#![cfg(unix)]
use std::fs;
use std::io::Write;
use std::path::PathBuf;
use std::process::{Command, Stdio};
use serde_json::{Value, json};
use tempfile::TempDir;
const FAKE_SERVER: &str = r#"#!/bin/sh
while IFS= read -r line; do
id=$(printf '%s' "$line" | sed -n 's/.*"id":\([0-9][0-9]*\).*/\1/p')
method=$(printf '%s' "$line" | sed -n 's/.*"method":"\([^"]*\)".*/\1/p')
if [ -z "$id" ]; then
continue
fi
case "$method" in
initialize)
printf '{"jsonrpc":"2.0","id":%s,"result":{"protocolVersion":"2024-11-05","capabilities":{"tools":{},"resources":{}},"serverInfo":{"name":"fake-mcp","version":"0"}}}\n' "$id"
;;
tools/list)
printf '{"jsonrpc":"2.0","id":%s,"result":{"tools":[{"name":"whoami","description":"report the spawned process","inputSchema":{"type":"object","properties":{}}}]}}\n' "$id"
;;
tools/call)
printf '{"jsonrpc":"2.0","id":%s,"result":{"content":[{"type":"text","text":"spawned-child"}]}}\n' "$id"
;;
resources/list)
printf '{"jsonrpc":"2.0","id":%s,"result":{"resources":[{"uri":"file:///fake/readme.txt","name":"Fake readme","description":"resource from the spawned process","mimeType":"text/plain","size":16,"annotations":{"audience":["assistant"],"priority":0.75}}]}}\n' "$id"
;;
resources/read)
printf '{"jsonrpc":"2.0","id":%s,"result":{"contents":[{"uri":"file:///fake/readme.txt","mimeType":"text/plain","text":"spawned-resource"}]}}\n' "$id"
;;
*)
printf '{"jsonrpc":"2.0","id":%s,"error":{"code":-32601,"message":"unsupported method"}}\n' "$id"
;;
esac
done
"#;
struct Fixture {
_root: TempDir,
home: PathBuf,
}
impl Fixture {
fn new() -> Self {
let root = TempDir::new().expect("fixture root");
let home = root.path().join("sealed-home");
fs::create_dir_all(home.join(".codewhale")).expect("sealed config dir");
fs::write(home.join(".codewhale").join("config.toml"), "").expect("seed config");
Self { _root: root, home }
}
fn command(&self) -> Command {
let mut command = Command::new(codewhale_binary());
command
.env_clear()
.env("PATH", std::env::var("PATH").unwrap_or_default())
.env("HOME", &self.home)
.env("USERPROFILE", &self.home)
.env("CODEWHALE_HOME", self.home.join(".codewhale"))
.env("CODEWHALE_SECRET_BACKEND", "file");
command
}
fn write_fake_server(&self) -> PathBuf {
let script = self.home.join("fake-mcp-server.sh");
fs::write(&script, FAKE_SERVER).expect("write fake MCP server");
script
}
fn configure_servers(&self, definitions: Value) {
let output = self
.command()
.args(["config", "set", "mcp.server_definitions"])
.arg(definitions.to_string())
.output()
.expect("run config set");
assert!(
output.status.success(),
"config set failed\nstdout:\n{}\nstderr:\n{}",
String::from_utf8_lossy(&output.stdout),
String::from_utf8_lossy(&output.stderr)
);
}
fn run_mcp_server(&self, requests: &[Value]) -> (Vec<Value>, String) {
let mut child = self
.command()
.arg("mcp-server")
.stdin(Stdio::piped())
.stdout(Stdio::piped())
.stderr(Stdio::piped())
.spawn()
.expect("spawn codewhale mcp-server");
{
let stdin = child.stdin.as_mut().expect("mcp-server stdin");
for request in requests {
writeln!(stdin, "{request}").expect("write request");
}
}
let output = child.wait_with_output().expect("mcp-server output");
let stderr = String::from_utf8_lossy(&output.stderr).to_string();
let responses = String::from_utf8_lossy(&output.stdout)
.lines()
.filter_map(|line| serde_json::from_str::<Value>(line).ok())
.collect();
(responses, stderr)
}
}
fn codewhale_binary() -> PathBuf {
if let Some(path) = option_env!("CARGO_BIN_EXE_codewhale") {
return PathBuf::from(path);
}
if let Ok(path) = std::env::var("CARGO_BIN_EXE_codewhale") {
return PathBuf::from(path);
}
let mut path = std::env::current_exe().expect("current test executable path");
path.pop();
if path.ends_with("deps") {
path.pop();
}
path.join("codewhale")
}
fn response_for(responses: &[Value], id: i64) -> &Value {
responses
.iter()
.find(|response| response["id"] == json!(id))
.unwrap_or_else(|| panic!("no response with id {id} in {responses:?}"))
}
#[test]
fn mcp_server_enforces_jsonrpc_identity_and_initialize_lifecycle() {
let fixture = Fixture::new();
let (responses, stderr) = fixture.run_mcp_server(&[
json!({"id": 1, "method": "ping"}),
json!({"jsonrpc": "2.0", "id": null, "method": "ping"}),
json!({"jsonrpc": "2", "id": 2, "method": "ping"}),
json!({"jsonrpc": "2.0", "id": 3, "method": "tools/list"}),
json!({
"jsonrpc": "2.0",
"id": 4,
"method": "initialize",
"params": {
"protocolVersion": "2024-11-05",
"clientInfo": {"name": "lifecycle-test", "version": "1"},
"capabilities": {}
}
}),
json!({"jsonrpc": "2.0", "id": 5, "method": "resources/list"}),
json!({"jsonrpc": "2.0", "method": "notifications/initialized"}),
json!({"jsonrpc": "2.0", "method": "ping"}),
json!({"jsonrpc": "2.0", "id": 6, "method": "tools/list"}),
json!({"jsonrpc": "2.0", "id": 7, "method": "shutdown"}),
]);
let null_id_responses: Vec<&Value> = responses
.iter()
.filter(|response| response["id"].is_null())
.collect();
assert_eq!(
null_id_responses.len(),
2,
"missing id must be a notification while explicit null receives a response: {responses:?}"
);
assert_eq!(null_id_responses[0]["error"]["code"], -32600);
assert!(null_id_responses[1]["result"].is_object());
assert_eq!(response_for(&responses, 2)["error"]["code"], -32600);
assert_eq!(response_for(&responses, 3)["error"]["code"], -32600);
assert!(
response_for(&responses, 3)["error"]["message"]
.as_str()
.is_some_and(|message| message.contains("completed initialize"))
);
assert_eq!(
response_for(&responses, 4)["result"]["protocolVersion"],
"2024-11-05"
);
assert_eq!(response_for(&responses, 5)["error"]["code"], -32600);
assert_eq!(response_for(&responses, 6)["result"]["tools"], json!([]));
assert!(
stderr.contains("codewhale mcp-server: stdio server exited"),
"missing clean shutdown receipt:\n{stderr}"
);
}
#[test]
fn mcp_server_proxies_tools_and_resources_from_the_configured_child_process() {
let fixture = Fixture::new();
let script = fixture.write_fake_server();
fixture.configure_servers(json!([{
"config": {
"name": "fake",
"command": "/bin/sh",
"args": [script.to_str().expect("utf-8 script path")],
}
}]));
let (responses, stderr) = fixture.run_mcp_server(&[
json!({
"jsonrpc": "2.0",
"id": 0,
"method": "initialize",
"params": {
"protocolVersion": "2024-11-05",
"clientInfo": {"name": "proxy-test", "version": "1"},
"capabilities": {}
}
}),
json!({"jsonrpc": "2.0", "method": "notifications/initialized"}),
json!({"jsonrpc": "2.0", "id": 1, "method": "tools/list"}),
json!({
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {"name": "mcp__fake__whoami", "arguments": {}}
}),
json!({"jsonrpc": "2.0", "id": 3, "method": "resources/list"}),
json!({
"jsonrpc": "2.0",
"id": 4,
"method": "resources/read",
"params": {"uri": "file:///fake/readme.txt"}
}),
json!({"jsonrpc": "2.0", "id": 5, "method": "shutdown"}),
]);
let initialize = response_for(&responses, 0);
assert_eq!(initialize["result"]["protocolVersion"], "2024-11-05");
assert_eq!(
initialize["result"]["serverInfo"]["name"],
"codewhale-mcp-server"
);
assert!(initialize["result"]["capabilities"]["tools"].is_object());
assert!(initialize["result"]["capabilities"]["resources"].is_object());
let tools = response_for(&responses, 1)["result"]["tools"]
.as_array()
.unwrap_or_else(|| panic!("tools/list returned no array; stderr:\n{stderr}"))
.clone();
let names: Vec<&str> = tools
.iter()
.filter_map(|tool| tool["name"].as_str())
.collect();
assert_eq!(
names,
vec!["mcp__fake__whoami"],
"only the child's real tools may be exposed; the stub's fabricated \
`health`/`capabilities` must be gone. stderr:\n{stderr}"
);
assert_eq!(tools[0]["tool_name"], "whoami");
assert!(tools[0]["inputSchema"].is_object());
let call = response_for(&responses, 2);
assert_eq!(
call["result"]["content"][0]["text"], "spawned-child",
"the standard MCP result must come from the spawned process: {call}"
);
assert_eq!(
call["result"]["result"]["content"][0]["text"], "spawned-child",
"the legacy nested result must remain available: {call}"
);
let resources = response_for(&responses, 3)["result"]["resources"]
.as_array()
.unwrap_or_else(|| panic!("resources/list returned no array; stderr:\n{stderr}"));
assert_eq!(resources.len(), 1);
assert_eq!(resources[0]["uri"], "file:///fake/readme.txt");
assert_eq!(resources[0]["name"], "Fake readme");
assert_eq!(resources[0]["mimeType"], "text/plain");
assert_eq!(resources[0]["size"], 16);
assert_eq!(
resources[0]["annotations"]["audience"],
json!(["assistant"])
);
assert_eq!(resources[0]["annotations"]["priority"], 0.75);
assert_eq!(resources[0]["server_name"], "fake");
let read = response_for(&responses, 4);
assert_eq!(read["result"]["contents"][0]["text"], "spawned-resource");
assert_eq!(
read["result"]["resource"]["contents"][0]["text"], "spawned-resource",
"the legacy nested resource must remain available: {read}"
);
assert!(
!stderr.contains("deepseek-mcp"),
"stale identity in stderr:\n{stderr}"
);
assert!(
stderr.contains("codewhale mcp-server: stdio server exited"),
"missing Codewhale shutdown identity in stderr:\n{stderr}"
);
}
#[test]
fn mcp_server_reports_a_server_it_could_not_spawn() {
let fixture = Fixture::new();
fixture.configure_servers(json!([{
"config": {
"name": "broken",
"command": "codewhale-nonexistent-mcp-server-binary",
}
}]));
let (responses, stderr) = fixture.run_mcp_server(&[
json!({"jsonrpc": "2.0", "id": 1, "method": "server/list"}),
json!({
"jsonrpc": "2.0",
"id": 10,
"method": "initialize",
"params": {
"protocolVersion": "2024-11-05",
"clientInfo": {"name": "failure-test", "version": "1"},
"capabilities": {}
}
}),
json!({"jsonrpc": "2.0", "method": "notifications/initialized"}),
json!({
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {"name": "mcp__broken__health", "arguments": {}}
}),
json!({"jsonrpc": "2.0", "id": 3, "method": "shutdown"}),
]);
let server = response_for(&responses, 1)["result"]["lifecycle"]["servers"][0].clone();
assert_eq!(
server["running"],
json!(false),
"an unspawnable server must not report as running: {server}"
);
assert!(
server["error"]
.as_str()
.is_some_and(|error| error.contains("failed to spawn command")),
"the lifecycle must carry the spawn failure: {server}"
);
assert!(
stderr.contains("is not available"),
"the failure must also be loud on stderr, got:\n{stderr}"
);
let call = response_for(&responses, 2);
assert!(
call["error"].is_object(),
"a dead server must return an error, never a fabricated success: {call}"
);
}