fn_registry/cpp/tests/test_http_get_json.cpp

// test_http_get_json.cpp — Catch2 integration tests for fn_http::get_json.
// Issue 0110. Uses the same Python HTTP fixture as test_http_request.cpp but
// scoped locally to keep tests independent (each binary owns its own server).
#include "catch_amalgamated.hpp"
#include "core/http_get_json.h"
#include "core/http_request.h"
#include "nlohmann/json.hpp"

#include <chrono>
#include <cstdio>
#include <cstdlib>
#include <fstream>
#include <string>
#include <thread>

#ifndef _WIN32
#include <signal.h>
#include <sys/wait.h>
#include <unistd.h>
#endif

namespace {

constexpr const char* kHost = "127.0.0.1";

int pick_port() {
    return 47300 + (int)(getpid() % 100);
}

struct PythonServer {
    pid_t pid = 0;
    int   port = 0;

    bool start() {
        port = pick_port();
        std::string script_path = std::tmpnam(nullptr);
        script_path += ".py";
        {
            std::ofstream f(script_path);
            f <<
                "import json, sys\n"
                "from http.server import BaseHTTPRequestHandler, HTTPServer\n"
                "PORT = int(sys.argv[1])\n"
                "class H(BaseHTTPRequestHandler):\n"
                "    def log_message(self, *a, **k): pass\n"
                "    def do_GET(self):\n"
                "        if self.path.startswith('/status/'):\n"
                "            code = int(self.path.rsplit('/',1)[1])\n"
                "            msg = ('error %d' % code).encode()\n"
                "            self.send_response(code); self.send_header('content-length',str(len(msg))); self.end_headers(); self.wfile.write(msg); return\n"
                "        if self.path == '/notjson':\n"
                "            self.send_response(200); self.send_header('content-type','text/plain'); self.end_headers(); self.wfile.write(b'<<not json>>'); return\n"
                "        payload = {\n"
                "            'ok':True,\n"
                "            'path':self.path,\n"
                "            'auth':self.headers.get('Authorization','')\n"
                "        }\n"
                "        out = json.dumps(payload).encode()\n"
                "        self.send_response(200); self.send_header('content-type','application/json'); self.send_header('content-length',str(len(out))); self.end_headers(); self.wfile.write(out)\n"
                "HTTPServer(('127.0.0.1', PORT), H).serve_forever()\n";
        }

#ifdef _WIN32
        return false;
#else
        pid_t p = fork();
        if (p < 0) return false;
        if (p == 0) {
            FILE* dn = std::freopen("/dev/null", "r", stdin);  (void)dn;
            FILE* d2 = std::freopen("/dev/null", "w", stdout); (void)d2;
            FILE* d3 = std::freopen("/dev/null", "w", stderr); (void)d3;
            execlp("python3", "python3", "-u", script_path.c_str(),
                   std::to_string(port).c_str(), (char*)nullptr);
            std::_Exit(127);
        }
        pid = p;
        for (int i = 0; i < 60; ++i) {
            std::this_thread::sleep_for(std::chrono::milliseconds(50));
            fn_http::Request r;
            r.url        = std::string("http://") + kHost + ":" + std::to_string(port) + "/ping";
            r.timeout_ms = 500;
            auto res = fn_http::request(r);
            if (res.status == 200) return true;
        }
        return false;
#endif
    }

    void stop() {
#ifndef _WIN32
        if (pid > 0) {
            kill(pid, SIGTERM);
            int st = 0; waitpid(pid, &st, 0);
            pid = 0;
        }
#endif
    }

    std::string base() const {
        return std::string("http://") + kHost + ":" + std::to_string(port);
    }
};

PythonServer& server() {
    static PythonServer s;
    static bool inited = false;
    if (!inited) {
        inited = true;
        s.start();
        std::atexit([] { server().stop(); });
    }
    return s;
}

bool server_alive() { return server().pid > 0; }

} // anon

TEST_CASE("get_json: parses 200 JSON body", "[http_get_json]") {
    if (!server_alive()) { SUCCEED("python3 fixture not available — skipped"); return; }
    auto j = fn_http::get_json(server().base() + "/echo");
    REQUIRE(j.is_object());
    REQUIRE(j.at("ok").get<bool>() == true);
    REQUIRE(j.at("path").get<std::string>() == "/echo");
}

TEST_CASE("get_json: throws on 404", "[http_get_json]") {
    if (!server_alive()) { SUCCEED("python3 fixture not available — skipped"); return; }
    REQUIRE_THROWS_AS(
        fn_http::get_json(server().base() + "/status/404"),
        std::runtime_error);
}

TEST_CASE("get_json: bearer_token reaches server", "[http_get_json]") {
    if (!server_alive()) { SUCCEED("python3 fixture not available — skipped"); return; }
    auto j = fn_http::get_json(server().base() + "/whoami", "tok_42");
    REQUIRE(j.at("auth").get<std::string>() == "Bearer tok_42");
}

TEST_CASE("get_json: throws on invalid JSON", "[http_get_json]") {
    if (!server_alive()) { SUCCEED("python3 fixture not available — skipped"); return; }
    REQUIRE_THROWS_AS(
        fn_http::get_json(server().base() + "/notjson"),
        std::runtime_error);
}