metamask-extension/app/scripts/lib/createMetaRPCHandler.test.js

import { obj as createThoughStream } from 'through2';
import createMetaRPCHandler from './createMetaRPCHandler';

describe('createMetaRPCHandler', () => {
  it('can call the api when handler receives a JSON-RPC request', () => {
    const api = {
      foo: (param1) => {
        expect(param1).toStrictEqual('bar');
      },
    };
    const streamTest = createThoughStream();
    const handler = createMetaRPCHandler(api, streamTest);
    handler({
      id: 1,
      method: 'foo',
      params: ['bar'],
    });
  });
  it('can write the response to the outstream', () => {
    const api = {
      foo: (param1) => {
        expect(param1).toStrictEqual('bar');
        return 'foobarbaz';
      },
    };
    const streamTest = createThoughStream();
    const handler = createMetaRPCHandler(api, streamTest);
    handler({
      id: 1,
      method: 'foo',
      params: ['bar'],
    });
    streamTest.on('data', (data) => {
      expect(data.result).toStrictEqual('foobarbaz');
      streamTest.end();
    });
  });
  it('can write an async response to the outstream', () => {
    const api = {
      foo: async (param1) => {
        expect(param1).toStrictEqual('bar');
        await new Promise((resolve) => setTimeout(() => resolve(), 100));
        return 'foobarbaz';
      },
    };
    const streamTest = createThoughStream();
    const handler = createMetaRPCHandler(api, streamTest);
    handler({
      id: 1,
      method: 'foo',
      params: ['bar'],
    });
    streamTest.on('data', (data) => {
      expect(data.result).toStrictEqual('foobarbaz');
      streamTest.end();
    });
  });
  it('can write the error to the outstream when method throws an error', () => {
    const api = {
      foo: (param1) => {
        expect(param1).toStrictEqual('bar');
        throw new Error('foo-error');
      },
    };
    const streamTest = createThoughStream();
    const handler = createMetaRPCHandler(api, streamTest);
    handler({
      id: 1,
      method: 'foo',
      params: ['bar'],
    });
    streamTest.on('data', (data) => {
      expect(data.error.message).toStrictEqual('foo-error');
      streamTest.end();
    });
  });
  it('can not throw an error for writing an error after end', () => {
    const api = {
      foo: (param1) => {
        expect(param1).toStrictEqual('bar');
        throw new Error('foo-error');
      },
    };
    const streamTest = createThoughStream();
    const handler = createMetaRPCHandler(api, streamTest);
    streamTest.end();
    expect(() => {
      handler({
        id: 1,
        method: 'foo',
        params: ['bar'],
      });
    }).not.toThrow();
  });
  it('can not throw an error for write after end', () => {
    const api = {
      foo: (param1) => {
        expect(param1).toStrictEqual('bar');
        return {
          foo: 'bar',
        };
      },
    };
    const streamTest = createThoughStream();
    const handler = createMetaRPCHandler(api, streamTest);
    streamTest.end();
    expect(() => {
      handler({
        id: 1,
        method: 'foo',
        params: ['bar'],
      });
    }).not.toThrow();
  });
});