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我目前正在编写一个正在写入 QLDB 分类帐的应用程序。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
    })
}

然后我尝试用这样的东西来模拟：

// 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) {
}

这在很大程度上有效。但是，由于qldbdriver.Result不是接口，因此我似乎无法模拟事务来测试结果何时具有index和pageValues属性（这将触发if result.Next(txn)块）的情况。

任何人都有这方面的经验或可以指出任何指南？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？（除此之外的任何其他更大的业务逻辑都在另一个可以单独测试的函数中？）

4

1 回答 1

0

在对 QLDB 驱动程序的最新提交中，QLDB 团队介绍了Result解决您遇到的问题的接口。请参阅解决此问题的此提交。

复制该问题中的指南：下面是一个简化的代码片段，显示了对传递给的函数的测试Execute。Transaction现在Result是接口，在我们的测试场景中实现mockTransaction。mockResult

// 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，所以如果你能够针对最新的代码进行构建，那就太好了，否则我们（我为 QLDB 工作）可以组织正式发布。

于 2021-04-20T21:51:08.930 回答