Add CppModulesProject test scenario for C++20 modules groundwork

.github/workflows/job-compile-and-test.yml

@@ -106,6 +106,11 @@ jobs:
         run: yarn test --scenario=SimpleCppProject
         working-directory: Extension
 
+      - name: Run CppModulesProject tests (Windows)
+        if: ${{ inputs.platform == 'windows' }}
+        run: yarn test --scenario=CppModulesProject
+        working-directory: Extension
+
       - name: Run E2E IntelliSense features tests (Windows)
         if: ${{ inputs.platform == 'windows' }}
         run: yarn test --scenario=MultirootDeadlockTest

Extension/test/scenarios/CppModulesProject/assets/.gitignore

@@ -0,0 +1,3 @@
+# Generated at runtime by the scenario tests.
+.vscode/
+build/

Extension/test/scenarios/CppModulesProject/assets/main.cpp

@@ -0,0 +1,27 @@
+// Module importer used by the compile_commands.json based tests.
+//
+// Diagnostics on the import statements are expected until IntelliSense
+// support for C++20 modules is available for all compilers
+// (https://github.com/microsoft/vscode-cpptools/issues/6302).
+
+import math;
+import geometry;
+
+// Sentinel probe: this define is only provided by the compile_commands.json
+// entry for this file. The test hovers on the use of the symbol below to
+// verify that the compilation database entry -- including its module related
+// flags -- was actually applied to this translation unit, rather than
+// IntelliSense falling back to a default configuration.
+#ifdef CPPMODULES_COMPILE_COMMANDS_SENTINEL
+int compile_database_sentinel_value = 1;
+#endif
+
+int probe_compile_database()
+{
+    return compile_database_sentinel_value;
+}
+
+int main()
+{
+    return add(1, 2) + square_area(3) - math::k_answer;
+}

Extension/test/scenarios/CppModulesProject/assets/main2.cpp

@@ -0,0 +1,23 @@
+// Module importer used by the custom configuration provider tests
+// (GCC-style module compiler arguments).
+
+import math;
+import geometry;
+
+// Sentinel probe: this define is only provided through the compilerArgs of the
+// custom configuration provider used by the tests. The hover assertion proves
+// that the provider's arguments (which also carry the GCC module flags) were
+// delivered to the language server for this translation unit.
+#ifdef PROVIDER_GCC_SENTINEL
+int provider_gcc_sentinel_value = 1;
+#endif
+
+int probe_provider_gcc()
+{
+    return provider_gcc_sentinel_value;
+}
+
+int main()
+{
+    return add(2, 3) + square_area(4) - math::k_answer;
+}

Extension/test/scenarios/CppModulesProject/assets/main3.cpp

@@ -0,0 +1,23 @@
+// Module importer used by the custom configuration provider tests
+// (MSVC-style module compiler arguments).
+
+import math;
+import geometry;
+
+// Sentinel probe: this define is only provided through the compilerArgs of the
+// custom configuration provider used by the tests. The hover assertion proves
+// that the provider's arguments (which also carry the MSVC module arguments)
+// were delivered to the language server for this translation unit.
+#ifdef PROVIDER_MSVC_SENTINEL
+int provider_msvc_sentinel_value = 1;
+#endif
+
+int probe_provider_msvc()
+{
+    return provider_msvc_sentinel_value;
+}
+
+int main()
+{
+    return add(3, 4) + square_area(5) - math::k_answer;
+}

Extension/test/scenarios/CppModulesProject/assets/math.cppm

@@ -0,0 +1,24 @@
+// Module interface unit using the GCC-style file extension (.cppm).
+//
+// IntelliSense support for C++20 modules is tracked at
+// https://github.com/microsoft/vscode-cpptools/issues/6302. These sources are
+// used by the CppModulesProject scenario tests to cover the extension-side
+// behavior that module based projects rely on.
+
+export module math;
+
+export int add(int a, int b)
+{
+    return a + b;
+}
+
+export namespace math
+{
+    constexpr int k_answer = 42;
+}
+
+// Not exported; part of the module implementation only.
+int implementation_detail()
+{
+    return math::k_answer;
+}

Extension/test/scenarios/CppModulesProject/assets/math.ixx

@@ -0,0 +1,13 @@
+// Module interface unit using the MSVC-style file extension (.ixx).
+//
+// IntelliSense support for C++20 modules is tracked at
+// https://github.com/microsoft/vscode-cpptools/issues/6302. These sources are
+// used by the CppModulesProject scenario tests to cover the extension-side
+// behavior that module based projects rely on.
+
+export module geometry;
+
+export int square_area(int side)
+{
+    return side * side;
+}