From 8a2f445c82c290dad11b7e707cd5a6687a969920 Mon Sep 17 00:00:00 2001
From: Yizhou <i@yizhou.ac.cn>
Date: Thu, 22 Jan 2026 14:17:43 +0800
Subject: [PATCH 1/2] test: add MSCV case of compiler toolchain test

---
 tests/unit/Compiler/ToolchainTests.cpp | 36 +++++++++++++++++++++++---
 1 file changed, 33 insertions(+), 3 deletions(-)

diff --git a/tests/unit/Compiler/ToolchainTests.cpp b/tests/unit/Compiler/ToolchainTests.cpp
index 3afcc3739..a638bb50a 100644
--- a/tests/unit/Compiler/ToolchainTests.cpp
+++ b/tests/unit/Compiler/ToolchainTests.cpp
@@ -77,9 +77,39 @@ TEST_CASE(GCC, {.skip = !(CIEnvironment && (Windows || Linux))}) {
     ASSERT_TRUE(unit.diagnostics().empty());
 };
 
-TEST_CASE(MSVC, {.skip = !CIEnvironment}) {
-    // TODO: add MSVC toolchain test when CI provides toolchain.
-}
+TEST_CASE(MSVC, {.skip = !CIEnvironment || !Windows}) {
+    auto file = fs::createTemporaryFile("clice", "cpp");
+    if(!file) {
+        LOG_ERROR_RET(void(), "{}", file.error());
+    }
+
+    llvm::BumpPtrAllocator a;
+    llvm::StringSaver s(a);
+    auto arguments = toolchain::query_toolchain({
+        .arguments = {"cl.exe",
+                      "-std:c++23",
+                      "/EHsc",
+                      file->c_str()},
+        .callback = [&](const char* str) { return s.save(str).data(); }
+    });
+
+    ASSERT_TRUE(arguments.size() > 1);
+
+    CompilationParams params;
+    params.arguments_from_database = true;
+    params.arguments = arguments;
+    params.add_remapped_file(file->c_str(), R"(
+            #include <iostream>
+            int main() {
+                std::cout << "Hello world!" << std::endl;
+                return 0;
+            }
+        )");
+
+    auto unit = compile(params);
+    ASSERT_TRUE(unit.completed());
+    ASSERT_TRUE(unit.diagnostics().empty());
+};
 
 TEST_CASE(Clang, {.skip = !CIEnvironment}) {
     auto file = fs::createTemporaryFile("clice", "cpp");

From 78741beae8b113499e1f00d437605b02f3e335b0 Mon Sep 17 00:00:00 2001
From: Yizhou <i@yizhou.ac.cn>
Date: Thu, 22 Jan 2026 14:45:47 +0800
Subject: [PATCH 2/2] ci: activate MSVC environment

---
 .github/workflows/test-cmake.yml       | 7 +++++++
 tests/unit/Compiler/ToolchainTests.cpp | 5 +++++
 2 files changed, 12 insertions(+)

diff --git a/.github/workflows/test-cmake.yml b/.github/workflows/test-cmake.yml
index 928774029..f95dd33f1 100644
--- a/.github/workflows/test-cmake.yml
+++ b/.github/workflows/test-cmake.yml
@@ -16,10 +16,17 @@ jobs:
           - os: macos-15
             build_type: Debug
     runs-on: ${{ matrix.os }}
+    defaults:
+      run:
+        shell: pwsh
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
 
+      - name: Setup MSVC Developer Environment (Windows)
+        if: matrix.os == 'windows-2025'
+        uses: ilammy/msvc-dev-cmd@v1
+
       - uses: ./.github/actions/setup-pixi
 
       - name: Build
diff --git a/tests/unit/Compiler/ToolchainTests.cpp b/tests/unit/Compiler/ToolchainTests.cpp
index a638bb50a..18d7fe0d7 100644
--- a/tests/unit/Compiler/ToolchainTests.cpp
+++ b/tests/unit/Compiler/ToolchainTests.cpp
@@ -100,6 +100,11 @@ TEST_CASE(MSVC, {.skip = !CIEnvironment || !Windows}) {
     params.arguments = arguments;
     params.add_remapped_file(file->c_str(), R"(
             #include <iostream>
+
+            #if __cplusplus < 202302L
+            #error "C++23 required"
+            #endif
+
             int main() {
                 std::cout << "Hello world!" << std::endl;
                 return 0;