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//! Tool Validation and Error Cases Tests
//!
//! Comprehensive tests for tool validation and error handling following TDD principles
use serde_json::json;
use std::time::Duration;
mod mcp_test_helpers;
use mcp_test_helpers::{with_mcp_connection, with_mcp_test_server};
use futures_util::SinkExt;
use tokio_tungstenite::tungstenite::Message;
/// Test 1: RED - Invalid tool argument types
#[tokio::test]
async fn test_invalid_tool_argument_types() {
// Test tools with wrong argument types
with_mcp_connection("invalid_arg_types_test", |_server, mut write, mut read| async move {
let test_cases = vec![
(
json!({
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "echo",
"arguments": 123 // Should be object
}
}),
"Number instead of object for arguments"
),
(
json!({
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "echo",
"arguments": ["array", "args"] // Should be object
}
}),
"Array instead of object for arguments"
),
(
json!({
"jsonrpc": "2.0",
"id": 3,
"method": "tools/call",
"params": {
"name": "echo",
"arguments": null // Null arguments
}
}),
"Null arguments"
),
(
json!({
"jsonrpc": "2.0",
"id": 4,
"method": "tools/call",
"params": {
"name": "echo",
"arguments": {
"message": 123 // Wrong type for message
}
}
}),
"Wrong type for message parameter"
),
];
for (request, description) in test_cases {
write.send(Message::Text(serde_json::to_string(&request)?.into())).await?;
use mcp_test_helpers::receive_ws_message;
let response_text = receive_ws_message(&mut read, Duration::from_secs(5)).await?;
let response: serde_json::Value = serde_json::from_str(&response_text)?;
// Should return error
assert!(
response.get("error").is_some(),
"Expected error for: {}",
description
);
let error = response.get("error").unwrap();
// Should be invalid params error (-32602)
assert_eq!(error["code"], -32602, "Wrong error code for: {}", description);
}
Ok(())
})
.await
.unwrap();
}
/// Test 2: RED - Missing required tool arguments
#[tokio::test]
async fn test_missing_required_arguments() {
// Test tools with missing required arguments
with_mcp_connection("missing_args_test", |_server, mut write, mut read| async move {
let test_cases = vec![
(
json!({
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "echo",
"arguments": {} // Missing message
}
}),
"Missing message for echo"
),
(
json!({
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "read_file",
"arguments": {} // Missing file_path
}
}),
"Missing file_path for read_file"
),
(
json!({
"jsonrpc": "2.0",
"id": 3,
"method": "tools/call",
"params": {
"name": "echo",
"arguments": {
"wrong_param": "value" // Wrong parameter name
}
}
}),
"Wrong parameter name"
),
];
for (request, description) in test_cases {
write.send(Message::Text(serde_json::to_string(&request)?.into())).await?;
use mcp_test_helpers::receive_ws_message;
let response_text = receive_ws_message(&mut read, Duration::from_secs(5)).await?;
let response: serde_json::Value = serde_json::from_str(&response_text)?;
// Should return error
assert!(
response.get("error").is_some(),
"Expected error for: {}",
description
);
}
Ok(())
})
.await
.unwrap();
}
/// Test 3: RED - Tool name validation
#[tokio::test]
async fn test_tool_name_validation() {
// Test various invalid tool names
with_mcp_connection("tool_name_validation_test", |_server, mut write, mut read| async move {
let long_name = "a".repeat(256);
let test_cases = vec![
("", "Empty tool name"),
("tool with spaces", "Tool name with spaces"),
("tool-with-dashes", "Tool name with dashes"),
("UPPERCASE", "Uppercase tool name"),
("123numbers", "Tool name starting with numbers"),
("🚀emoji", "Tool name with emoji"),
("../path/traversal", "Path traversal attempt"),
("tool\0null", "Tool name with null byte"),
(long_name.as_str(), "Very long tool name"),
];
for (tool_name, description) in test_cases {
let request = json!({
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": tool_name,
"arguments": {}
}
});
write.send(Message::Text(serde_json::to_string(&request)?.into())).await?;
use mcp_test_helpers::receive_ws_message;
let response_text = receive_ws_message(&mut read, Duration::from_secs(5)).await?;
let response: serde_json::Value = serde_json::from_str(&response_text)?;
// Should return error for invalid tool names
assert!(
response.get("error").is_some(),
"Expected error for tool name: {}",
description
);
}
Ok(())
})
.await
.unwrap();
}
/// Test 4: RED - Tool execution timeout
#[tokio::test]
async fn test_tool_execution_timeout() {
// Test tool execution that might timeout
with_mcp_connection("tool_timeout_test", |_server, mut write, mut read| async move {
// Create a very large message that might take time to process
let large_message = "x".repeat(1_000_000); // 1MB message
let request = json!({
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "echo",
"arguments": {
"message": large_message
}
}
});
write.send(Message::Text(serde_json::to_string(&request)?.into())).await?;
// Should either complete or timeout gracefully
use mcp_test_helpers::receive_ws_message;
match receive_ws_message(&mut read, Duration::from_secs(10)).await {
Ok(response_text) => {
let response: serde_json::Value = serde_json::from_str(&response_text)?;
// Should have either result or error
assert!(
response.get("result").is_some() || response.get("error").is_some(),
"Response should have result or error"
);
}
Err(_) => {
// Timeout is acceptable for very large messages
assert!(true, "Request timed out as expected");
}
}
Ok(())
})
.await
.unwrap();
}
/// Test 5: RED - Recursive tool calls
#[tokio::test]
async fn test_recursive_tool_calls() {
// Test handling of potentially recursive tool scenarios
with_mcp_connection("recursive_tools_test", |_server, mut write, mut read| async move {
// Try to read a file with a very long path that might cause issues
let recursive_path = "../".repeat(100) + "etc/passwd";
let request = json!({
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "read_file",
"arguments": {
"file_path": recursive_path
}
}
});
write.send(Message::Text(serde_json::to_string(&request)?.into())).await?;
use mcp_test_helpers::receive_ws_message;
let response_text = receive_ws_message(&mut read, Duration::from_secs(5)).await?;
let response: serde_json::Value = serde_json::from_str(&response_text)?;
// Should either fail with error or handle safely
if let Some(_error) = response.get("error") {
assert!(true, "Correctly rejected dangerous path");
} else if let Some(_result) = response.get("result") {
// If it succeeds, it should have handled the path safely
assert!(true, "Handled path safely");
}
Ok(())
})
.await
.unwrap();
}
/// Test 6: RED - Tool argument size limits
#[tokio::test]
async fn test_tool_argument_size_limits() {
// Test tools with extremely large arguments
with_mcp_test_server("arg_size_limits_test", |server| async move {
let client = reqwest::Client::builder()
.timeout(Duration::from_secs(10))
.cookie_store(true)
.build()?;
// Initialize
let init = json!({
"jsonrpc": "2.0",
"id": 1,
"method": "initialize",
"params": {
"protocolVersion": "2025-06-18",
"capabilities": {},
"clientInfo": {"name": "test", "version": "1.0"}
}
});
client.post(&server.http_url()).json(&init).send().await?;
// Test with progressively larger arguments
let sizes = vec![1_000, 10_000, 100_000, 1_000_000, 10_000_000]; // Up to 10MB
for size in sizes {
let large_arg = "x".repeat(size);
let request = json!({
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "echo",
"arguments": {
"message": large_arg
}
}
});
match client.post(&server.http_url()).json(&request).send().await {
Ok(response) => {
if response.status() == 413 {
assert!(true, "Server correctly rejected {} byte payload", size);
break; // No point testing larger sizes
} else if response.status() == 200 {
match response.json::<serde_json::Value>().await {
Ok(body) => {
assert!(
body.get("result").is_some() || body.get("error").is_some(),
"Should have result or error for {} bytes",
size
);
}
Err(_) => {
assert!(true, "Failed to parse large response");
}
}
}
}
Err(_) => {
assert!(true, "Connection failed for {} byte payload", size);
break;
}
}
}
Ok(())
})
.await
.unwrap();
}
/// Test 7: RED - Special characters in tool arguments
#[tokio::test]
async fn test_special_characters_in_arguments() {
// Test handling of special characters in tool arguments
with_mcp_connection("special_chars_test", |_server, mut write, mut read| async move {
let test_cases = vec![
("\n\r\t", "Newlines and tabs"),
("\u{0000}", "Null character"),
("\\\"quotes\\\"", "Escaped quotes"),
("{'json': 'inside'}", "JSON inside string"),
("<script>alert('xss')</script>", "HTML/Script tags"),
("${PATH}", "Shell variable syntax"),
("'; DROP TABLE users; --", "SQL injection attempt"),
("../../../../etc/passwd", "Path traversal"),
("\u{FFFD}\u{FFFE}\u{FFFF}", "Invalid Unicode"),
];
for (special_arg, description) in test_cases {
let request = json!({
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "echo",
"arguments": {
"message": special_arg
}
}
});
write.send(Message::Text(serde_json::to_string(&request)?.into())).await?;
use mcp_test_helpers::receive_ws_message;
let response_text = receive_ws_message(&mut read, Duration::from_secs(5)).await?;
let response: serde_json::Value = serde_json::from_str(&response_text)?;
// Should handle safely - either process or reject
assert!(
response.get("result").is_some() || response.get("error").is_some(),
"Should handle special chars safely for: {}",
description
);
}
Ok(())
})
.await
.unwrap();
}
/// Test 8: RED - Concurrent tool validation
#[tokio::test]
async fn test_concurrent_tool_validation() {
// Test concurrent validation of multiple invalid tool calls
with_mcp_connection("concurrent_validation_test", |_server, mut write, mut read| async move {
// Send multiple invalid requests rapidly
for i in 0..10 {
let request = json!({
"jsonrpc": "2.0",
"id": i,
"method": "tools/call",
"params": {
"name": format!("invalid_tool_{}", i),
"arguments": {}
}
});
write.send(Message::Text(serde_json::to_string(&request)?.into())).await?;
}
// Collect all responses
for i in 0..10 {
use mcp_test_helpers::receive_ws_message;
let response_text = receive_ws_message(&mut read, Duration::from_secs(5)).await?;
let response: serde_json::Value = serde_json::from_str(&response_text)?;
// All should return errors
assert!(response.get("error").is_some(), "Expected error for request {}", i);
assert_eq!(response["id"], i, "Response ID mismatch");
}
Ok(())
})
.await
.unwrap();
}