模拟QLDB操作的指南或示例&交易

Question

我目前正在编写一个应用程序，该应用程序正在写入QLDB账本。我有一个类似的功能：

// Use an interface that matches the QLDB Driver so we can inject / mock
type ILedgerDriver interface {
Execute(ctx context.Context, fn func(txn qldbdriver.Transaction) (interface{}, error)) (interface{}, error)
Shutdown(ctx context.Context)
}
// Create checks for a records existence before inserting on to the ledger.
func Create(driver ILedgerDriver, document interface{}) (interface{}, error) {
return ls.Driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) {
result, err := txn.Execute("SELECT * FROM People WHERE ID = ?", id)
if err != nil {
return nil, errors.Wrap(err, "error selecting document")
}
// Check if there are any results
if result.Next(txn) {
// document exists
return nil, nil
}
result, err = txn.Execute("INSERT INTO People ?", document)
if err != nil {
return nil, errors.Wrap(err, "error inserting document")
}
return result, nil
})
}

然后我试着用这样的东西来嘲笑：

// implements qldbdriver.Transaction.
type mockQldbTx struct{}
func (mockQldbTx) Execute(statement string, parameters ...interface{}) (*qldbdriver.Result, error) {
for _, p := range parameters {
if ps, _ := p.(string); ps == "ERROR" {
return nil, errors.New("execute failed")
}
if ps, _ := p.(string); ps == "WILLFINDME" {
emptyResult := &qldbdriver.Result{}
return emptyResult, nil
}
}
return nil, nil
}
func (mockQldbTx) BufferResult(result *qldbdriver.Result) (*qldbdriver.BufferedResult, error) {
return nil, nil
}
func (mockQldbTx) Abort() error {
return nil
}
// implements ILedgerDriver
type mockDriver struct{}
func (mockDriver) Execute(ctx context.Context, fn func(txn qldbdriver.Transaction) (interface{}, error)) (interface{}, error) {
mockTx1 := mockQldbTx{}
result, err := fn(mockTx1)
return result, err
}
func (mockDriver) Shutdown(ctx context.Context) {
}

这在很大程度上是有效的。然而，由于qldbdriver.Result不是一个接口，当结果具有index和pageValues属性(这将触发if result.Next(txn)块(时，我似乎无法模拟事务来测试这种情况。

有没有人对此有任何经验，或者可以向任何导游介绍？还是我真的有点过于谨慎了，我真的不需要测试我的create函数是否有效？(除此之外，任何其他更大的业务逻辑都将在另一个可以单独测试的功能中？(

Answer 1

在QLDB驱动程序的最新提交中，QLDB团队引入了Result接口来解决您遇到的问题。请参阅解决此问题的此提交。

复制自该期的指南：下面是一个简化的代码片段，显示了传递到Execute的函数的测试。Transaction和Result现在是接口，mockTransaction和mockResult在我们的测试场景中实现。

// Your upsert method that can be passed into QLDBDriver.Execute()
func upsert(txn Transaction) (interface{}, error) {
res, _ := txn.Execute("SELECT * FROM Table WHERE ID = '12345'")
if res.Next(txn) {
txn.Execute("UPDATE Table SET Name = 'Foo' WHERE ID = '12345'")
} else {
txn.Execute("INSERT INTO Person <<{'Name' : 'Foo', 'ID' : '12345'}>>")
}
return nil, nil
}
type mockTransaction struct {
mock.Mock
}
func (m *mockTransaction) Execute(statement string, parameters ...interface{}) (Result, error) {
args := m.Called(statement, parameters)
return args.Get(0).(Result), args.Error(1)
}
func (m *mockTransaction) BufferResult(res Result) (BufferedResult, error) {
panic("not used")
}
func (m *mockTransaction) Abort() error {
panic("not used")
}
type mockResult struct {
mock.Mock
}
func (r *mockResult) Next(txn Transaction) bool {
args := r.Called(txn)
return args.Get(0).(bool)
}
func (r *mockResult) GetCurrentData() []byte {
panic("not used")
}
func (r *mockResult) GetConsumedIOs() *IOUsage {
panic("not used")
}
func (r *mockResult) GetTimingInformation() *TimingInformation {
panic("not used")
}
func (r *mockResult) Err() error {
panic("not used")
}
func TestUpsert(t *testing.T) {
// Document already exists (update)
mockTxn := new(mockTransaction)
mockRes := new(mockResult)
mockRes.On("Next", mockTxn).Return(true).Once()
mockTxn.On("Execute", "SELECT * FROM Table WHERE ID = '12345'", mock.Anything).Return(mockRes, nil)
mockTxn.On("Execute", "UPDATE Table SET Name = 'Foo' WHERE ID = '12345'", mock.Anything).Return(mockRes, nil)
upsert(mockTxn)
mockTxn.AssertCalled(t,"Execute", "UPDATE Table SET Name = 'Foo' WHERE ID = '12345'", mock.Anything)
mockTxn.AssertNotCalled(t,"Execute", "INSERT INTO Person <<{'Name' : 'Foo', 'ID' : '12345'}>>", mock.Anything)
// Document did not exist (insert)
mockRes.On("Next", mockTxn).Return(false).Once()
mockTxn.On("Execute", "INSERT INTO Person <<{'Name' : 'Foo', 'ID' : '12345'}>>", mock.Anything).Return(mockRes, nil)
upsert(mockTxn)
mockTxn.AssertCalled(t,"Execute", "INSERT INTO Person <<{'Name' : 'Foo', 'ID' : '12345'}>>", mock.Anything)
}

这还没有发布，所以如果你能够根据最新的代码进行构建，那就太好了，否则我们(我为QLDB工作(可以组织一次正式发布。