reverse-engineering-anything/tests/boundary/mcp/elfNotesMcp.test.ts

import { readFile, writeFile } from "node:fs/promises";
import { join } from "node:path";
import { expect } from "vitest";
import { toolContract } from "../../../src/contracts/toolContracts.js";
import { createServer } from "../../../src/server/createServer.js";
import { createTestBinarySession } from "../../fixtures/binarySession.js";
import { parseMcpToolError } from "../../fixtures/mcpToolError.js";
import {
  elfExtendedSectionCountFixture,
  compressedElfNoteSectionFixture,
  elfNoteFixture,
  elfNoteWithUnreadableSectionNameFixture,
} from "../../../src/native/elf/ElfNotes.fixture.js";
import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
import { mcpTest, type TestMcp } from "../../support/mcp/mcpFixture.js";

const connect = async (mcp: TestMcp) => {
  const session = createTestBinarySession(() => {
    throw new Error("ELF note inspection must not start a deep provider");
  });
  const client = await mcp.connect(createServer({ kind: "session", session }));
  return { client, session };
};

mcpTest(
  "advertises inspect_elf_notes and reads a GNU build-id",
  async ({ mcp }) => {
    const { client, session } = await connect(mcp);
    try {
      const advertised = (await client.listTools()).tools.find(
        (tool) => tool.name === "inspect_elf_notes",
      );
      expect(advertised?.annotations).toMatchObject({
        readOnlyHint: false,
        idempotentHint: true,
      });
      const root = await createTestTempDirectory("rea-elf-notes-mcp-");
      const path = join(root, "program");
      await writeFile(path, elfNoteFixture({ bits: 32, ownership: "section" }));
      const response = await client.callTool({
        name: "inspect_elf_notes",
        arguments: { path },
      });
      expect(response.isError, JSON.stringify(response.content)).not.toBe(true);
      const evidence = toolContract("inspect_elf_notes").outputSchema.parse(
        response.structuredContent,
      );
      expect(evidence.normalized_result.format).toBe("elf32");
      expect(
        evidence.normalized_result.entries.find(
          (entry) => entry.type_name === "gnu_build_id",
        )?.gnu?.build_id_hex,
      ).toBe("0123456789abcdef0123456789abcdef01234567");
    } finally {
      await session.close();
    }
  },
);

mcpTest("requires an absolute path for inspect_elf_notes", async ({ mcp }) => {
  const { client, session } = await connect(mcp);
  try {
    const response = await client.callTool({
      name: "inspect_elf_notes",
      arguments: { path: "program" },
    });
    expect(response.isError).toBe(true);
    expect(parseMcpToolError(response).error).toMatchObject({
      code: "invalid_request",
      details: { operation: "inspect_elf_notes" },
    });
  } finally {
    await session.close();
  }
});

mcpTest(
  "keeps GNU notes when a section name is not NUL-terminated",
  async ({ mcp }) => {
    const { client, session } = await connect(mcp);
    try {
      const root = await createTestTempDirectory("rea-elf-notes-name-mcp-");
      const path = join(root, "program");
      const bytes = elfNoteWithUnreadableSectionNameFixture("unterminated");
      await writeFile(path, bytes);
      const response = await client.callTool({
        name: "inspect_elf_notes",
        arguments: { path },
      });
      expect(response.isError, JSON.stringify(response.content)).not.toBe(true);
      const evidence = toolContract("inspect_elf_notes").outputSchema.parse(
        response.structuredContent,
      );
      expect(evidence.normalized_result.tables[0]?.name).toBeNull();
      expect(evidence.normalized_result.limitations).toContain(
        "ELF section names are incomplete because a name is not NUL-terminated.",
      );
      expect(evidence.normalized_result.entries[0]?.gnu?.build_id_hex).toBe(
        "0123456789abcdef0123456789abcdef01234567",
      );
      expect(evidence.normalized_result.coverage).toMatchObject({
        status: "complete",
        examined_tables: 1,
        examined_entries: 1,
      });
      expect(Buffer.compare(await readFile(path), bytes)).toBe(0);
    } finally {
      await session.close();
    }
  },
);

mcpTest(
  "reports compressed note storage as unsupported without mutation",
  async ({ mcp }) => {
    const { client, session } = await connect(mcp);
    try {
      const root = await createTestTempDirectory("rea-elf-notes-storage-mcp-");
      const path = join(root, "debug-notes.o");
      const bytes = compressedElfNoteSectionFixture();
      await writeFile(path, bytes);
      const response = await client.callTool({
        name: "inspect_elf_notes",
        arguments: { path },
      });
      expect(response.isError).toBe(true);
      expect(parseMcpToolError(response).error).toMatchObject({
        code: "unsupported_target",
        message: expect.stringContaining(
          "Compressed ELF note sections are unsupported",
        ),
      });
      expect(Buffer.compare(await readFile(path), bytes)).toBe(0);
    } finally {
      await session.close();
    }
  },
);

mcpTest(
  "reports valid extended numbering as unsupported without mutation",
  async ({ mcp }) => {
    const { client, session } = await connect(mcp);
    try {
      const root = await createTestTempDirectory("rea-elf-notes-extended-mcp-");
      const path = join(root, "extended-count.elf");
      await writeFile(path, elfExtendedSectionCountFixture());
      const before = await readFile(path);
      const response = await client.callTool({
        name: "inspect_elf_notes",
        arguments: { path },
      });
      expect(response.isError).toBe(true);
      expect(parseMcpToolError(response).error).toMatchObject({
        code: "unsupported_target",
        message: expect.stringContaining(
          "ELF extended numbering is unsupported",
        ),
      });
      expect((await readFile(path)).equals(before)).toBe(true);
    } finally {
      await session.close();
    }
  },
);

mcpTest(
  "rejects dangling section-name references and recovers in the same session",
  async ({ mcp }) => {
    const { client, session } = await connect(mcp);
    try {
      const root = await createTestTempDirectory("rea-elf-notes-presence-mcp-");
      const path = join(root, "program");
      const bytes = elfNoteFixture({ ownership: "program" });
      bytes.writeUInt16LE(5, 62);
      await writeFile(path, bytes);
      const rejected = await client.callTool({
        name: "inspect_elf_notes",
        arguments: { path },
      });
      expect(rejected.isError).toBe(true);
      expect(parseMcpToolError(rejected).error).toMatchObject({
        code: "invalid_request",
        category: "invalid_input",
        details: {
          issues: [
            expect.objectContaining({
              path: ["path"],
              reason: "invalid_format",
              message: "ELF section table is missing",
            }),
          ],
        },
      });
      expect((await readFile(path)).equals(bytes)).toBe(true);
      bytes.writeUInt16LE(0, 62);
      await writeFile(path, bytes);
      const accepted = await client.callTool({
        name: "inspect_elf_notes",
        arguments: { path },
      });
      expect(accepted.isError).not.toBe(true);
      const evidence = toolContract("inspect_elf_notes").outputSchema.parse(
        accepted.structuredContent,
      );
      expect(evidence.normalized_result.entries[0]?.gnu?.build_id_hex).toBe(
        "0123456789abcdef0123456789abcdef01234567",
      );
    } finally {
      await session.close();
    }
  },
);