SERVER-27257 Deduplicate symbol `newHarnessHelper`

The `newHarnessHelper` function was defined by multiple test driver
modules, each one specializing it to return a specific kind of
storage test driver's `HarnessHelper`.  The two different kinds
of `HarnessHelper` class were given a common base class, and the
`newHarnessHelper` function was changed to a single implementation.
This new implementation returns the results of a `HarnessHelper`
factory function which can be registered by a MONGO_INITIALIZER
statement.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/mongo/db/storage/sorted_data_interface_test_touch.cpp b/src/mongo/db/storage/sorted_data_interface_test_touch.cpp
index a54fb010832..b83c78fa6f6 100644
--- a/src/mongo/db/storage/sorted_data_interface_test_touch.cpp
+++ b/src/mongo/db/storage/sorted_data_interface_test_touch.cpp
@@ -36,10 +36,11 @@
 #include "mongo/unittest/unittest.h"
 
 namespace mongo {
+namespace {
 
 // Verify that calling touch() on an empty index returns an OK status.
 TEST(SortedDataInterface, TouchEmpty) {
-    const std::unique_ptr<HarnessHelper> harnessHelper(newHarnessHelper());
+    const auto harnessHelper(newSortedDataInterfaceHarnessHelper());
     const std::unique_ptr<SortedDataInterface> sorted(harnessHelper->newSortedDataInterface(false));
 
     {
@@ -51,7 +52,7 @@ TEST(SortedDataInterface, TouchEmpty) {
 
 // Verify that calling touch() on a nonempty index returns an OK status.
 TEST(SortedDataInterface, TouchNonEmpty) {
-    const std::unique_ptr<HarnessHelper> harnessHelper(newHarnessHelper());
+    const auto harnessHelper(newSortedDataInterfaceHarnessHelper());
     const std::unique_ptr<SortedDataInterface> sorted(harnessHelper->newSortedDataInterface(true));
 
     {
@@ -84,4 +85,5 @@ TEST(SortedDataInterface, TouchNonEmpty) {
     }
 }
 
+}  // namespace
 }  // namespace mongo