[docs] [testing] Follow-up for braket target and minor clean-up (#2448

)

* Update docs to show the `braket` examples
* Remove the unsupported tests (tracked in issue#2325)
* Emacs compatible banner
* Update the C++ tests to reflect appropriate reason for skipping.
(Note that `observe` API is not supported)

---------

Signed-off-by: Pradnya Khalate <[email protected]>

CMakeLists.txt

@@ -93,9 +93,9 @@ if (CUDAQ_ENABLE_REST AND NOT DEFINED CUDAQ_ENABLE_REMOTE_SIM)
   endif()
 endif()
 
-# Enable AWS backends by default.
+# Enable Amazon Braket backends by default.
 if (NOT DEFINED CUDAQ_ENABLE_BRAKET_BACKEND)
-  set(CUDAQ_ENABLE_BRAKET_BACKEND ON CACHE BOOL "Enable building AWS backends.")
+  set(CUDAQ_ENABLE_BRAKET_BACKEND ON CACHE BOOL "Enable building AWS SDK for Amazon Braket backends.")
 endif()
 
 # Generate a CompilationDatabase (compile_commands.json file) for our build,

docs/sphinx/using/examples/hardware_providers.rst

@@ -1,9 +1,25 @@
 Using Quantum Hardware Providers
 -----------------------------------
 
-CUDA-Q contains support for using a set of hardware providers (IonQ, IQM, OQC, ORCA Computing and Quantinuum). 
-For more information about executing quantum kernels on different hardware backends, please take a look
-at :doc:`hardware <../backends/hardware>`.
+CUDA-Q contains support for using a set of hardware providers (Amazon Braket, 
+IonQ, IQM, OQC, ORCA Computing, Quantinuum and QuEra Computing). 
+For more information about executing quantum kernels on different hardware 
+backends, please take a look at :doc:`hardware <../backends/hardware>`.
+
+Amazon Braket
+==================================
+
+The following code illustrates how to run kernels on Amazon Braket's backends.
+
+.. tab:: Python
+
+   .. literalinclude:: ../../targets/python/braket.py
+      :language: python
+
+.. tab:: C++
+
+   .. literalinclude:: ../../targets/cpp/braket.cpp
+      :language: cpp
 
 IonQ
 ==================================

runtime/common/BraketExecutor.h

@@ -1,4 +1,4 @@
-/*******************************************************************************
+/****************************************************************-*- C++ -*-****
  * Copyright (c) 2022 - 2024 NVIDIA Corporation & Affiliates.                  *
  * All rights reserved.                                                        *
  *                                                                             *
@@ -7,27 +7,22 @@
  ******************************************************************************/
 
 #pragma once
+
+#include "common/BraketServerHelper.h"
 #include "common/Executor.h"
 #include "common/FmtCore.h"
+#include "common/Logger.h"
 #include "common/MeasureCounts.h"
 #include "cudaq.h"
-
-#include <chrono>
-#include <iostream>
-
-#include <aws/core/Aws.h>
-
 #include <aws/braket/BraketClient.h>
-#include <aws/s3-crt/S3CrtClient.h>
-#include <aws/sts/STSClient.h>
-
+#include <aws/core/Aws.h>
 #include <aws/core/utils/logging/AWSLogging.h>
 #include <aws/core/utils/logging/ConsoleLogSystem.h>
 #include <aws/core/utils/logging/LogLevel.h>
-
-#include "common/BraketServerHelper.h"
-#include "common/Logger.h"
-
+#include <aws/s3-crt/S3CrtClient.h>
+#include <aws/sts/STSClient.h>
+#include <chrono>
+#include <iostream>
 #include <nlohmann/json.hpp>
 #include <regex>
 #include <string>

runtime/common/BraketServerHelper.h

@@ -1,4 +1,4 @@
-/*******************************************************************************
+/****************************************************************-*- C++ -*-****
  * Copyright (c) 2022 - 2024 NVIDIA Corporation & Affiliates.                  *
  * All rights reserved.                                                        *
  *                                                                             *

unittests/backends/braket/BraketTester.cpp

@@ -25,8 +25,7 @@ bool isValidExpVal(double value) {
 }
 
 CUDAQ_TEST(BraketTester, checkSampleSync) {
-  GTEST_SKIP() << "Fails with: Please make sure all qubits in the qubit "
-                  "register are used for tasks submitted to simulators";
+  GTEST_SKIP() << "Amazon Braket credentials required";
   std::string home = std::getenv("HOME");
   std::string fileName = home + "/FakeCppBraket.config";
   auto backendString =
@@ -68,8 +67,7 @@ CUDAQ_TEST(BraketTester, checkSampleSyncEmulate) {
 }
 
 CUDAQ_TEST(BraketTester, checkSampleAsync) {
-  GTEST_SKIP() << "Fails with: Please make sure all qubits in the qubit "
-                  "register are used for tasks submitted to simulators";
+  GTEST_SKIP() << "Amazon Braket credentials required";
   std::string home = std::getenv("HOME");
   std::string fileName = home + "/FakeCppBraket.config";
   auto backendString = fmt::format(fmt::runtime(backendStringTemplate),
@@ -111,8 +109,8 @@ CUDAQ_TEST(BraketTester, checkSampleAsyncEmulate) {
 }
 
 CUDAQ_TEST(BraketTester, checkSampleAsyncLoadFromFile) {
-  GTEST_SKIP() << "Fails with: Please make sure all qubits in the qubit "
-                  "register are used for tasks submitted to simulators";
+  GTEST_SKIP() << "Fails with: Cannot persist a cudaq::future for a local "
+                  "kernel execution.";
   std::string home = std::getenv("HOME");
   std::string fileName = home + "/FakeCppBraket.config";
   auto backendString = fmt::format(fmt::runtime(backendStringTemplate),
@@ -148,9 +146,7 @@ CUDAQ_TEST(BraketTester, checkSampleAsyncLoadFromFile) {
 }
 
 CUDAQ_TEST(BraketTester, checkObserveSync) {
-  GTEST_SKIP() << "Fails with: Device requires all qubits in the program to be "
-                  "measured. This may be caused by declaring non-contiguous "
-                  "qubits or measuring partial qubits";
+  GTEST_SKIP() << "Fails with: Cannot observe kernel with measures in it";
   std::string home = std::getenv("HOME");
   std::string fileName = home + "/FakeCppBraket.config";
   auto backendString = fmt::format(fmt::runtime(backendStringTemplate),
@@ -164,6 +160,7 @@ CUDAQ_TEST(BraketTester, checkObserveSync) {
   kernel.x(qubit[0]);
   kernel.ry(theta, qubit[1]);
   kernel.x<cudaq::ctrl>(qubit[1], qubit[0]);
+  kernel.mz(qubit);
 
   using namespace cudaq::spin;
   cudaq::spin_op h = 5.907 - 2.1433 * x(0) * x(1) - 2.1433 * y(0) * y(1) +
@@ -232,78 +229,6 @@ CUDAQ_TEST(BraketTester, checkObserveAsync) {
   EXPECT_TRUE(isValidExpVal(result.expectation()));
 }
 
-CUDAQ_TEST(BraketTester, checkObserveAsyncEmulate) {
-  std::string home = std::getenv("HOME");
-  std::string fileName = home + "/FakeCppBraket.config";
-  auto backendString = fmt::format(fmt::runtime(backendStringTemplate),
-                                   mockPort, fileName, machine);
-  backendString =
-      std::regex_replace(backendString, std::regex("false"), "true");
-
-  auto &platform = cudaq::get_platform();
-  platform.setTargetBackend(backendString);
-
-  auto [kernel, theta] = cudaq::make_kernel<double>();
-  auto qubit = kernel.qalloc(2);
-  kernel.x(qubit[0]);
-  kernel.ry(theta, qubit[1]);
-  kernel.x<cudaq::ctrl>(qubit[1], qubit[0]);
-
-  using namespace cudaq::spin;
-  cudaq::spin_op h = 5.907 - 2.1433 * x(0) * x(1) - 2.1433 * y(0) * y(1) +
-                     .21829 * z(0) - 6.125 * z(1);
-  auto future = cudaq::observe_async(100000, 0, kernel, h, .59);
-
-  auto result = future.get();
-  result.dump();
-
-  printf("ENERGY: %lf\n", result.expectation());
-  EXPECT_TRUE(isValidExpVal(result.expectation()));
-}
-
-CUDAQ_TEST(BraketTester, checkObserveAsyncLoadFromFile) {
-  GTEST_SKIP() << "Fails with: Device requires all qubits in the program to be "
-                  "measured. This may be caused by declaring non-contiguous "
-                  "qubits or measuring partial qubits";
-  std::string home = std::getenv("HOME");
-  std::string fileName = home + "/FakeCppBraket.config";
-  auto backendString = fmt::format(fmt::runtime(backendStringTemplate),
-                                   mockPort, fileName, machine);
-
-  auto &platform = cudaq::get_platform();
-  platform.setTargetBackend(backendString);
-
-  auto [kernel, theta] = cudaq::make_kernel<double>();
-  auto qubit = kernel.qalloc(2);
-  kernel.x(qubit[0]);
-  kernel.ry(theta, qubit[1]);
-  kernel.x<cudaq::ctrl>(qubit[1], qubit[0]);
-
-  using namespace cudaq::spin;
-  cudaq::spin_op h = 5.907 - 2.1433 * x(0) * x(1) - 2.1433 * y(0) * y(1) +
-                     .21829 * z(0) - 6.125 * z(1);
-  auto future = cudaq::observe_async(kernel, h, .59);
-
-  {
-    std::ofstream out("saveMeObserve.json");
-    out << future;
-  }
-
-  // Later you can come back and read it in
-  cudaq::async_result<cudaq::observe_result> readIn(&h);
-  std::ifstream in("saveMeObserve.json");
-  in >> readIn;
-
-  // Get the results of the read in future.
-  auto result = readIn.get();
-
-  std::remove("saveMeObserve.json");
-  result.dump();
-
-  printf("ENERGY: %lf\n", result.expectation());
-  EXPECT_TRUE(isValidExpVal(result.expectation()));
-}
-
 int main(int argc, char **argv) {
   std::string home = std::getenv("HOME");
   std::string fileName = home + "/FakeCppBraket.config";