feat: Add clangd integration tests and documentation (#29)

Author: Shamazo

.github/workflows/go.yml

@@ -131,3 +131,39 @@ jobs:
 
       - name: Run TypeScript integration tests
         run: go test ./integrationtests/tests/typescript/...
+
+  clangd-integration-tests:
+    name: Clangd Integration Tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.24"
+          check-latest: true
+          cache: true
+
+      - name: Install LLVM, Clang and bear
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y clang-16 llvm-16 clangd-16 bear
+
+      - name: Verify Clangd Installation
+        run: |
+          sudo ln -s /usr/bin/clangd-16 /usr/bin/clangd
+          clangd-16 --version
+          clangd --version
+      
+      - name: Create compile commands
+        run: |
+          cd integrationtests/workspaces/clangd
+          bear -- make
+          cd ../../../..
+
+      - name: Run Clangd definition tests
+        run: go test ./integrationtests/tests/clangd/definition...
+
+      - name: Run Clangd diagnostics tests
+        run: go test ./integrationtests/tests/clangd/diagnostics...

.gitignore

@@ -4,6 +4,12 @@ mcp-language-server
 # Test output
 test-output/
 *.diff
+integrationtests/workspaces/clangd/compile_commands.json
+integrationtests/workspaces/clangd/src/*.o
+integrationtests/workspaces/clangd/clean_program
+integrationtests/workspaces/clangd/program
+integrationtests/workspaces/clangd/.cache
+
 
 # Temporary files
 *~

README.md

@@ -124,6 +124,37 @@ This is an [MCP](https://modelcontextprotocol.io/introduction) server that runs
 </pre>
   </div>
 </details>
+<details>
+  <summary>C/C++ (clangd)</summary>
+  <div>
+    <p><strong>Install clangd</strong>: Download prebuilt binaries from the <a href="https://github.com/clangd/clangd/releases">official LLVM releases page</a> or install via your system's package manager (e.g., <code>apt install clangd</code>, <code>brew install clangd</code>).</p>
+    <p><strong>Configure your MCP client</strong>: This will be different but similar for each client. For Claude Desktop, add the following to <code>~/Library/Application\\ Support/Claude/claude_desktop_config.json</code></p>
+
+<pre>
+{
+  "mcpServers": {
+    "language-server": {
+      "command": "mcp-language-server",
+      "args": [
+        "--workspace",
+        "/Users/you/dev/yourproject/",
+        "--lsp",
+        "/path/to/your/clangd_binary",
+        "--",
+        "--compile-commands-dir=/path/to/yourproject/build_or_compile_commands_dir"
+      ]
+    }
+  }
+}
+</pre>
+    <p><strong>Note</strong>:</p>
+    <ul>
+      <li>Replace <code>/path/to/your/clangd_binary</code> with the actual path to your clangd executable.</li>
+      <li><code>--compile-commands-dir</code> should point to the directory containing your <code>compile_commands.json</code> file (e.g., <code>./build</code>, <code>./cmake-build-debug</code>).</li>
+      <li>Ensure <code>compile_commands.json</code> is generated for your project for clangd to work effectively.</li>
+    </ul>
+  </div>
+</details>
 <details>
   <summary>Other</summary>
   <div>

integrationtests/snapshots/clangd/definition/class.snap

@@ -0,0 +1,16 @@
+---
+
+Symbol: TestClass
+/TEST_OUTPUT/workspace/clangd/src/consumer.cpp
+Range: L7:C1 - L15:C2
+
+ 7|class TestClass {
+ 8| public:
+ 9|  /**
+10|   * @brief A method that takes an integer parameter.
+11|   *
+12|   * @param param The integer parameter to be processed.
+13|   */
+14|  void method(int param) { helperFunction(); }
+15|};
+

integrationtests/snapshots/clangd/definition/constant.snap

@@ -0,0 +1,8 @@
+---
+
+Symbol: TEST_CONSTANT
+/TEST_OUTPUT/workspace/clangd/src/helper.cpp
+Range: L4:C1 - L4:C29
+
+4|const int TEST_CONSTANT = 42;
+

integrationtests/snapshots/clangd/definition/foobar.snap

@@ -0,0 +1,11 @@
+---
+
+Symbol: foo_bar
+/TEST_OUTPUT/workspace/src/main.cpp
+Range: L5:C1 - L8:C2
+
+5|void foo_bar() {
+6|  std::cout << "Hello, World!" << std::endl;
+7|  return;
+8|}
+

integrationtests/snapshots/clangd/definition/helperFunction.snap

@@ -0,0 +1,8 @@
+---
+
+Symbol: helperFunction
+/TEST_OUTPUT/workspace/clangd/src/helper.cpp
+Range: L7:C1 - L7:C71
+
+7|void helperFunction() { std::cout << "Helper function" << std::endl; }
+

integrationtests/snapshots/clangd/definition/method.snap

@@ -0,0 +1,16 @@
+---
+
+Symbol: method
+/TEST_OUTPUT/workspace/clangd/src/consumer.cpp
+Range: L7:C1 - L15:C2
+
+ 7|class TestClass {
+ 8| public:
+ 9|  /**
+10|   * @brief A method that takes an integer parameter.
+11|   *
+12|   * @param param The integer parameter to be processed.
+13|   */
+14|  void method(int param) { helperFunction(); }
+15|};
+

integrationtests/snapshots/clangd/definition/struct.snap

@@ -0,0 +1,10 @@
+---
+
+Symbol: TestStruct
+/TEST_OUTPUT/workspace/clangd/src/types.cpp
+Range: L6:C1 - L8:C2
+
+6|struct TestStruct {
+7|  int value;
+8|};
+

integrationtests/snapshots/clangd/definition/type.snap

@@ -0,0 +1,8 @@
+---
+
+Symbol: TestType
+/TEST_OUTPUT/workspace/clangd/src/types.cpp
+Range: L10:C1 - L10:C21
+
+10|using TestType = int;
+