| 1 | //! Test-only helpers. Compiled under `#[cfg(all(test, unix))]` only, so |
| 2 | //! nothing here can be reached by a real `codewhale mcp-server` run, and |
| 3 | //! Windows — where the POSIX-sh fixture cannot run and its consumers are |
| 4 | //! `#[cfg(unix)]` — does not compile it as dead code. |
| 5 | |
| 6 | use std::path::{Path, PathBuf}; |
| 7 | |
| 8 | /// A minimal POSIX-sh MCP server used to prove that responses come from a |
| 9 | /// spawned process rather than from an in-process stub. |
| 10 | /// |
| 11 | /// It is written in `sh` rather than Rust or Python so the test depends on |
| 12 | /// nothing beyond the shell every unix CI runner already has. |
| 13 | pub const FAKE_MCP_SERVER_SH: &str = r#"#!/bin/sh |
| 14 | while IFS= read -r line; do |
| 15 | id=$(printf '%s' "$line" | sed -n 's/.*"id":\([0-9][0-9]*\).*/\1/p') |
| 16 | method=$(printf '%s' "$line" | sed -n 's/.*"method":"\([^"]*\)".*/\1/p') |
| 17 | if [ -z "$id" ]; then |
| 18 | continue |
| 19 | fi |
| 20 | case "$method" in |
| 21 | initialize) |
| 22 | printf '{"jsonrpc":"2.0","id":%s,"result":{"protocolVersion":"2024-11-05","capabilities":{"tools":{},"resources":{}},"serverInfo":{"name":"fake-mcp","version":"0"}}}\n' "$id" |
| 23 | ;; |
| 24 | tools/list) |
| 25 | printf '{"jsonrpc":"2.0","id":%s,"result":{"tools":[{"name":"add","description":"add two numbers","inputSchema":{"type":"object","properties":{"a":{"type":"number"},"b":{"type":"number"}},"required":["a","b"]}}]}}\n' "$id" |
| 26 | ;; |
| 27 | tools/call) |
| 28 | name=$(printf '%s' "$line" | sed -n 's/.*"name":"\([^"]*\)".*/\1/p') |
| 29 | if [ "$name" = "add" ]; then |
| 30 | printf '{"jsonrpc":"2.0","id":%s,"result":{"content":[{"type":"text","text":"5"}]}}\n' "$id" |
| 31 | else |
| 32 | printf '{"jsonrpc":"2.0","id":%s,"error":{"code":-32602,"message":"unknown tool: '"$name"'"}}\n' "$id" |
| 33 | fi |
| 34 | ;; |
| 35 | resources/list) |
| 36 | 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' "$id" |
| 37 | ;; |
| 38 | resources/read) |
| 39 | printf '{"jsonrpc":"2.0","id":%s,"result":{"contents":[{"uri":"file:///fake/readme.txt","mimeType":"text/plain","text":"spawned-resource"}]}}\n' "$id" |
| 40 | ;; |
| 41 | *) |
| 42 | printf '{"jsonrpc":"2.0","id":%s,"error":{"code":-32601,"message":"unsupported method"}}\n' "$id" |
| 43 | ;; |
| 44 | esac |
| 45 | done |
| 46 | "#; |
| 47 | |
| 48 | /// Owns a temporary directory holding [`FAKE_MCP_SERVER_SH`], removing it on |
| 49 | /// drop. |
| 50 | pub struct FakeServerScript { |
| 51 | dir: PathBuf, |
| 52 | script: PathBuf, |
| 53 | } |
| 54 | |
| 55 | impl FakeServerScript { |
| 56 | pub fn path(&self) -> &Path { |
| 57 | &self.script |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | impl Drop for FakeServerScript { |
| 62 | fn drop(&mut self) { |
| 63 | let _ = std::fs::remove_dir_all(&self.dir); |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | /// Write the fake server to a unique temp directory and return a guard. |
| 68 | pub fn write_fake_mcp_server(label: &str) -> FakeServerScript { |
| 69 | let dir = std::env::temp_dir().join(format!( |
| 70 | "codewhale-mcp-{label}-{}-{:?}", |
| 71 | std::process::id(), |
| 72 | std::thread::current().id() |
| 73 | )); |
| 74 | std::fs::create_dir_all(&dir).expect("fake MCP server dir"); |
| 75 | let script = dir.join("server.sh"); |
| 76 | std::fs::write(&script, FAKE_MCP_SERVER_SH).expect("write fake MCP server"); |
| 77 | FakeServerScript { dir, script } |
| 78 | } |
| 79 |