From f496df8943efbe80b738ce7c5e6e1da5ad0b110a Mon Sep 17 00:00:00 2001
From: Haochen Wang <paulhaochen.wang@mail.utoronto.ca>
Date: Tue, 1 Oct 2024 11:43:47 -0400
Subject: [PATCH] test

---
 .../src/measurements/MeasurementsBase.hpp     |  2 +-
 .../tests/Test_MeasurementsBase.cpp           | 20 +++++++++++++++----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/pennylane_lightning/core/src/measurements/MeasurementsBase.hpp b/pennylane_lightning/core/src/measurements/MeasurementsBase.hpp
index 9c8912d6de..7cd8110f6b 100644
--- a/pennylane_lightning/core/src/measurements/MeasurementsBase.hpp
+++ b/pennylane_lightning/core/src/measurements/MeasurementsBase.hpp
@@ -86,7 +86,7 @@ template <class StateVectorT, class Derived> class MeasurementsBase {
     /**
      * @brief Set the internal random generator to an already existing instance
      *
-     * @param catalyst_rng Seed
+     * @param rng An already existing instance of a random number generator
      */
     void setRNG(std::mt19937 rng) { this->rng = std::move(rng); }
 
diff --git a/pennylane_lightning/core/src/measurements/tests/Test_MeasurementsBase.cpp b/pennylane_lightning/core/src/measurements/tests/Test_MeasurementsBase.cpp
index 674659a9cc..389f16fb36 100644
--- a/pennylane_lightning/core/src/measurements/tests/Test_MeasurementsBase.cpp
+++ b/pennylane_lightning/core/src/measurements/tests/Test_MeasurementsBase.cpp
@@ -20,6 +20,8 @@ using Pennylane::Util::isApproxEqual;
 } // namespace
 /// @endcond
 #include <algorithm>
+#include <optional>
+#include <random>
 #include <string>
 
 #ifdef _ENABLE_PLQUBIT
@@ -1251,7 +1253,9 @@ TEST_CASE("Var Shot- TensorProdObs", "[MeasurementsBase][Observables]") {
         testTensorProdObsVarShot<TestStateVectorBackends>();
     }
 }
-template <typename TypeList> void testSamples() {
+
+template <typename TypeList> void testSamples(
+    const std::optional<std::mt19937>& rng = std::nullopt) {
     if constexpr (!std::is_same_v<TypeList, void>) {
         using StateVectorT = typename TypeList::Type;
         using PrecisionT = typename StateVectorT::PrecisionT;
@@ -1281,7 +1285,8 @@ template <typename TypeList> void testSamples() {
         std::size_t num_qubits = 3;
         std::size_t N = std::pow(2, num_qubits);
         std::size_t num_samples = 100000;
-        auto &&samples = Measurer.generate_samples(num_samples);
+        auto &&samples = rng.has_value() ?
+            Measurer.generate_samples(num_samples, rng.value()) : Measurer.generate_samples(num_samples);
 
         std::vector<std::size_t> counts(N, 0);
         std::vector<std::size_t> samples_decimal(num_samples, 0);
@@ -1307,7 +1312,7 @@ template <typename TypeList> void testSamples() {
             REQUIRE_THAT(probabilities,
                          Catch::Approx(expected_probabilities).margin(.05));
         }
-        testSamples<typename TypeList::Next>();
+        testSamples<typename TypeList::Next>(rng);
     }
 }
 
@@ -1317,6 +1322,13 @@ TEST_CASE("Samples", "[MeasurementsBase]") {
     }
 }
 
+TEST_CASE("Seeded samples", "[MeasurementsBase]") {
+    if constexpr (BACKEND_FOUND) {
+        std::mt19937 rng(37.42);
+        testSamples<TestStateVectorBackends>(rng);
+    }
+}
+
 template <typename TypeList> void testSamplesCountsObs() {
     if constexpr (!std::is_same_v<TypeList, void>) {
         using StateVectorT = typename TypeList::Type;
@@ -1729,4 +1741,4 @@ TEST_CASE("Measure Shot - SparseHObs ", "[MeasurementsBase][Observables]") {
     if constexpr (BACKEND_FOUND) {
         testSparseHObsMeasureShot<TestStateVectorBackends>();
     }
-}
\ No newline at end of file
+}