further refactor and simplification

lbry/lbry/extras/daemon/exchange_rate_manager.py

@@ -1,10 +1,9 @@
-import asyncio
-import time
-import logging
 import json
+import time
+import asyncio
+import logging
 from decimal import Decimal
-from typing import Optional
-from json.decoder import JSONDecodeError
+from typing import Optional, Iterable, Type
 from aiohttp.client_exceptions import ClientError
 from lbry.error import InvalidExchangeRateResponseError, CurrencyConversionError
 from lbry.utils import aiohttp_request
@@ -12,10 +11,6 @@ from lbry.wallet.dewies import lbc_to_dewies
 
 log = logging.getLogger(__name__)
 
-CURRENCY_PAIRS = ["USDBTC", "BTCLBC"]
-BITTREX_FEE = 0.0025
-COINBASE_FEE = 0.0  # add fee
-
 
 class ExchangeRate:
     def __init__(self, market, spot, ts):
@@ -28,217 +23,157 @@ class ExchangeRate:
         self.ts = ts
 
     def __repr__(self):
-        out = f"Currency pair:{self.currency_pair}, spot:{self.spot}, ts:{self.ts}"
-        return out
+        return f"Currency pair:{self.currency_pair}, spot:{self.spot}, ts:{self.ts}"
 
     def as_dict(self):
         return {'spot': self.spot, 'ts': self.ts}
 
 
-class Deserializer:
-    def __init__(self, content_type):
-        self.content_type = content_type
-        self._deserializer = self._get_deserializer(content_type)
-
-    def deserialize(self, body):
-        return self._deserializer(body)
-
-    def _get_deserializer(self, content_type):
-        if content_type == 'json':
-            return self._deserialize_json
-        else:
-            raise ValueError('Content type {content_type} is not supported')
-
-    def _deserialize_json(self, body):
-        try:
-            return json.loads(body)
-        except (ValueError, JSONDecodeError):
-            log.error('Failed to deserialize response body: %s', body)
-            raise
-
-
-class AioHttpManager:
-    REQUESTS_TIMEOUT = 20
-
-    def __init__(self, url, params, content_type):
-        self.url = url
-        self.params = params
-        self.content_type = content_type
-
-    async def _make_request(self):
-        async with aiohttp_request('get', self.url, params=self.params) as response:
-            return await response
-
-    async def get_response_body(self):
-        response = await asyncio.wait_for(self._make_request(), self.REQUESTS_TIMEOUT)
-        if self.content_type not in response.headers.get('Content-Type'):
-            raise InvalidExchangeRateResponseError(self.url, f'Received response is not of type {self.content_type}')
-        return response.read().decode()
-
-
 class MarketFeed:
-    EXCHANGE_RATE_UPDATE_RATE_SEC = 300
+    name: str
+    market: str
+    url: str
+    params = {}
+    fee = 0
 
-    def __init__(self, market: str, name: str, url: str, params: dict, fee: float,
-                 content_type: str = 'json', network_manager=AioHttpManager,
-                 deserializer=Deserializer):
-        self.market = market
-        self.name = name
-        self.fee = fee
-        self.rate = None
-        self._network_manager = network_manager(url, params, content_type)
-        self._deserializer = deserializer(content_type)
+    update_interval = 300
+    request_timeout = 50
+
+    def __init__(self):
+        self.rate: Optional[float] = None
+        self.last_check = 0
+        self._last_response = None
         self._task: Optional[asyncio.Task] = None
-        self._online = True
+        self.event = asyncio.Event()
 
-    def rate_is_initialized(self):
+    @property
+    def has_rate(self):
         return self.rate is not None
 
+    @property
     def is_online(self):
-        return self._online
+        return self.last_check+self.update_interval+self.request_timeout > time.time()
 
-    def _on_error(self, err):
-        log.warning("There was a problem updating %s exchange rate information from %s",
-                    self.market, self.name)
-        log.debug("Exchange rate error (%s from %s): %s", self.market, self.name, err)
-        self._online = False
-
-    def _handle_response(self, body):
+    def get_rate_from_response(self, response):
         raise NotImplementedError()
 
-    def _subtract_fee(self, from_amount):
-        # increase amount to account for market fees
-        return from_amount / (1.0 - self.fee)
+    async def get_response(self):
+        async with aiohttp_request('get', self.url, params=self.params, timeout=self.request_timeout) as response:
+            self._last_response = await response.json()
+            return self._last_response
 
-    def _save_price(self, price):
-        log.debug("Saving price update %f for %s from %s" % (price, self.market, self.name))
-        self.rate = ExchangeRate(self.market, price, int(time.time()))
-        self._online = True
-
-    async def _get_current_price(self):
-        body = self._deserializer.deserialize(await self._network_manager.get_response_body())
-        return self._subtract_fee(self._handle_response(body))
-
-    async def _update_price(self):
+    async def get_rate(self):
         try:
-            self._save_price(await self._get_current_price())
-        except (asyncio.TimeoutError, InvalidExchangeRateResponseError, ClientError) as err:
-            self._on_error(err)
+            data = await self.get_response()
+            rate = self.get_rate_from_response(data)
+            rate = rate / (1.0 - self.fee)
+            log.debug("Saving rate update %f for %s from %s", rate, self.market, self.name)
+            self.rate = ExchangeRate(self.market, rate, int(time.time()))
+            self.last_check = time.time()
+            self.event.set()
+            return self.rate
+        except asyncio.CancelledError:
+            raise
+        except asyncio.TimeoutError:
+            log.warning("Timed out fetching exchange rate from %s.", self.name)
+        except json.JSONDecodeError as e:
+            log.warning("Could not parse exchange rate response from %s: %s", self.name, e.doc)
+        except InvalidExchangeRateResponseError as e:
+            log.warning(str(e))
+        except Exception as e:
+            log.exception("Exchange rate error (%s from %s):", self.market, self.name)
 
-    async def _keep_updated(self):
+    async def keep_updated(self):
         while True:
-            self._update_price()
-            await asyncio.sleep(self.EXCHANGE_RATE_UPDATE_RATE_SEC)
+            await self.get_rate()
+            await asyncio.sleep(self.update_interval)
 
     def start(self):
         if not self._task:
-            self._task = asyncio.create_task(self._keep_updated)
+            self._task = asyncio.create_task(self.keep_updated())
 
     def stop(self):
         if self._task and not self._task.done():
             self._task.cancel()
         self._task = None
+        self.event.clear()
 
 
 class BittrexFeed(MarketFeed):
-    def __init__(self):
-        super().__init__(
-            "BTCLBC",
-            "Bittrex",
-            "https://bittrex.com/api/v1.1/public/getmarkethistory",
-            {'market': 'BTC-LBC', 'count': 50},
-            BITTREX_FEE
-        )
+    name = "Bittrex"
+    market = "BTCLBC"
+    url = "https://bittrex.com/api/v1.1/public/getmarkethistory"
+    params = {'market': 'BTC-LBC', 'count': 50}
+    fee = 0.0025
 
-    def _handle_response(self, json_response):
+    def get_rate_from_response(self, json_response):
         if 'result' not in json_response:
             raise InvalidExchangeRateResponseError(self.name, 'result not found')
         trades = json_response['result']
         if len(trades) == 0:
-            raise InvalidExchangeRateResponseError(self.market, 'trades not found')
+            raise InvalidExchangeRateResponseError(self.name, 'trades not found')
         totals = sum([i['Total'] for i in trades])
         qtys = sum([i['Quantity'] for i in trades])
         if totals <= 0 or qtys <= 0:
-            raise InvalidExchangeRateResponseError(self.market, 'quantities were not positive')
+            raise InvalidExchangeRateResponseError(self.name, 'quantities were not positive')
         vwap = totals / qtys
         return float(1.0 / vwap)
 
 
-class LBRYioFeed(MarketFeed):
-    def __init__(self):
-        super().__init__(
-            "BTCLBC",
-            "lbry.com",
-            "https://api.lbry.com/lbc/exchange_rate",
-            {},
-            0.0,
-        )
+class LBRYFeed(MarketFeed):
+    name = "lbry.com"
+    market = "BTCLBC"
+    url = "https://api.lbry.com/lbc/exchange_rate"
 
-    def _handle_response(self, json_response):
+    def get_rate_from_response(self, json_response):
         if 'data' not in json_response:
             raise InvalidExchangeRateResponseError(self.name, 'result not found')
         return 1.0 / json_response['data']['lbc_btc']
 
 
-class LBRYioBTCFeed(MarketFeed):
-    def __init__(self):
-        super().__init__(
-            "USDBTC",
-            "lbry.com",
-            "https://api.lbry.com/lbc/exchange_rate",
-            {},
-            0.0,
-        )
+class LBRYBTCFeed(LBRYFeed):
+    market = "USDBTC"
 
-    def _handle_response(self, json_response):
+    def get_rate_from_response(self, json_response):
         if 'data' not in json_response:
             raise InvalidExchangeRateResponseError(self.name, 'result not found')
         return 1.0 / json_response['data']['btc_usd']
 
 
-class CryptonatorBTCFeed(MarketFeed):
-    def __init__(self):
-        super().__init__(
-            "USDBTC",
-            "cryptonator.com",
-            "https://api.cryptonator.com/api/ticker/usd-btc",
-            {},
-            0.0,
-        )
-
-    def _handle_response(self, json_response):
-        if 'ticker' not in json_response or len(json_response['ticker']) == 0 or \
-                'success' not in json_response or json_response['success'] is not True:
-            raise InvalidExchangeRateResponseError(self.name, 'result not found')
-        return float(json_response['ticker']['price'])
-
-
 class CryptonatorFeed(MarketFeed):
-    def __init__(self):
-        super().__init__(
-            "BTCLBC",
-            "cryptonator.com",
-            "https://api.cryptonator.com/api/ticker/btc-lbc",
-            {},
-            0.0,
-        )
+    name = "cryptonator.com"
+    market = "BTCLBC"
+    url = "https://api.cryptonator.com/api/ticker/btc-lbc"
 
-    def _handle_response(self, json_response):
+    def get_rate_from_response(self, json_response):
         if 'ticker' not in json_response or len(json_response['ticker']) == 0 or \
                 'success' not in json_response or json_response['success'] is not True:
             raise InvalidExchangeRateResponseError(self.name, 'result not found')
         return float(json_response['ticker']['price'])
 
 
+class CryptonatorBTCFeed(CryptonatorFeed):
+    market = "USDBTC"
+    url = "https://api.cryptonator.com/api/ticker/usd-btc"
+
+
+FEEDS: Iterable[Type[MarketFeed]] = (
+    LBRYFeed,
+    LBRYBTCFeed,
+    BittrexFeed,
+    CryptonatorFeed,
+    CryptonatorBTCFeed,
+)
+
+
 class ExchangeRateManager:
-    def __init__(self):
-        self.market_feeds = [
-            LBRYioBTCFeed(),
-            LBRYioFeed(),
-            BittrexFeed(),
-            # CryptonatorBTCFeed(),
-            # CryptonatorFeed()
-        ]
+    def __init__(self, feeds=FEEDS):
+        self.market_feeds = [Feed() for Feed in feeds]
+
+    def wait(self):
+        return asyncio.wait(
+            [feed.event.wait() for feed in self.market_feeds],
+        )
 
     def start(self):
         log.info("Starting exchange rate manager")
@@ -257,11 +192,11 @@ class ExchangeRateManager:
             return round(amount, 8)
 
         for market in self.market_feeds:
-            if (market.rate_is_initialized() and market.is_online() and
+            if (market.has_rate and market.is_online and
                     market.rate.currency_pair == (from_currency, to_currency)):
                 return round(amount * Decimal(market.rate.spot), 8)
         for market in self.market_feeds:
-            if (market.rate_is_initialized() and market.is_online() and
+            if (market.has_rate and market.is_online and
                     market.rate.currency_pair[0] == from_currency):
                 return round(self.convert_currency(
                     market.rate.currency_pair[1], to_currency, amount * Decimal(market.rate.spot)), 8)

lbry/tests/integration/test_exchange_rate_manager.py

@@ -0,0 +1,23 @@
+from decimal import Decimal
+from torba.testcase import AsyncioTestCase
+from lbry.extras.daemon.exchange_rate_manager import (
+    ExchangeRate, ExchangeRateManager
+)
+
+
+class TestExchangeRateManager(AsyncioTestCase):
+
+    async def test_exchange_rate_manager(self):
+        manager = ExchangeRateManager()
+        manager.start()
+        self.addCleanup(manager.stop)
+        for feed in manager.market_feeds:
+            self.assertFalse(feed.is_online)
+            self.assertIsNone(feed.rate)
+        await manager.wait()
+        for feed in manager.market_feeds:
+            self.assertTrue(feed.is_online)
+            self.assertIsInstance(feed.rate, ExchangeRate)
+        lbc = manager.convert_currency('USD', 'LBC', Decimal('0.01'))
+        self.assertGreaterEqual(lbc, 0.1)
+        self.assertLessEqual(lbc, 10.0)

lbry/tests/unit/lbrynet_daemon/test_exchange_rate_manager.py

@@ -1,206 +1,137 @@
-import unittest
-import logging
+import asyncio
 from decimal import Decimal
+from time import time
 from lbry.schema.claim import Claim
-from lbry.extras.daemon import exchange_rate_manager
+from lbry.extras.daemon.exchange_rate_manager import (
+    ExchangeRate, ExchangeRateManager, CurrencyConversionError,
+    LBRYFeed, LBRYBTCFeed,
+    CryptonatorFeed, CryptonatorBTCFeed,
+    BittrexFeed,
+)
 from torba.testcase import AsyncioTestCase
 from lbry.error import InvalidExchangeRateResponseError
-from tests import test_utils
 
 
-class BTCLBCFeed(exchange_rate_manager.MarketFeed):
-    def __init__(self):
-        super().__init__(
-            "BTCLBC",
-            "market name",
-            "derp.com",
-            None,
-            0.0
-        )
-
-
-class USDBTCFeed(exchange_rate_manager.MarketFeed):
-    def __init__(self):
-        super().__init__(
-            "USDBTC",
-            "market name",
-            "derp.com",
-            None,
-            0.0
-        )
-
-
-class DummyExchangeRateManager(exchange_rate_manager.ExchangeRateManager):
+class DummyExchangeRateManager(ExchangeRateManager):
     def __init__(self, market_feeds, rates):
         self.market_feeds = market_feeds
         for feed in self.market_feeds:
-            feed.rate = exchange_rate_manager.ExchangeRate(
-                feed.market, rates[feed.market]['spot'], rates[feed.market]['ts'])
+            feed.last_check = time()
+            feed.rate = ExchangeRate(feed.market, rates[feed.market], time())
 
 
-def get_dummy_exchange_rate_manager(time):
-    rates = {
-        'BTCLBC': {'spot': 3.0, 'ts': time.time() + 1},
-        'USDBTC': {'spot': 2.0, 'ts': time.time() + 2}
-    }
-    return DummyExchangeRateManager([BTCLBCFeed(), USDBTCFeed()], rates)
+def get_dummy_exchange_rate_manager():
+    return DummyExchangeRateManager(
+        [LBRYFeed(), LBRYBTCFeed()],
+        {'BTCLBC': 3.0, 'USDBTC': 2.0}
+    )
 
 
-class ExchangeRateTest(unittest.TestCase):
-    def setUp(self):
-        test_utils.reset_time(self)
+class ExchangeRateTests(AsyncioTestCase):
 
     def test_invalid_rates(self):
         with self.assertRaises(ValueError):
-            exchange_rate_manager.ExchangeRate('USDBTC', 0, test_utils.DEFAULT_ISO_TIME)
+            ExchangeRate('USDBTC', 0, time())
         with self.assertRaises(ValueError):
-            exchange_rate_manager.ExchangeRate('USDBTC', -1, test_utils.DEFAULT_ISO_TIME)
-
-
-class FeeTest(unittest.TestCase):
-    def setUp(self):
-        test_utils.reset_time(self)
+            ExchangeRate('USDBTC', -1, time())
 
     def test_fee_converts_to_lbc(self):
         fee = Claim().stream.fee
         fee.usd = Decimal(10.0)
         fee.address = "bRcHraa8bYJZL7vkh5sNmGwPDERFUjGPP9"
-
-        rates = {
-            'BTCLBC': {'spot': 3.0, 'ts': test_utils.DEFAULT_ISO_TIME + 1},
-            'USDBTC': {'spot': 2.0, 'ts': test_utils.DEFAULT_ISO_TIME + 2}
-        }
-
-        market_feeds = [BTCLBCFeed(), USDBTCFeed()]
-        manager = DummyExchangeRateManager(market_feeds, rates)
+        manager = get_dummy_exchange_rate_manager()
         result = manager.convert_currency(fee.currency, "LBC", fee.amount)
         self.assertEqual(60.0, result)
 
     def test_missing_feed(self):
-        # test when a feed is missing for conversion
         fee = Claim().stream.fee
         fee.usd = Decimal(1.0)
         fee.address = "bRcHraa8bYJZL7vkh5sNmGwPDERFUjGPP9"
-
-        rates = {
-            'BTCLBC': {'spot': 1.0, 'ts': test_utils.DEFAULT_ISO_TIME + 1},
-        }
-        market_feeds = [BTCLBCFeed()]
-        manager = DummyExchangeRateManager(market_feeds, rates)
-        with self.assertRaises(Exception):
+        manager = DummyExchangeRateManager([LBRYFeed()], {'BTCLBC': 1.0})
+        with self.assertRaises(CurrencyConversionError):
             manager.convert_currency(fee.currency, "LBC", fee.amount)
 
-
-class LBRYioFeedTest(unittest.TestCase):
-    def test_handle_response(self):
-        feed = exchange_rate_manager.LBRYioFeed()
-
-        response = {
+    def test_lbry_feed_response(self):
+        feed = LBRYFeed()
+        out = feed.get_rate_from_response({
             'data': {
-                'fresh': 0, 'lbc_usd': 0.05863062523378918, 'lbc_btc': 5.065289549855739e-05, 'btc_usd': 1157.498
+                'fresh': 0, 'lbc_usd': 0.05863062523378918,
+                'lbc_btc': 5.065289549855739e-05, 'btc_usd': 1157.498
             },
             'success': True,
             'error': None
-        }
-        out = feed._handle_response(response)
-        expected = 1.0 / 5.065289549855739e-05
-        self.assertEqual(expected, out)
-
-        response = {}
+        })
+        self.assertEqual(1.0 / 5.065289549855739e-05, out)
         with self.assertRaises(InvalidExchangeRateResponseError):
-            feed._handle_response(response)
-
-        response = {
-            "success": True,
-            "result": []
-        }
+            feed.get_rate_from_response({})
         with self.assertRaises(InvalidExchangeRateResponseError):
-            feed._handle_response(response)
+            feed.get_rate_from_response({
+                "success": True,
+                "result": []
+            })
 
-
-class TestExchangeRateFeeds(unittest.TestCase):
-    def test_handle_lbryio_btc_response(self):
-        feed = exchange_rate_manager.LBRYioBTCFeed()
-
-        response = {
+    def test_lbry_btc_feed_response(self):
+        feed = LBRYBTCFeed()
+        out = feed.get_rate_from_response({
             'data': {
-                'fresh': 0, 'lbc_usd': 0.05863062523378918, 'lbc_btc': 5.065289549855739e-05, 'btc_usd': 1157.498
+                'fresh': 0, 'lbc_usd': 0.05863062523378918,
+                'lbc_btc': 5.065289549855739e-05, 'btc_usd': 1157.498
             },
             'success': True,
             'error': None
-        }
-        out = feed._handle_response(response)
-        expected = 1.0 / 1157.498
-        self.assertEqual(expected, out)
-
-        response = {}
+        })
+        self.assertEqual(1.0 / 1157.498, out)
         with self.assertRaises(InvalidExchangeRateResponseError):
-            out = feed._handle_response(response)
-
-        response = {
-            "success": True,
-            "result": {}
-        }
+            feed.get_rate_from_response({})
         with self.assertRaises(InvalidExchangeRateResponseError):
-            out = feed._handle_response(response)
+            feed.get_rate_from_response({
+                "success": True,
+                "result": {}
+            })
 
-    def test_handle_cryptonator_lbc_response(self):
-        feed = exchange_rate_manager.CryptonatorFeed()
-
-        response = {
+    def test_cryptonator_lbc_feed_response(self):
+        feed = CryptonatorFeed()
+        out = feed.get_rate_from_response({
             'ticker': {
-                'base': 'BTC', 'target': 'LBC', 'price': 23657.44026496, 'volume': '', 'change': -5.59806916,
+                'base': 'BTC', 'target': 'LBC', 'price': 23657.44026496,
+                'volume': '', 'change': -5.59806916,
             },
             'timestamp': 1507470422,
             'success': True,
             'error': ""
-        }
-        out = feed._handle_response(response)
-        expected = 23657.44026496
-        self.assertEqual(expected, out)
-
-        response = {}
+        })
+        self.assertEqual(23_657.44026496, out)
         with self.assertRaises(InvalidExchangeRateResponseError):
-            feed._handle_response(response)
-
-        response = {
-            "success": True,
-            "ticker": {}
-        }
+            feed.get_rate_from_response({})
         with self.assertRaises(InvalidExchangeRateResponseError):
-            feed._handle_response(response)
+            feed.get_rate_from_response({
+                "success": True,
+                "ticker": {}
+            })
 
-    def test_handle_cryptonator_btc_response(self):
-        feed = exchange_rate_manager.CryptonatorBTCFeed()
-
-        response = {
+    def test_cryptonator_btc_feed_response(self):
+        feed = CryptonatorBTCFeed()
+        out = feed.get_rate_from_response({
             'ticker': {
-                'base': 'BTC', 'target': 'LBC', 'price': 0.00022123, 'volume': '', 'change': -0.00000259,
+                'base': 'BTC', 'target': 'LBC', 'price': 0.00022123,
+                'volume': '', 'change': -0.00000259,
             },
             'timestamp': 1507471141,
             'success': True,
             'error': ''
-        }
-
-        out = feed._handle_response(response)
-        expected = 0.00022123
-        self.assertEqual(expected, out)
-
-        response = '{}'
+        })
+        self.assertEqual(0.00022123, out)
         with self.assertRaises(InvalidExchangeRateResponseError):
-            feed._handle_response(response)
-
-        response = {
-            "success": True,
-            "ticker": {}
-        }
+            feed.get_rate_from_response({})
         with self.assertRaises(InvalidExchangeRateResponseError):
-            feed._handle_response(response)
+            feed.get_rate_from_response({
+                "success": True,
+                "ticker": {}
+            })
 
-    def test_handle_bittrex_response(self):
-        feed = exchange_rate_manager.BittrexFeed()
-
-        response = {
+    def test_bittrex_feed_response(self):
+        feed = BittrexFeed()
+        out = feed.get_rate_from_response({
             "success": True,
             "message": "",
             "result": [
@@ -213,102 +144,27 @@ class TestExchangeRateFeeds(unittest.TestCase):
                     "Price": 0.00001592, "Total": 0.00686151, "FillType": "PARTIAL_FILL", "OrderType": "SELL"
                 }
             ]
-        }
-        out = feed._handle_response(response)
-        expected = 1.0 / ((0.00090980+0.00686151) / (56.12611239+430.99988180))
-        self.assertEqual(expected, out)
-
-        response = {}
+        })
+        self.assertEqual(1.0 / ((0.00090980+0.00686151) / (56.12611239+430.99988180)), out)
         with self.assertRaises(InvalidExchangeRateResponseError):
-            feed._handle_response(response)
-
-        response = {
-            "success": True,
-            "result": []
-        }
+            feed.get_rate_from_response({})
         with self.assertRaises(InvalidExchangeRateResponseError):
-            feed._handle_response(response)
+            feed.get_rate_from_response({
+                "success": True,
+                "result": []
+            })
 
 
-class TestMarketFeed(AsyncioTestCase):
-    def setUp(self):
-        self.feed = exchange_rate_manager.MarketFeed('some market', 'some name', 'some url', {'param': 1}, 0.005)
+class BadMarketFeed(LBRYFeed):
 
-    def test_save_price(self):
-        with self.assertLogs('lbry.extras.daemon.exchange_rate_manager', logging.DEBUG) as cm:
-            self.feed._save_price(1)
-        self.assertIn(self.feed.market, ' '.join(cm.output))
-        self.assertIn(self.feed.name, ' '.join(cm.output))
-        self.assertTrue(self.feed.is_online())
-        self.assertIsNotNone(self.feed.rate)
-
-        with self.assertRaises(ValueError):
-            self.feed._save_price(0)
-
-        with self.assertRaises(TypeError):
-            self.feed._save_price('not a price')
-
-    async def test_update_price(self):
-        def mock_handle_response(json_obj):
-            return json_obj['data']['lbc_btc']
-
-        async def get_response_body_mock(self):
-            return '{\"data\": {\"fresh\": 0, \"lbc_usd\": 0.05863062523378918, ' \
-                   '\"lbc_btc\": 5.065289549855739e-05, \"btc_usd\": 1157.498}, ' \
-                   '\"success\": true, \"error\": null}'
-
-        self.feed._handle_response = mock_handle_response
-
-        with unittest.mock.patch.object(
-                exchange_rate_manager.AioHttpManager, 'get_response_body', get_response_body_mock
-        ):
-            await self.feed._update_price()
-        self.assertEqual(self.feed.rate.spot, 5.090743266186672e-05)
-        self.assertTrue(self.feed.is_online())
-
-        async def get_response_body_mock(self):
-            return '<h1>not a json</h1>'
-
-        with unittest.mock.patch.object(
-            exchange_rate_manager.AioHttpManager, 'get_response_body', get_response_body_mock
-        ), self.assertRaises(ValueError):
-            await self.feed._update_price()
+    def get_response(self):
+        raise InvalidExchangeRateResponseError(self.name, 'bad stuff')
 
 
-class TestDeserializer(unittest.TestCase):
-    def test_valid_json(self):
-        deserializer = exchange_rate_manager.Deserializer('json')
-        body = '{"data": "valid json", "some_float": 3.1415, "and_a_dict": {"value": true}}'
-        json_obj = deserializer.deserialize(body)
-        self.assertEqual(json_obj['data'], 'valid json')
-        self.assertEqual(json_obj['some_float'], 3.1415)
-        self.assertTrue(json_obj['and_a_dict']['value'])
+class ExchangeRateManagerTests(AsyncioTestCase):
 
-    def test_invalid_json(self):
-        def assert_raises_error(body):
-            with self.assertRaises(ValueError):
-                deserializer.deserialize(body)
-
-        deserializer = exchange_rate_manager.Deserializer('json')
-        assert_raises_error('<h1>not a json</h1>')
-        assert_raises_error('')
-        assert_raises_error('{')
-
-    def test_invalid_content_type(self):
-        with self.assertRaises(ValueError):
-            exchange_rate_manager.Deserializer('not a format')
-
-
-class TestAioHttpManager(AsyncioTestCase):
-    async def test_get_response_body(self):
-        async def make_request_mock(self):
-            response = unittest.mock.Mock(
-                headers={'Content-Type': 'jibberish'}
-            )
-            return response
-
-        manager = exchange_rate_manager.AioHttpManager('some url', 'some params', 'json')
-        with unittest.mock.patch.object(
-                exchange_rate_manager.AioHttpManager, '_make_request', make_request_mock
-        ), self.assertRaises(InvalidExchangeRateResponseError):
-            await manager.get_response_body()
+    async def test_get_rate_failure_retrieved(self):
+        manager = ExchangeRateManager([BadMarketFeed])
+        manager.start()
+        await asyncio.sleep(1)
+        self.addCleanup(manager.stop)

lbry/tests/unit/stream/test_stream_manager.py

@@ -140,7 +140,7 @@ class TestStreamManager(BlobExchangeTestBase):
                                             AnalyticsManager(self.client_config,
                                                              binascii.hexlify(generate_id()).decode(),
                                                              binascii.hexlify(generate_id()).decode()))
-        self.exchange_rate_manager = get_dummy_exchange_rate_manager(time)
+        self.exchange_rate_manager = get_dummy_exchange_rate_manager()
 
     async def _test_time_to_first_bytes(self, check_post, error=None, after_setup=None):
         await self.setup_stream_manager()