Add integration test suite

Author: isaacphi

.github/dependabot.yml

@@ -0,0 +1,19 @@
+version: 2
+updates:
+  - package-ecosystem: "gomod"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    open-pull-requests-limit: 10
+    labels:
+      - "dependencies"
+      - "go"
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    open-pull-requests-limit: 10
+    labels:
+      - "dependencies"
+      - "github-actions"

.github/workflows/go.yml

@@ -0,0 +1,53 @@
+name: CI Workflow
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
+
+jobs:
+  test:
+    name: Run 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 gopls
+        run: go install golang.org/x/tools/gopls@latest
+
+      - name: Run tests
+        run: go test ./...
+
+  check:
+    name: Build and Code Quality Checks
+    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: Build
+        run: go build -o mcp-language-server
+
+      - name: Install just
+        run: curl --proto '=https' --tlsv1.2 -sSf https://just.systems/install.sh | bash -s -- --to /usr/local/bin
+
+      - name: Install gopls
+        run: go install golang.org/x/tools/gopls@latest
+
+      - name: Run code quality checks
+        run: just check

.gitignore

@@ -1,5 +1,11 @@
 # Binary
 mcp-language-server
 
+# Test output
+test-output/
+*.diff
+
 # Temporary files
 *~
+
+CLAUDE.md

ATTRIBUTION

@@ -4,7 +4,7 @@ This project includes code derived from the following third-party sources:
 
 ## Go Tools LSP Protocol Generator
 
-The code in `cmd/generate_protocol/` includes modified code from the Go Tools project's LSP protocol implementation.
+The code in `cmd/generate/` includes modified code from the Go Tools project's LSP protocol implementation.
 
 - **Source**: https://go.googlesource.com/tools
 - **License**: BSD 3-Clause

README.md

@@ -1,5 +1,10 @@
 # MCP Language Server
 
+[![Go Tests](https://github.com/isaacphi/mcp-language-server/actions/workflows/go.yml/badge.svg)](https://github.com/isaacphi/mcp-language-server/actions/workflows/go.yml)
+[![Go Report Card](https://goreportcard.com/badge/github.com/isaacphi/mcp-language-server)](https://goreportcard.com/report/github.com/isaacphi/mcp-language-server)
+[![GoDoc](https://pkg.go.dev/badge/github.com/isaacphi/mcp-language-server)](https://pkg.go.dev/github.com/isaacphi/mcp-language-server)
+[![Go Version](https://img.shields.io/github/go-mod/go-version/isaacphi/mcp-language-server)](https://github.com/isaacphi/mcp-language-server/blob/main/go.mod)
+
 A Model Context Protocol (MCP) server that runs a language server and provides tools for communicating with it.
 
 ## Motivation
@@ -78,7 +83,7 @@ Add something like the following configuration to your Claude Desktop settings (
         "--stdio"
       ],
       "env": {
-        "DEBUG": "1"
+        "LOG_LEVEL": "INFO"
       }
     }
   }
@@ -91,7 +96,7 @@ Replace:
 - `/opt/homebrew/bin/pyright-langserver` with the path to your language server (found using `which` command e.g. `which pyright-langserver`)
 - Any aruments after `--` are sent as arguments to your language server.
 - Any env variables are passed on to the language server. Some may be necessary for you language server. For example, `gopls` required `GOPATH` and `GOCACHE` in order for me to get it working properly.
-- `DEBUG=1` is optional. See below.
+- `LOG_LEVEL` is optional. See below.
 
 ## Development
 
@@ -114,6 +119,18 @@ Build:
 go build
 ```
 
+Run tests:
+
+```bash
+go test ./...
+```
+
+Update test snapshots:
+
+```bash
+UPDATE_SNAPSHOTS=true go test ./integrationtests/...
+```
+
 Configure your Claude Desktop (or similar) to use the local binary:
 
 ```json
@@ -128,7 +145,7 @@ Configure your Claude Desktop (or similar) to use the local binary:
         "/path/to/language/server"
       ],
       "env": {
-        "DEBUG": "1"
+        "LOG_LEVEL": "DEBUG"
       }
     }
   }
@@ -143,11 +160,12 @@ Include
 
 ```
 env: {
-  "DEBUG": 1
+  "LOG_LEVEL": "DEBUG",
+  "LOG_COMPONENT_LEVELS": "wire:DEBUG"
 }
 ```
 
-To get detailed LSP and application logs. Please include as much information as possible when opening issues.
+To get detailed LSP and application logs. Setting `LOG_LEVEL` to DEBUG enables verbose logging for all components. Adding `LOG_COMPONENT_LEVELS` with `wire:DEBUG` shows raw LSP JSON messages. Please include as much information as possible when opening issues.
 
 The following features are on my radar:
 
@@ -162,3 +180,4 @@ The following features are on my radar:
 - [ ] Add LSP server configuration options and presets for common languages
 - [ ] Make a more consistent and scalable API for tools (pagination, etc.)
 - [ ] Create tools at a higher level of abstraction, combining diagnostics, code lens, hover, and code actions when reading definitions or references.
+

cmd/generate/generate.go

@@ -35,7 +35,7 @@ func generateDoc(out *bytes.Buffer, doc string) {
 		return
 	}
 	var list bool
-	for _, line := range strings.Split(doc, "\n") {
+	for _, line := range strings.SplitN(doc, "\n", -1) {
 		// Lists in metaModel.json start with a dash.
 		// To make a go doc list they have to be preceded
 		// by a blank line, and indented.

cmd/generate/main.go

@@ -57,7 +57,11 @@ func processinline() {
 		if err != nil {
 			log.Fatal(err)
 		}
-		defer os.RemoveAll(tmpdir) // ignore error
+		defer func() {
+			if err := os.RemoveAll(tmpdir); err != nil {
+				log.Printf("Failed to remove temporary directory: %v", err)
+			}
+		}()
 
 		// Clone the repository.
 		cmd := exec.Command("git", "clone", "--quiet", "--depth=1", "-c", "advice.detachedHead=false", vscodeRepo, "--branch="+lspGitRef, "--single-branch", tmpdir)
@@ -268,7 +272,7 @@ func (t *Type) UnmarshalJSON(data []byte) error {
 			Value *Type `json:"value"`
 		}
 		if err := json.Unmarshal(data, &x); err != nil {
-			return fmt.Errorf("Type.kind=map: %v", err)
+			return fmt.Errorf("Type.kind=map: %v", err) //lint:ignore ST1005 ignore
 		}
 		t.Key = x.Key
 		t.Value = x.Value
@@ -279,7 +283,7 @@ func (t *Type) UnmarshalJSON(data []byte) error {
 		}
 
 		if err := json.Unmarshal(data, &z); err != nil {
-			return fmt.Errorf("Type.kind=literal: %v", err)
+			return fmt.Errorf("Type.kind=literal: %v", err) //lint:ignore ST1005 ignore
 		}
 		t.Value = z.Value
 

cmd/generate/main_test.go

@@ -40,7 +40,7 @@ func TestParseContents(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	var our interface{}
+	var our any
 	if err := json.Unmarshal(out, &our); err != nil {
 		t.Fatal(err)
 	}
@@ -50,7 +50,7 @@ func TestParseContents(t *testing.T) {
 	if err != nil {
 		t.Fatalf("could not read metaModel.json: %v", err)
 	}
-	var raw interface{}
+	var raw any
 	if err := json.Unmarshal(buf, &raw); err != nil {
 		t.Fatal(err)
 	}

cmd/generate/methods.go

@@ -51,8 +51,7 @@ func generateMethodForRequest(out *bytes.Buffer, r *Request) {
 	// Generate doc comment
 	fmt.Fprintf(out, "\n// %s\n", methodName+" sends a "+r.Method+" request to the LSP server.")
 	if r.Documentation != "" {
-		docLines := strings.Split(cleanDocComment(r.Documentation), "\n")
-		for _, line := range docLines {
+		for _, line := range strings.SplitN(cleanDocComment(r.Documentation), "\n", -1) {
 			fmt.Fprintf(out, "// %s\n", line)
 		}
 	}
@@ -110,8 +109,7 @@ func generateMethodForNotification(out *bytes.Buffer, n *Notification) {
 	// Generate doc comment
 	fmt.Fprintf(out, "\n// %s\n", methodName+" sends a "+n.Method+" notification to the LSP server.")
 	if n.Documentation != "" {
-		docLines := strings.Split(cleanDocComment(n.Documentation), "\n")
-		for _, line := range docLines {
+		for _, line := range strings.SplitN(cleanDocComment(n.Documentation), "\n", -1) {
 			fmt.Fprintf(out, "// %s\n", line)
 		}
 	}

cmd/generate/output.go

@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"fmt"
 	"log"
+	"slices"
 	"sort"
 	"strings"
 )
@@ -220,7 +221,7 @@ func genStructs(model *Model) {
 		out.WriteString(lspLink(model, camelCase(s.Name)))
 		fmt.Fprintf(out, "type %s struct {%s\n", nm, linex(s.Line))
 		// for gpls compatibilitye, embed most extensions, but expand the rest some day
-		props := append([]NameType{}, s.Properties...)
+		props := slices.Clone(s.Properties)
 		if s.Name == "SymbolInformation" { // but expand this one
 			for _, ex := range s.Extends {
 				fmt.Fprintf(out, "\t// extends %s\n", ex.Name)