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toBeSuccessful()

Checks that a tool call result is successful (does not have isError set to true).

This matcher works with ToolCallResult instances returned by app.callTool().

Usage​

const result = await app.callTool('write_file', {
  path: '/tmp/test.txt',
  content: 'Hello'
});
await expect(result).toBeSuccessful();

Parameters​

None

Example​

import { mcpShell } from 'expect-mcp';
import { test, expect } from 'vitest';

test('validate tool call success', async () => {
  const app = mcpShell('node file-server.js');
  await app.initialize();

  const result = await app.callTool('write_file', {
    path: '/tmp/test.txt',
    content: 'Hello world'
  });

  // Check that the tool call succeeded
  await expect(result).toBeSuccessful();

  await app.close();
});

See Also​