Debug & Testing

This section will breakdown some of the ways to debug and test the code. You are not entirely required to use the options during your development process.

Option 1. Unit Test Cases

For each tasks(1->3), you are required to create a unit test case. Namely they are test_*_order_book_tracker.py, test_*_user_stream_tracker.py and test_*_market.py. Examples can be found in the test/integration folder.

Below are a list of items required for the Unit Tests:

1. Data Source & Order Tracker | test_*_order_book_tracker.py
   The purpose of this test is to ensure that the OrderBookTrackerDataSource and OrderBookTracker and all its functions are working as intended. Another way to test its functionality is using a Debugger to ensure that the contents OrderBook mirrors that on the exchange.

2. User Stream Tracker | test_*_user_stream_tracker.py
   The purpose of this test is to ensure that the UserStreamTrackerDataSource and UserStreamTracker components are working as intended. This only applies to exchanges that has a WebSocket API. As seen in the examples for this test, it simply outputs all the user stream messages. It is still required that certain actions(buy and cancelling orders) be performed for the tracker to capture. Manual message comparison would be required.

   i.e. Placing a single LIMIT-BUY order on Bittrex Exchange should return the following(some details are omitted)
   
   ```Bash tab="Order Detail(s)"
   Trading Pair: ZRX-ETH
   Order Type: LIMIT-BUY
   Amount: 100ZRX
   Price: 0.00160699ETH
   ```
   
   ```Bash tab="Action(s) Performed"
   1. Placed LIMIT BUY order.
   2. Cancel order.
   ```
   
   ```Bash tab="Expected output"
   # Below is the outcome of the test. Determining if this is accurate would still be necessaru.
   
   <Queue maxsize=0 _queue=[
       BittrexOrderBookMessage(
           type=<OrderBookMessageType.DIFF: 2>,
           content={
               'event_type': 'uB',
               'content': {
                   'N': 4,
                   'd': {
                       'U': '****',
                       'W': 3819907,
                       'c': 'ETH',
                       'b': 1.13183357,
                       'a': 0.96192245,
                       'z': 0.0,
                       'p': '0x****',
                       'r': False,
                       'u': 1572909608900,
                       'h': None
                   }
               },
               'error': None,
               'time': '2019-11-04T23:20:08'
           },
           timestamp=1572909608.0
       ),
       BittrexOrderBookMessage(
           type=<OrderBookMessageType.DIFF: 2>,
           content={
               'event_type': 'uO',
               'content': {
                   'w': '****',
                   'N': 44975,
                   'TY': 0,
                   'o': {
                       'U': '****',
                       'I': 3191361360,
                       'OU': '****',
                       'E': 'XRP-ETH',
                       'OT': 'LIMIT_BUY',
                       'Q': 100.0,
                       'q': 100.0,
                       'X': 0.00160699,
                       'n': 0.0,
                       'P': 0.0,
                       'PU': 0.0,
                       'Y': 1572909608900,
                       'C': None,
                       'i': True,
                       'CI': False,
                       'K': False,
                       'k': False,
                       'J': None,
                       'j': None,
                       'u': 1572909608900,
                       'PassthroughUuid': None
                   }
               },
               'error': None,
               'time': '2019-11-04T23:20:08'
           },
           timestamp=1572909608.0
       ),
       BittrexOrderBookMessage(
           type=<OrderBookMessageType.DIFF: 2>,
           content={
               'event_type': 'uB',
               'content': {
                   'N': 5,
                   'd': {
                       'U': '****',
                       'W': 3819907,
                       'c': 'ETH',
                       'b': 1.13183357,
                       'a': 1.1230232,
                       'z': 0.0,
                       'p': '****',
                       'r': False,
                       'u': 1572909611750,
                       'h': None
                   }
               },
               'error': None,
               'time': '2019-11-04T23:20:11'
           },
           timestamp=1572909611.0
       ),
       BittrexOrderBookMessage(
           type=<OrderBookMessageType.DIFF: 2>,
           content={
               'event_type': 'uO',
               'content': {
                   'w': '****',
                   'N': 44976,
                   'TY': 3,
                   'o': {
                       'U': '****',
                       'I': 3191361360,
                       'OU': '****',
                       'E': 'XRP-ETH',
                       'OT': 'LIMIT_BUY',
                       'Q': 100.0,
                       'q': 100.0,
                       'X': 0.00160699,
                       'n': 0.0,
                       'P': 0.0,
                       'PU': 0.0,
                       'Y': 1572909608900,
                       'C': 1572909611750,
                       'i': False,
                       'CI': True,
                       'K': False,
                       'k': False,
                       'J': None,
                       'j': None,
                       'u': 1572909611750,
                       'PassthroughUuid': None
                   }
               },
               'error': None,
               'time': '2019-11-04T23:20:11'
           },
           timestamp=1572909611.0
       )
   ] tasks=4>
   ```

3. Exchange Class Unit Tests | test_*_exchange.py
   The purpose of this test is to ensure that all components and the order life cycle is working as intended. This test determines if the connector is able to place and manage orders.
   All the tests below are required to pass successfully on both real API calls and mocked API calls modes.
   The mocked API calls mode is to facilitate testing where we can run tests as often as we want without incurring costs in transactions and slippage.
   In the mocked mode, we simulate any API calls where exchange API key and secret are required, i.e. in this mode all the tests should pass without using real exchange API credentials.
   
   To simulate REST API responses, please use test.integration.humming_web_app.HummingWebApp, key steps to follow are as below:

• Create environment variables
  
  MOCK_API_ENABLED - true or false - to indicate whether to run the tests in mocked API calls mode
  NEW_EXCHAGE_API_KEY - string - the exchange API key
  NEW_EXCHAGE_API_SECRET - string - the exchange API secret
  In your test_*_market.py

import conf
.
.
.
API_MOCK_ENABLED = conf.mock_api_enabled is not None and conf.mock_api_enabled.lower() in ['true', 'yes', '1']
API_KEY = "XXX" if API_MOCK_ENABLED else conf.binance_api_key
API_SECRET = "YYY" if API_MOCK_ENABLED else conf.binance_api_secret

• Start HummingWebApp
  Configure the web app on what url host to mock and which url paths to ignore, then start the web app.

@classmethod
def setUpClass(cls):
    cls.ev_loop = asyncio.get_event_loop()
    if API_MOCK_ENABLED:
        cls.web_app = HummingWebApp.get_instance()
        cls.web_app.add_host_to_mock(API_HOST, ["/products", "/currencies"])
        cls.web_app.start()
        cls.ev_loop.run_until_complete(cls.web_app.wait_til_started())

• Patch http requests
  If you use requests library:

cls._req_patcher = mock.patch.object(requests.Session, "request", autospec=True)
cls._req_url_mock = cls._req_patcher.start()
cls._req_url_mock.side_effect = HummingWebApp.reroute_request

If you use aiohttp library:

cls._patcher = mock.patch("aiohttp.client.URL")
cls._url_mock = cls._patcher.start()
cls._url_mock.side_effect = cls.web_app.reroute_local

• Preset json responses
  Use update_response to store the mocked response to the endpoint which you want to mock, e.g.

cls.web_app.update_response("get", cls.base_api_url, "/api/v3/account", FixtureBinance.GET_ACCOUNT)

Please store your mocked json response in test/integration/assets/mock_data/fixture_new_exchange.py e.g.

class FixtureBinance:
GET_ACCOUNT = {"makerCommission": 10, "takerCommission": 10, "buyerCommission": 0, "sellerCommission": 0,
                 "canTrade": True, "canWithdraw": True, "canDeposit": True, "updateTime": 1580009996654,
                 "accountType": "SPOT", "balances": [{"asset": "BTC", "free": "0.00000000", "locked": "0.00000000"},
                                                     {"asset": "ETH", "free": "0.77377698", "locked": "0.00000000"},
                                                     {"asset": "LINK", "free": "4.99700000", "locked": "0.00000000"}]}

Please remove any sensitive information from this file, e.g. your account number, keys, secrets,...

To simulate web socket API responses, please use test.integration.humming_ws_server.HummingWsServerFactory.
Key steps to follow are as below:

• Start new server for each web socket connection
  

@classmethod
def setUpClass(cls):
    cls.ev_loop = asyncio.get_event_loop()
    if API_MOCK_ENABLED:
        ws_base_url = "wss://stream.binance.com:9443/ws"
        cls._ws_user_url = f"{ws_base_url}/{FixtureBinance.GET_LISTEN_KEY['listenKey']}"
        HummingWsServerFactory.start_new_server(cls._ws_user_url)
        HummingWsServerFactory.start_new_server(f"{ws_base_url}/linketh@depth/zrxeth@depth")

• Patch websockets
  

cls._ws_patcher = unittest.mock.patch("websockets.connect", autospec=True)
cls._ws_mock = cls._ws_patcher.start()
cls._ws_mock.side_effect = HummingWsServerFactory.reroute_ws_connect

• Send json responses
  In the code where you are expecting json response from the server.

HummingWsServerFactory.send_json_threadsafe(self._ws_user_url, data1, delay=0.1)
HummingWsServerFactory.send_json_threadsafe(self._ws_user_url, data2, delay=0.11)

data is your fixture data.
Make sure to set some delay if sequence of responses matters, in the above example, data2 is supposed to arrive after data1

In cases where you need to preset client_order_id (our internal id), please mock it as below:

• Patch get_tracking_nonce

  Copy

  cls._t_nonce_patcher = unittest.mock.patch("hummingbot.core.utils.tracking_nonce.get_tracking_nonce")
  cls._t_nonce_mock = cls._t_nonce_patcher.start()

• Mock the nonce and create order_id as required

  Copy

  self._t_nonce_mock.return_value = 10001
  order_id = f"{side.lower()}-{trading_pair}-{str(nonce)}"

Finally, stop all patchers and the web app.
Once all tests are done, stop all these services.

@classmethod
def tearDownClass(cls) -> None:
  if API_MOCK_ENABLED:
      cls.web_app.stop()
      cls._patcher.stop()
      cls._req_patcher.stop()
      cls._ws_patcher.stop()
      cls._t_nonce_patcher.stop()

Option 2. aiopython console

This option is mainly used to test for specific functions. Considering that many of the functions are asynchronous functions, it would be easier to test for these in the aiopython console. Click here for some documentation on how to use aiopython.

Writing short code snippets to examine API responses and/or how certain functions in the code base work would help you understand the expected side-effects of these functions and the overall logic of the Hummingbot client.

Issue a API Request

Below is just a short example on how to write a short asynchronous function to mimic a API request to place an order and displaying the response received.

# Prints the response of a sample LIMIT-BUY Order
# Replace the URL and params accordingly.

>>> import aiohttp
>>> URL="api.test.com/buyOrder"
>>> params = {
...     "symbol": "ZRXETH",
...     "amount": "1000",
...     "price": "0.001",
...     "order_type": "LIMIT"
... }
>>> async with aiohttp.ClientSession() as client:
...    async with client.request("POST",
...                              url=URL,
...                              params=params) as response:
...        if response == 200:
...            print(await response.json())

Calling a Class Method

i.e. Printing the output from get_active_exchange_markets() function in OrderBookTrackerDataSource.

# In this example, we will be using BittrexAPIOrderBookDataSource

>>> from hummingbot.market.bittrex.BittrexAPIOrderBookDataSource import BittrexAPIOrderBookDataSource as b
>>> await b.get_active_exchange_markets()

                 askRate baseAsset        baseVolume  ...             volume     USDVolume old_symbol
symbol                                                ...
BTC-USD    9357.49900000       BTC  2347519.11072768  ...       251.26097386  2.351174e+06    USD-BTC
XRP-BTC       0.00003330       XRP       83.81218622  ...   2563786.10102864  7.976883e+05    BTC-XRP
BTC-USDT   9346.88236735       BTC   538306.04864142  ...        57.59973765  5.379616e+05   USDT-BTC
.
.
.
[339 rows x 18 columns]

Option 3. Custom Scripts

This option, like in Option 2, is mainly used to test specific functions. This is mainly useful when debugging how various functions/classes interact with one another.

i.e. Initializing a simple websocket connection to listen and output all captured messages to examine the user stream message when placing/cancelling an order. This is helpful when determining the exact response fields to use.

i.e. A simple function to craft the Authentication signature of a request. This together with POSTMAN can be used to check if you are generating the appropriate authentication signature for the respective requests.

API Request: POST Order

Below is a sample code for executing a LIMIT-BUY order on Bittrex. This script not only tests the BittrexAuth class but also outputs the response from the API server.

#!/usr/bin/env python3

import asyncio
import aiohttp
from typing import Dict
from hummingbot.connector.exchange.bittrex.bittrex_auth import BittrexAuth

BITTREX_API_ENDPOINT = "https://api.bittrex.com/v3"

async def _api_request(http_method: str,
                       path_url: str = None,
                       params: Dict[str, any] = None,
                       body: Dict[str, any] = None,
                       ):
    url = f"{BITTREX_API_ENDPOINT}{path_url}"

    auth = BittrexAuth(
        "****",
        "****"
    )

    auth_dict = auth.generate_auth_dict(http_method, url, params, body, '')

    headers = auth_dict["headers"]

    if body:
        body = auth_dict["body"]

    client = aiohttp.ClientSession()

    async with client.request(http_method,
                              url=url,
                              headers=headers,
                              params=params,
                              data=body) as response:
        data: Dict[str, any] = await response.json()
        if response.status not in [200,201]:
            print(f"Error occurred. HTTP Status {response.status}: {data}")
        print(data)

# POST order
path_url = "/orders"

body = {
    "marketSymbol": "FXC-BTC",
    "direction": "BUY",
    "type": "LIMIT",
    "quantity": "1800",
    "limit": "3.17E-7",  # Note: This will throw an error
    "timeInForce": "GOOD_TIL_CANCELLED"
}

loop = asyncio.get_event_loop()
loop.run_until_complete(_api_request("POST",path_url=path_url,body=body))
loop.close()

Option 4: Using Debugger tools.

This section will detail the necessary configurations/setup required to run the debugger tool from your IDE of choice.

VS Code

Include the following debug configurations into the launch.json configuration file

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Python: Hummingbot Application",
      "type": "python",
      "request": "launch",
      "program": "${workspaceRoot}/bin/hummingbot.py",
      "console": "integratedTerminal"
    }
  ]
}

Now by executing the Start Debugging command, the debugger will automatically attach itself to the Hummingbot process. The Hummingbot app will appear in the integratedTerminal. You may change this as desired.

PyCharm

Similarly for PyCharm, you want to setup the debug configurations as seen in the screenshot below.