test: Add minimal test coverage for CLI transport options

- Add tests for config files with different transport types (stdio, sse, streamable-http)
- Add test for backward compatibility with configs missing type field
- Verify transport and serverUrl options are correctly parsed from config files
- All 36 tests pass

Author: felixweinberger

cli/scripts/cli-tests.js

@@ -120,6 +120,57 @@ try {
 const invalidConfigPath = path.join(TEMP_DIR, "invalid-config.json");
 fs.writeFileSync(invalidConfigPath, '{\n  "mcpServers": {\n    "invalid": {');
 
+// Create config files with different transport types for testing
+const sseConfigPath = path.join(TEMP_DIR, "sse-config.json");
+fs.writeFileSync(sseConfigPath, JSON.stringify({
+  mcpServers: {
+    "test-sse": {
+      type: "sse",
+      url: "http://localhost:3000/sse",
+      note: "Test SSE server"
+    }
+  }
+}, null, 2));
+
+const httpConfigPath = path.join(TEMP_DIR, "http-config.json");
+fs.writeFileSync(httpConfigPath, JSON.stringify({
+  mcpServers: {
+    "test-http": {
+      type: "streamable-http",
+      url: "http://localhost:3000/mcp",
+      note: "Test HTTP server"
+    }
+  }
+}, null, 2));
+
+const stdioConfigPath = path.join(TEMP_DIR, "stdio-config.json");
+fs.writeFileSync(stdioConfigPath, JSON.stringify({
+  mcpServers: {
+    "test-stdio": {
+      type: "stdio",
+      command: "npx",
+      args: ["@modelcontextprotocol/server-everything"],
+      env: {
+        TEST_ENV: "test-value"
+      }
+    }
+  }
+}, null, 2));
+
+// Config without type field (backward compatibility)
+const legacyConfigPath = path.join(TEMP_DIR, "legacy-config.json");
+fs.writeFileSync(legacyConfigPath, JSON.stringify({
+  mcpServers: {
+    "test-legacy": {
+      command: "npx",
+      args: ["@modelcontextprotocol/server-everything"],
+      env: {
+        LEGACY_ENV: "legacy-value"
+      }
+    }
+  }
+}, null, 2));
+
 // Function to run a basic test
 async function runBasicTest(testName, ...args) {
   const outputFile = path.join(
@@ -649,6 +700,56 @@ async function runTests() {
     "debug",
   );
 
+  console.log(
+    `\n${colors.YELLOW}=== Running Config Transport Type Tests ===${colors.NC}`,
+  );
+
+  // Test 25: Config with stdio transport type
+  await runBasicTest(
+    "config_stdio_type",
+    "--config",
+    stdioConfigPath,
+    "--server",
+    "test-stdio",
+    "--cli",
+    "--method",
+    "tools/list",
+  );
+
+  // Test 26: Config with SSE transport type (should pass transport to client)
+  await runBasicTest(
+    "config_sse_type",
+    "--config",
+    sseConfigPath,
+    "--server",
+    "test-sse",
+    "echo",
+    "test",
+  );
+
+  // Test 27: Config with streamable-http transport type
+  await runBasicTest(
+    "config_http_type",
+    "--config",
+    httpConfigPath,
+    "--server",
+    "test-http",
+    "echo",
+    "test",
+  );
+
+  // Test 28: Legacy config without type field (backward compatibility)
+  await runBasicTest(
+    "config_legacy_no_type",
+    "--config",
+    legacyConfigPath,
+    "--server",
+    "test-legacy",
+    "--cli",
+    "--method",
+    "tools/list",
+  );
+
   console.log(
     `\n${colors.YELLOW}=== Running HTTP Transport Tests ===${colors.NC}`,
   );
@@ -668,7 +769,7 @@ async function runTests() {
 
   await new Promise((resolve) => setTimeout(resolve, 3000));
 
-  // Test 25: HTTP transport inferred from URL ending with /mcp
+  // Test 29: HTTP transport inferred from URL ending with /mcp
   await runBasicTest(
     "http_transport_inferred",
     "http://127.0.0.1:3001/mcp",
@@ -677,7 +778,7 @@ async function runTests() {
     "tools/list",
   );
 
-  // Test 26: HTTP transport with explicit --transport http flag
+  // Test 30: HTTP transport with explicit --transport http flag
   await runBasicTest(
     "http_transport_with_explicit_flag",
     "http://127.0.0.1:3001/mcp",
@@ -688,7 +789,7 @@ async function runTests() {
     "tools/list",
   );
 
-  // Test 27: HTTP transport with suffix and --transport http flag
+  // Test 31: HTTP transport with suffix and --transport http flag
   await runBasicTest(
     "http_transport_with_explicit_flag_and_suffix",
     "http://127.0.0.1:3001/mcp",
@@ -699,7 +800,7 @@ async function runTests() {
     "tools/list",
   );
 
-  // Test 28: SSE transport given to HTTP server (should fail)
+  // Test 32: SSE transport given to HTTP server (should fail)
   await runErrorTest(
     "sse_transport_given_to_http_server",
     "http://127.0.0.1:3001",
@@ -710,7 +811,7 @@ async function runTests() {
     "tools/list",
   );
 
-  // Test 29: HTTP transport without URL (should fail)
+  // Test 33: HTTP transport without URL (should fail)
   await runErrorTest(
     "http_transport_without_url",
     "--transport",
@@ -720,7 +821,7 @@ async function runTests() {
     "tools/list",
   );
 
-  // Test 30: SSE transport without URL (should fail)
+  // Test 34: SSE transport without URL (should fail)
   await runErrorTest(
     "sse_transport_without_url",
     "--transport",