packages/kosong/test/simple-toolset.test.ts

import type { ToolCall } from '#/message';
import type { JsonValue } from './fixtures/args-validator';
import { SimpleToolset, toolOk } from './fixtures/simple-toolset';
import type { ToolReturnValue } from './fixtures/simple-toolset';
import { describe, expect, it } from 'vitest';
function makeToolCall(id: string, name: string, args: string | null): ToolCall {
  return {
    type: 'function',
    id,
    name, arguments: args,
  };
}
describe('SimpleToolset', () => {
  it('handle() invokes the registered handler and returns ToolResult', async () => {
    const toolset = new SimpleToolset();
    toolset.add(
      { name: 'plus', description: 'Add two numbers', parameters: {} },
      async (args: JsonValue): Promise<ToolReturnValue> => {
        const obj = args as Record<string, JsonValue>;
        const a = obj['a'] as number;
        const b = obj['b'] as number;
        return toolOk({ output: String(a + b) });
      },
    );

    const tc = makeToolCall('1', 'plus', '{"a": 1, "b": 2}');
    const result = await toolset.handle(tc);

    expect(result.toolCallId).toBe('1');
    expect(result.returnValue.isError).toBe(false);
    expect(result.returnValue.output).toBe('3');
  });

  it('handle() returns toolNotFoundError for unknown tool', async () => {
    const toolset = new SimpleToolset();

    const tc = makeToolCall('1', 'not_found', null);
    const result = await toolset.handle(tc);

    expect(result.toolCallId).toBe('1');
    expect(result.returnValue.isError).toBe(true);
    expect(result.returnValue.message).toContain('not_found');
  });

  it('handle() returns toolParseError on invalid JSON', async () => {
    const toolset = new SimpleToolset();
    toolset.add(
      { name: 'test', description: 'test', parameters: {} },
      async (): Promise<ToolReturnValue> => toolOk({ output: 'ok' }),
    );

    const tc = makeToolCall('1', 'test', '{invalid json}');
    const result = await toolset.handle(tc);

    expect(result.toolCallId).toBe('1');
    expect(result.returnValue.isError).toBe(true);
    expect(result.returnValue.message).toContain('Error parsing JSON arguments:');
    expect(result.returnValue.display).toEqual(
      expect.arrayContaining([
        expect.objectContaining({ type: 'brief', text: 'Invalid arguments' }),
      ]),
    );
  });

  it('handle() returns toolRuntimeError when handler throws', async () => {
    const toolset = new SimpleToolset();
    toolset.add(
      { name: 'explode', description: 'Throws', parameters: {} },
      async (): Promise<ToolReturnValue> => {
        throw new Error('boom');
      },
    );

    const tc = makeToolCall('1', 'explode', '{}');
    const result = await toolset.handle(tc);

    expect(result.toolCallId).toBe('1');
    expect(result.returnValue.isError).toBe(true);
    expect(result.returnValue.message).toBe('Error running tool: boom');
    expect(result.returnValue.display).toEqual(
      expect.arrayContaining([
        expect.objectContaining({ type: 'brief', text: 'Tool runtime error' }),
      ]),
    );
  });

  it('handle() resolves to toolRuntimeError when the handler throws synchronously', async () => {
    const toolset = new SimpleToolset();
    toolset.add(
      { name: 'explode_sync', description: 'Throws synchronously', parameters: {} },
      (): Promise<ToolReturnValue> => {
        throw new Error('boom');
      },
    );

    await expect(toolset.handle(makeToolCall('1', 'explode_sync', '{}'))).resolves.toMatchObject({
      toolCallId: '1',
      returnValue: expect.objectContaining({
        isError: true,
        message: expect.stringContaining('boom'),
      }),
    });
  });

  it('handle() resolves to toolRuntimeError when the handler returns Promise.reject()', async () => {
    const toolset = new SimpleToolset();
    toolset.add(
      { name: 'explode_reject', description: 'Rejects', parameters: {} },
      async (): Promise<ToolReturnValue> => {
        throw new Error('boom reject');
      },
    );

    await expect(toolset.handle(makeToolCall('1', 'explode_reject', '{}'))).resolves.toMatchObject({
      toolCallId: '1',
      returnValue: expect.objectContaining({
        isError: true,
        message: expect.stringContaining('boom reject'),
      }),
    });
  });

  it('handle() returns toolValidateError when arguments do not satisfy parameters schema', async () => {
    const toolset = new SimpleToolset();
    let handlerCalled = false;
    toolset.add(
      {
        name: 'needs_x',
        description: 'Requires x',
        parameters: {
          type: 'object',
          properties: {
            x: { type: 'string' },
          },
          required: ['x'],
        },
      },
      async (): Promise<ToolReturnValue> => {
        handlerCalled = true;
        return toolOk({ output: 'ok' });
      },
    );

    const result = await toolset.handle(makeToolCall('1', 'needs_x', '{}'));

    expect(result.toolCallId).toBe('1');
    expect(result.returnValue.isError).toBe(true);
    expect(result.returnValue.message).toContain('Error validating JSON arguments:');
    expect(result.returnValue.message).toContain('x');
    expect(result.returnValue.display).toEqual(
      expect.arrayContaining([
        expect.objectContaining({ type: 'brief', text: 'Invalid arguments' }),
      ]),
    );
    expect(handlerCalled).toBe(false);
  });

  it('add() and remove() manage tools', () => {
    const toolset = new SimpleToolset();

    expect(toolset.tools).toHaveLength(0);

    toolset.add(
      { name: 'a', description: 'tool a', parameters: {} },
      async (): Promise<ToolReturnValue> => toolOk({ output: '' }),
    );
    toolset.add(
      { name: 'b', description: 'tool b', parameters: {} },
      async (): Promise<ToolReturnValue> => toolOk({ output: '' }),
    );

    expect(toolset.tools).toHaveLength(2);
    expect(toolset.tools.map((t) => t.name)).toEqual(['a', 'b']);

    toolset.remove('a');
    expect(toolset.tools).toHaveLength(1);
    expect(toolset.tools[0]!.name).toBe('b');
  });

  it('add() overwrites existing tool with same name', async () => {
    const toolset = new SimpleToolset();

    toolset.add(
      { name: 'tool', description: 'v1', parameters: {} },
      async (): Promise<ToolReturnValue> => toolOk({ output: 'v1' }),
    );
    toolset.add(
      { name: 'tool', description: 'v2', parameters: {} },
      async (): Promise<ToolReturnValue> => toolOk({ output: 'v2' }),
    );

    expect(toolset.tools).toHaveLength(1);
    expect(toolset.tools[0]!.description).toBe('v2');

    const tc = makeToolCall('1', 'tool', '{}');
    const result = await toolset.handle(tc);
    expect(result.returnValue.output).toBe('v2');
  });

  it('handle() uses empty object when arguments is null', async () => {
    const toolset = new SimpleToolset();
    let receivedArgs: JsonValue = null;
    toolset.add(
      { name: 'tool', description: 'test', parameters: {} },
      async (args: JsonValue): Promise<ToolReturnValue> => {
        receivedArgs = args;
        return toolOk({ output: 'ok' });
      },
    );

    const tc = makeToolCall('1', 'tool', null);
    await toolset.handle(tc);

    expect(receivedArgs).toEqual({});
  });

  it('remove() throws for non-existent tool', () => {
    const toolset = new SimpleToolset();
    expect(() => {
      toolset.remove('does-not-exist');
    }).toThrow('Tool `does-not-exist` not found in the toolset.');
  });

  it('validation error message uses "must NOT have additional property" for additionalProperties: false', async () => {
    const toolset = new SimpleToolset();
    toolset.add(
      {
        name: 'strict_tool',
        description: 'rejects unknown keys',
        parameters: {
          type: 'object',
          properties: {
            x: { type: 'string' },
          },
          required: ['x'],
          additionalProperties: false,
        },
      },
      async (): Promise<ToolReturnValue> => toolOk({ output: 'ok' }),
    );

    const result = await toolset.handle(makeToolCall('1', 'strict_tool', '{"x":"a","extra":1}'));
    expect(result.returnValue.isError).toBe(true);
    expect(result.returnValue.message).toContain("must NOT have additional property 'extra'");
  });

  it('validation error message includes instancePath for nested field errors', async () => {
    const toolset = new SimpleToolset();
    toolset.add(
      {
        name: 'nested_tool',
        description: 'expects nested object',
        parameters: {
          type: 'object',
          properties: {
            user: {
              type: 'object',
              properties: {
                age: { type: 'integer' },
              },
              required: ['age'],
            },
          },
          required: ['user'],
        },
      },
      async (): Promise<ToolReturnValue> => toolOk({ output: 'ok' }),
    );

    // Pass age as string, triggering a type error on the nested path.
    const result = await toolset.handle(
      makeToolCall('1', 'nested_tool', '{"user":{"age":"not a number"}}'),
    );
    expect(result.returnValue.isError).toBe(true);
    // Error message should mention the instance path `/user/age`.
    expect(result.returnValue.message).toContain('/user/age');
  });
});