rea/tests/support/reverseDebuggerMcpTestHelpers.ts

import { readFile, rm } from "node:fs/promises";

import type { Client } from "@modelcontextprotocol/client";
import { Ajv2020 } from "ajv/dist/2020.js";
import { expect, onTestFinished } from "vitest";
import { z } from "zod";

import { toolContract } from "../../src/contracts/toolContracts.js";
import type { createServer } from "../../src/server/createServer.js";
import {
  createApplicationMcpHarness,
  type ApplicationMcpHarness,
} from "../fixtures/applicationMcpHarness.js";
import { createTestBinarySession } from "../fixtures/binarySession.js";

export const waitForStartedFile = async (path: string): Promise<void> => {
  await expect
    .poll(() => readFile(path, "utf8").catch(() => ""))
    .toBe("started");
};

export const validateDebuggerStatusResponse = async (
  client: Client,
  name: "gdb_session_status" | "rizin_debug_session_status",
  sessionId: string,
): Promise<Record<string, unknown>> => {
  const listed = (await client.listTools()).tools.find(
    (tool) => tool.name === name,
  );
  if (listed?.outputSchema === undefined)
    throw new Error(`Missing advertised ${name} output schema`);
  const response = await client.callTool({
    name,
    arguments: { session_id: sessionId },
  });
  expect(response.isError).not.toBe(true);
  const parsed = toolContract(name).outputSchema.parse(
    response.structuredContent,
  );
  expect(
    new Ajv2020({ strict: false, validateFormats: false }).validate(
      z.record(z.string(), z.unknown()).parse(listed.outputSchema),
      parsed,
    ),
  ).toBe(true);
  return z.record(z.string(), z.unknown()).parse(parsed);
};

export const createProviderEnvironmentMcpHarness = async (options: {
  readonly directory: string;
  readonly clientName: string;
  readonly serverOptions: NonNullable<Parameters<typeof createServer>[1]>;
}) => {
  let closeHarness: ApplicationMcpHarness["close"] | undefined;
  let directoryOwned = true;
  let closing: Promise<void> | undefined;
  const close = (): Promise<void> => {
    if (closing !== undefined) return closing;
    const attempt = (async () => {
      await closeHarness?.();
      if (!directoryOwned) return;
      await rm(options.directory, { recursive: true, force: true });
      directoryOwned = false;
    })();
    closing = attempt;
    void attempt.catch(() => {
      if (closing === attempt) closing = undefined;
    });
    return attempt;
  };
  onTestFinished(close);

  try {
    const harness = await createApplicationMcpHarness({
      session: createTestBinarySession(() => {
        throw new Error("No binary analysis provider should start");
      }),
      serverOptions: options.serverOptions,
      clientIdentity: { name: options.clientName, version: "1" },
      registerCleanup: (close) => {
        closeHarness = close;
      },
    });
    return { client: harness.client, close };
  } catch (cause) {
    try {
      await close();
    } catch (cleanup) {
      throw new AggregateError(
        [cause, cleanup],
        "Provider environment MCP harness setup and cleanup failed",
        { cause },
      );
    }
    throw cause;
  }
};