Function TestStreamableMcpHeaderVersionGating

mcp/streamable_test.go:2122–2171

TestStreamableMcpHeaderVersionGating verifies that header validation is skipped for protocol versions older than minVersionForStandardHeaders.

(t *testing.T)

// TestStreamableMcpHeaderVersionGating verifies that header validation
// is skipped for protocol versions older than minVersionForStandardHeaders.
func TestStreamableMcpHeaderVersionGating(t *testing.T) {
	server := NewServer(&Implementation{Name: "testServer", Version: "v1.0.0"}, nil)
	server.AddTool(
		&Tool{Name: "my-tool", InputSchema: &jsonschema.Schema{Type: "object"}},
		func(ctx context.Context, req *CallToolRequest) (*CallToolResult, error) {
			return &CallToolResult{}, nil
		})

	handler := NewStreamableHTTPHandler(func(req *http.Request) *Server { return server }, nil)
	defer handler.closeAll()

	initReq := req(1, methodInitialize, &InitializeParams{ProtocolVersion: protocolVersion20251125})
	initResp := resp(1, &InitializeResult{
		Capabilities: &ServerCapabilities{
			Logging: &LoggingCapabilities{},
			Tools:   &ToolCapabilities{ListChanged: true},
		},
		ProtocolVersion: protocolVersion20251125,
		ServerInfo:      &Implementation{Name: "testServer", Version: "v1.0.0"},
	}, nil)

	testStreamableHandler(t, handler, []streamableRequest{
		{
			method:         "POST",
			messages:       []jsonrpc.Message{initReq},
			wantStatusCode: http.StatusOK,
			wantMessages:   []jsonrpc.Message{initResp},
			wantSessionID:  true,
		},
		{
			method:         "POST",
			headers:        http.Header{protocolVersionHeader: {protocolVersion20251125}},
			messages:       []jsonrpc.Message{req(0, notificationInitialized, &InitializedParams{})},
			wantStatusCode: http.StatusAccepted,
		},
		// Requests with deliberately wrong MCP headers should still succeed
		// because the protocol version is too old for validation.
		{
			method: "POST",
			headers: http.Header{
				protocolVersionHeader: {protocolVersion20251125},
				methodHeader:          {"wrong-method"},
				nameHeader:            {"wrong-name"},
			},
			messages:       []jsonrpc.Message{req(2, "tools/call", &CallToolParams{Name: "my-tool"})},
			wantStatusCode: http.StatusOK,
			wantMessages:   []jsonrpc.Message{resp(2, &CallToolResult{Content: []Content{}}, nil)},
		},
	})
}

// TestStreamable405AllowHeader verifies RFC 9110 §15.5.6 compliance:
// 405 Method Not Allowed responses MUST include an Allow header.