persistence/client/factory.go test coverage (#5859)

Our ability to cover this file is rather harshly limited due to it directly calling funcs in other packages that try to make network connections... but thankfully the DataStore-based stuff can be intercepted.  So I've at least tested those branches.

More generally this package is yet another strong argument in favor of leaning more on go.uber.org/fx for dependency injection.  Very little of this has to be (or should be) hard-coded in this file.  It feels like Java's "Service Locator" pattern, but even worse because the language doesn't allow test controls of globals like Java does... so I doubt it's a coincidence that there's a `bean.go` file in here.

common/log/testlogger/testlogger.go

@@ -23,9 +23,6 @@
 package testlogger
 
 import (
-	"testing"
-
-	"github.com/stretchr/testify/require"
 	"go.uber.org/zap/zaptest"
 
 	"github.com/uber/cadence/common/log"
@@ -34,11 +31,6 @@ import (
 
 // New is a helper to create new development logger in unit test
 func New(t zaptest.TestingT) log.Logger {
-	if testing.Verbose() {
-		logger, err := loggerimpl.NewDevelopment()
-		require.NoError(t, err)
-		return logger
-	}
-	// test logger samples all logs
+	// test logger that emits all logs (none dropped / sample func never returns false)
 	return loggerimpl.NewLogger(zaptest.NewLogger(t), loggerimpl.WithSampleFunc(func(int) bool { return true }))
 }

common/persistence/client/factory.go

@@ -18,6 +18,8 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
+//go:generate mockgen -package $GOPACKAGE -source $GOFILE -destination factory_mock.go
+
 package client
 
 import (