated ways.
By default, sqlmock is preserving backward compatibility and default query matcher is sqlmock.QueryMatcherRegexp which uses expected SQL string as a regular expression to match incoming query string. There is an equality matcher: QueryMatcherEqual which will do a full case sensitive match.
In order to customize the QueryMatcher, use the following:
db, mock, err := sqlmock.New(sqlmock.QueryMatcherOption(sqlmock.QueryMatcherEqual))
The query matcher can be fully customized based on user needs. sqlmock will not provide a standard sql parsing matchers, since various drivers may not follow the same SQL standard.
There may be arguments which are of struct type and cannot be compared easily by value like time.Time. In this case sqlmock provides an Argument interface which can be used in more sophisticated matching. Here is a simple example of time argument matching:
type AnyTime struct{} // Match satisfies sqlmock.Argument interface func (a AnyTime) Match(v driver.Value) bool { _, ok := v.(time.Time) return ok } func TestAnyTimeArgument(t *testing.T) { t.Parallel() db, mock, err := sqlmock.New() if err != nil { t.Errorf("an error '%s' was not expected when opening a stub database connection", err) } defer db.Close() mock.ExpectExec("INSERT INTO users"). WithArgs("john", AnyTime{}). WillReturnResult(sqlmock.NewResult(1, 1)) _, err = db.Exec("INSERT INTO users(name, created_at) VALUES (?, ?)", "john", time.Now()) if err != nil { t.Errorf("error '%s' was not expected, while inserting a row", err) } if err := mock.ExpectationsWereMet(); err != nil { t.Errorf("there were unfulfilled expectations: %s", err) } }
It only asserts that argument is of time.Time type.
go test -race
go.mod removed the references and suggestions using gopkg.in.db.Prepare() was not validating expected prepare SQL query. It should still be validated even if Exec or Query is not executed on that prepared statement.Feel free to open a pull request. Note, if you wish to contribute an extension to public (exported methods or types) - please open an issue before, to discuss whether these changes can be accepted. All backward incompatible changes are and will be treated cautiously