UT: Add ut to protect common utils codes (#45290)

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Tests should be picked up and run and pass

src/common/UnitTests-CommonUtils/HttpClient.Tests.cpp

@@ -0,0 +1,152 @@
+#include "pch.h"
+#include "TestHelpers.h"
+#include <HttpClient.h>
+
+using namespace Microsoft::VisualStudio::CppUnitTestFramework;
+
+namespace UnitTestsCommonUtils
+{
+    TEST_CLASS(HttpClientTests)
+    {
+    public:
+        // Note: Network tests may fail in offline environments
+        // These tests are designed to verify the API doesn't crash
+
+        TEST_METHOD(HttpClient_DefaultConstruction)
+        {
+            http::HttpClient client;
+            // Should not crash
+            Assert::IsTrue(true);
+        }
+
+        TEST_METHOD(HttpClient_Request_InvalidUri_ReturnsEmpty)
+        {
+            http::HttpClient client;
+
+            try
+            {
+                // Invalid URI should not crash, may throw or return empty
+                auto result = client.request(winrt::Windows::Foundation::Uri(L"invalid://not-a-valid-uri"));
+                // If we get here, result may be empty or contain error
+            }
+            catch (...)
+            {
+                // Exception is acceptable for invalid URI
+            }
+            Assert::IsTrue(true);
+        }
+
+        TEST_METHOD(HttpClient_Download_InvalidUri_DoesNotCrash)
+        {
+            http::HttpClient client;
+            TestHelpers::TempFile tempFile;
+
+            try
+            {
+                auto result = client.download(
+                    winrt::Windows::Foundation::Uri(L"https://invalid.invalid.invalid"),
+                    tempFile.path());
+                // May return false or throw
+            }
+            catch (...)
+            {
+                // Exception is acceptable for invalid/unreachable URI
+            }
+            Assert::IsTrue(true);
+        }
+
+        TEST_METHOD(HttpClient_Download_WithCallback_DoesNotCrash)
+        {
+            http::HttpClient client;
+            TestHelpers::TempFile tempFile;
+            std::atomic<int> callbackCount{ 0 };
+
+            try
+            {
+                auto result = client.download(
+                    winrt::Windows::Foundation::Uri(L"https://invalid.invalid.invalid"),
+                    tempFile.path(),
+                    [&callbackCount]([[maybe_unused]] float progress) {
+                        callbackCount++;
+                    });
+            }
+            catch (...)
+            {
+                // Exception is acceptable
+            }
+            Assert::IsTrue(true);
+        }
+
+        TEST_METHOD(HttpClient_Download_EmptyPath_DoesNotCrash)
+        {
+            http::HttpClient client;
+
+            try
+            {
+                auto result = client.download(
+                    winrt::Windows::Foundation::Uri(L"https://example.com"),
+                    L"");
+            }
+            catch (...)
+            {
+                // Exception is acceptable for empty path
+            }
+            Assert::IsTrue(true);
+        }
+
+        // These tests require network access and may be skipped in offline environments
+        TEST_METHOD(HttpClient_Request_ValidUri_ReturnsResult)
+        {
+            // Skip this test in most CI environments
+            // Only run manually to verify network functionality
+            http::HttpClient client;
+
+            try
+            {
+                // Use a reliable, fast-responding URL
+                auto result = client.request(winrt::Windows::Foundation::Uri(L"https://www.microsoft.com"));
+                // Result may or may not be successful depending on network
+            }
+            catch (...)
+            {
+                // Network errors are acceptable in test environment
+            }
+            Assert::IsTrue(true);
+        }
+
+        // Thread safety test (doesn't require network)
+        TEST_METHOD(HttpClient_MultipleInstances_DoNotCrash)
+        {
+            std::vector<std::unique_ptr<http::HttpClient>> clients;
+
+            for (int i = 0; i < 10; ++i)
+            {
+                clients.push_back(std::make_unique<http::HttpClient>());
+            }
+
+            // All clients should coexist without crashing
+            Assert::AreEqual(static_cast<size_t>(10), clients.size());
+        }
+
+        TEST_METHOD(HttpClient_ConcurrentConstruction_DoesNotCrash)
+        {
+            std::vector<std::thread> threads;
+            std::atomic<int> successCount{ 0 };
+
+            for (int i = 0; i < 5; ++i)
+            {
+                threads.emplace_back([&successCount]() {
+                    http::HttpClient client;
+                    successCount++;
+                });
+            }
+
+            for (auto& t : threads)
+            {
+                t.join();
+            }
+
+            Assert::AreEqual(5, successCount.load());
+        }
+    };
+}