我可以使用另一个软件包_test.go中一个软件包的_test.go文件中定义的测试功能吗？ [重复]

I have a db package. Inside of a db_test.go I define a MemoryDb() function to return an in memory database for testing purposes. I can use MemoryDb() from my db_test.go just fine, but I would also like to use it in some other package, apkg's apkg_test.go. That doesn't seem to work, should it?

apkg_test.go

package apkg                                                                                                                                     

import (                                                                                                                                             
        "db"                                                                                                                                     
        "testing"                                                                                                                                                       
)                                                                                                                                                           

func TestHelloWorld(t *testing.T) {                                                                                                  
        _ = db.MemoryDb()                                                                                                                                
}    

db.go

package db                                                                                                                           

// Db struct                                                                                                                                     
type Db struct {                                                                                                                                                        
} 

db_test.go

package db                                                                                                                           

import "testing"                                                                                                                                 

func TestHelloWorld(t *testing.T) {                                                                                                                         
        _ = MemoryDb()
}

func MemoryDb() Db {
        return Db{}
}

Error that I get

/tmp/go/src/db$ go test
PASS
ok      db      0.008s
/tmp/go/src/db$ cd ../apkg/
/tmp/go/src/apkg$ go test
$ apkg [apkg.test]
./apkg_test.go:9:6: undefined: db.MemoryDb
FAIL    apkg [build failed]

Assuming this is not allowed because it's in a _test in another package, is there any way to reach into another package's _test files from other _test files in other packages? I'd rather factor out the MemoryDb but still keep separate _test.go files in separate packages and keey MemoryDb out of deployed binaries (keep it in a _test.go file).

</div>