Simplify backend mock access for unittests (#1062)

src/data/BackendFactory.h

@@ -55,10 +55,8 @@ make_Backend(util::Config const& config)
         throw std::runtime_error("Invalid database type");
 
     auto const rng = backend->hardFetchLedgerRangeNoThrow();
-    if (rng) {
-        backend->updateRange(rng->minSequence);
-        backend->updateRange(rng->maxSequence);
-    }
+    if (rng)
+        backend->setRange(rng->minSequence, rng->maxSequence);
 
     LOG(log.info()) << "Constructed BackendInterface Successfully";
     return backend;

src/data/BackendInterface.cpp

@@ -270,6 +270,19 @@ BackendInterface::updateRange(uint32_t newMax)
     }
 }
 
+void
+BackendInterface::setRange(uint32_t min, uint32_t max, bool force)
+{
+    std::scoped_lock const lck(rngMtx_);
+
+    if (!force) {
+        ASSERT(min <= max, "Range min must be less than or equal to max");
+        ASSERT(not range.has_value(), "Range was already set");
+    }
+
+    range = {min, max};
+}
+
 LedgerPage
 BackendInterface::fetchLedgerPage(
     std::optional<ripple::uint256> const& cursor,

src/data/BackendInterface.h

@@ -191,6 +191,16 @@ public:
     void
     updateRange(uint32_t newMax);
 
+    /**
+     * @brief Sets the range of sequences that are stored in the DB.
+     *
+     * @param min The new minimum sequence available
+     * @param max The new maximum sequence available
+     * @param force If set to true, the range will be set even if it's already set
+     */
+    void
+    setRange(uint32_t min, uint32_t max, bool force = false);
+
     /**
      * @brief Fetch the fees from a specific ledger sequence.
      *