bots: Extract request_test_lib.py.

The new module mocks out calls to the requests library, which
is used by many of our bots that use third party services.

Mocking of requests.py is mostly orthogonal to our other
testing concerns.

zulip_bots/zulip_bots/request_test_lib.py

@@ -0,0 +1,81 @@
+import json
+import requests
+
+from contextlib import contextmanager
+from mock import patch
+
+from typing import Any, Dict, List
+
+@contextmanager
+def mock_http_conversation(http_data):
+    # type: (Dict[str, Any]) -> Any
+    """
+    Use this context manager to mock and verify a bot's HTTP
+    requests to the third-party API (and provide the correct
+    third-party API response. This allows us to test things
+    that would require the Internet without it).
+
+    http_data should be fixtures data formatted like the data
+    in zulip_bots/zulip_bots/bots/giphy/fixtures/test_normal.json
+    """
+    def get_response(http_response, http_headers):
+        # type: (Dict[str, Any], Dict[str, Any]) -> Any
+        """Creates a fake `requests` Response with a desired HTTP response and
+        response headers.
+        """
+        mock_result = requests.Response()
+        mock_result._content = json.dumps(http_response).encode()  # type: ignore # This modifies a "hidden" attribute.
+        mock_result.status_code = http_headers.get('status', 200)
+        return mock_result
+
+    def assert_called_with_fields(mock_result, http_request, fields):
+        # type: (Any, Dict[str, Any], List[str]) -> None
+        """Calls `assert_called_with` on a mock object using an HTTP request.
+        Uses `fields` to determine which keys to look for in HTTP request and
+        to test; if a key is in `fields`, e.g., 'headers', it will be used in
+        the assertion.
+        """
+        args = {}
+
+        for field in fields:
+            if field in http_request:
+                args[field] = http_request[field]
+
+        mock_result.assert_called_with(http_request['api_url'], **args)
+
+    http_request = http_data.get('request')
+    http_response = http_data.get('response')
+    http_headers = http_data.get('response-headers')
+    http_method = http_request.get('method', 'GET')
+
+    if http_method == 'GET':
+        with patch('requests.get') as mock_get:
+            mock_get.return_value = get_response(http_response, http_headers)
+            yield
+            assert_called_with_fields(
+                mock_get,
+                http_request,
+                ['params', 'headers']
+            )
+    else:
+        with patch('requests.post') as mock_post:
+            mock_post.return_value = get_response(http_response, http_headers)
+            yield
+            assert_called_with_fields(
+                mock_post,
+                http_request,
+                ['params', 'headers', 'json']
+            )
+
+@contextmanager
+def mock_request_exception():
+    # type: () -> Any
+    def assert_mock_called(mock_result):
+        # type: (Any) -> None
+        mock_result.assert_called()
+
+    with patch('requests.get') as mock_get:
+        mock_get.return_value = True
+        mock_get.side_effect = requests.exceptions.RequestException
+        yield
+        assert_mock_called(mock_get)

zulip_bots/zulip_bots/test_lib.py

@@ -1,16 +1,19 @@
 import json
 import mock
 import os
-import requests
 
 from mock import patch
 
-from contextlib import contextmanager
 from importlib import import_module
 from unittest import TestCase
 
 from typing import List, Dict, Any, Tuple
 
+from zulip_bots.request_test_lib import (
+    mock_http_conversation,
+    mock_request_exception,
+)
+
 from zulip_bots.simple_lib import (
     SimpleStorage,
     SimpleMessageServer,
@@ -185,77 +188,3 @@ def read_bot_fixture_data(bot_name, test_name):
         content = f.read()
     http_data = json.loads(content)
     return http_data
-
-@contextmanager
-def mock_http_conversation(http_data):
-    # type: (Dict[str, Any]) -> Any
-    """
-    Use this context manager to mock and verify a bot's HTTP
-    requests to the third-party API (and provide the correct
-    third-party API response. This allows us to test things
-    that would require the Internet without it).
-
-    http_data should be fixtures data formatted like the data
-    in zulip_bots/zulip_bots/bots/giphy/fixtures/test_normal.json
-    """
-    def get_response(http_response, http_headers):
-        # type: (Dict[str, Any], Dict[str, Any]) -> Any
-        """Creates a fake `requests` Response with a desired HTTP response and
-        response headers.
-        """
-        mock_result = requests.Response()
-        mock_result._content = json.dumps(http_response).encode()  # type: ignore # This modifies a "hidden" attribute.
-        mock_result.status_code = http_headers.get('status', 200)
-        return mock_result
-
-    def assert_called_with_fields(mock_result, http_request, fields):
-        # type: (Any, Dict[str, Any], List[str]) -> None
-        """Calls `assert_called_with` on a mock object using an HTTP request.
-        Uses `fields` to determine which keys to look for in HTTP request and
-        to test; if a key is in `fields`, e.g., 'headers', it will be used in
-        the assertion.
-        """
-        args = {}
-
-        for field in fields:
-            if field in http_request:
-                args[field] = http_request[field]
-
-        mock_result.assert_called_with(http_request['api_url'], **args)
-
-    http_request = http_data.get('request')
-    http_response = http_data.get('response')
-    http_headers = http_data.get('response-headers')
-    http_method = http_request.get('method', 'GET')
-
-    if http_method == 'GET':
-        with patch('requests.get') as mock_get:
-            mock_get.return_value = get_response(http_response, http_headers)
-            yield
-            assert_called_with_fields(
-                mock_get,
-                http_request,
-                ['params', 'headers']
-            )
-    else:
-        with patch('requests.post') as mock_post:
-            mock_post.return_value = get_response(http_response, http_headers)
-            yield
-            assert_called_with_fields(
-                mock_post,
-                http_request,
-                ['params', 'headers', 'json']
-            )
-
-@contextmanager
-def mock_request_exception():
-    # type: () -> Any
-    def assert_mock_called(mock_result):
-        # type: (Any) -> None
-        mock_result.assert_called()
-
-    with patch('requests.get') as mock_get:
-        mock_get.return_value = True
-        mock_get.side_effect = requests.exceptions.RequestException
-        yield
-        assert_mock_called(mock_get)