我在测试运行时遇到以下 panic :

panic: sql: connection returned that was never out

测试

实际测试是test suite的一部分, 并定义为:

func (suite *RowsSuite) TestReadFrom_SanityTest() {
    t := suite.T()

    rows := new(sql.Rows)
    *rows = suite.nonEmptyRows

    assert.True(t, rows.Next())
    // hit the function like it's supposed to be hit
    err := ReadFrom(rows,
        suite.fnStubFalse,
        suite.spots[0],
        suite.spots[1],
        suite.spots[2])

    // There better be no error
    if !assert.Nil(t, err) {
        t.Error(err.ToString(false))
    }

}

被测代码

我负责测试这个功能:

// ReadFrom reads values from `rows` into `valuePlaceholders`
func ReadFrom(rows *sql.Rows,
    readerFunc func(rowIndex int, readValues ...interface{}) (bool, *errors.ErrorSt),
    valuePlaceholders ...interface{}) (err *errors.ErrorSt) {

    rowLine := 1
    for rows.Next() {
        if err := rows.Scan(valuePlaceholders...); err != nil {
            return errors.Database().AddDetails(err.Error(), valuePlaceholders)
        }
        if readerFunc != nil {
            skipRest, err := readerFunc(rowLine, valuePlaceholders...)
            if err != nil {
                return err
            }
            if skipRest {
                break
            }
        }
        rowLine++
    }
    if rowLine == 1 {
        return errors.Get(appErrors.ACNoRows)
    }
    return nil
}

设置

suite.fnStubFalse 只是一个返回 false,nil 的函数 stub suite.spots 只是一个大小为 3 的 []*interface{}。简单地说，它是要扫描 的三个点。

与测试相关的其余定义在套件设置时调用的辅助方法中定义:

func (suite *RowsSuite) setupRowStates() {
    // for throwing fatal error right away
    t := suite.T()
    // fire up the mock
    suite.db, suite.mock, suite.err = sqlmock.New()
    // if there's an error, fatally throw it right away!
    if !assert.Nilf(t,
        suite.err,
        "Error with initializing a stub database connection") {
        t.Fatal()
    }

    // define the possible expectant result sets
    noRows := sqlmock.NewRows(suite.columns)
    nonEmptyRows := sqlmock.NewRows(suite.columns).
        AddRow(381, "Beans", 1.59).
        AddRow(34981, "Frozen Pizza", 5.49)

    // define our sql behavior
    regex := "^SELECT (.+) FROM items$"
    sql := "SELECT (item_id, item_name, item_price) FROM items"

    specificRegex := "^SELECT (.+) FROM items (.+)$"
    specificSQL := `
    SELECT (item_id, item_name, item_price) FROM items i
    INNER JOIN stock s
    ON s.item_id = i.item_id
    WHERE TIME_TO_SEC(s.stock_time) > TIME_TO_SEC(NOW())`

    // setup general query to return non-empty rows
    suite.mock.ExpectQuery(regex).
        WillReturnRows(nonEmptyRows)
    // setup specific query to return empty rows
    suite.mock.ExpectQuery(specificRegex).
        WillReturnRows(noRows)

    // hit both queries right now and store the state of their
    //  return values, terminating right away on any errors
    var err error
    rows, err := suite.db.Query(sql)
    if err != nil {
        t.Fatal(err.Error())
    }
    suite.nonEmptyRows = *rows
    emptyRows, err := suite.db.Query(specificSQL)
    if err != nil {
        t.Fatal(err.Error())
    }
    suite.noRows = *emptyRows

}

完整错误

这个怪物:

Running tool: C:\Go\bin\go.exe test -timeout 30s ezsoft\apiserver_sdk\db -run ^TestRowsSuite$

panic: sql: connection returned that was never out

goroutine 22 [running]:
database/sql.(*DB).putConn(0xc04204d400, 0xc04212a080, 0x0, 0x0, 0xc04213de01)
    C:/Go/src/database/sql/sql.go:1158 +0x351
database/sql.(*driverConn).releaseConn(0xc04212a080, 0x0, 0x0)
    C:/Go/src/database/sql/sql.go:383 +0x53
database/sql.(*driverConn).(database/sql.releaseConn)-fm(0x0, 0x0)
    C:/Go/src/database/sql/sql.go:706 +0x45
database/sql.(*Rows).close(0xc04212a100, 0x899be0, 0xc042048380, 0x0, 0x0)
    C:/Go/src/database/sql/sql.go:2932 +0x159
database/sql.(*Rows).awaitDone(0xc04212a100, 0x89d260, 0xc042050b00, 0x0, 0x0)
    C:/Go/src/database/sql/sql.go:2588 +0x12f
created by database/sql.(*Rows).initContextClose
    C:/Go/src/database/sql/sql.go:2572 +0xa3
FAIL    ezsoft/apiserver_sdk/db 0.429s
Error: Tests failed.

使用的第三方库

我使用 testify和 go-sqlmock (我可能会搬起石头砸自己的脚，用它来简单地 stub 查询，因为我不得不跳过设置中的环节。)

我不知道是什么导致了这次失败。 当我删除测试并运行套件本身时，一切正常

最佳答案

事实证明我对这种情况想得太多了。

我通过将两个行状态存储为指针，然后在 RowsSuite.SetupTest 中设置它们(在测试级别，而不是套件级别)来修复它。从那里，我只需获取测试中的一个状态，就可以开始了。即，而不是这个(在 C++ 中可以正常工作):

func (suite *RowsSuite) TestReadFrom_SanityTest() {
    t := suite.T()

    rows := new(sql.Rows)
    *rows = suite.nonEmptyRows

    assert.True(t, rows.Next())
    // hit the function like it's supposed to be hit
    err := ReadFrom(rows,
        suite.fnStubFalse,
        suite.spots[0],
        suite.spots[1],
        suite.spots[2])

    // There better be no error
    if !assert.Nil(t, err) {
        t.Error(err.ToString(false))
    }

}

我是这样做的:

func (suite *RowsSuite) TestReadFrom_SanityTest() {
    t := suite.T()

    rows := suite.nonEmptyRows

    // hit the function like it's supposed to be hit
    errSt := ReadFrom(rows,
        suite.fnStubFalse,
        suite.spots[0],
        suite.spots[1],
        suite.spots[2])

    // There better be no error
    if !assert.Nil(t, errSt) {
        t.Error(errSt.ToString(false))
    }

}

其中 nonEmptyRows 是测试运行前设置的状态之一

关于unit-testing - 来自测试， panic : sql: connection returned that was never out，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/52081995/