bot docs: Simplify docs on writing bot tests.

These changes catch up to some recent improvements in the
test system, plus I eliminate some unnecessary sections.

templates/zerver/api/writing-bots.md

@@ -399,28 +399,30 @@ refactor them.
 
  Let's have a look at a simple test suite for the [`helloworld`](
  https://github.com/zulip/python-zulip-api/tree/master/zulip_bots/zulip_bots/bots/helloworld)
- bot (the actual test is written slightly more compact).
+ bot.
 
-    from __future__ import absolute_import
+    from zulip_bots.test_lib import StubBotTestCase
 
-    from zulip_bots.test_lib import BotTestCase  # The test system library
+    class TestHelpBot(StubBotTestCase):
+        bot_name = "helloworld"  # type: str
 
-    class TestHelloWorldBot(BotTestCase):
+        def test_bot(self) -> None:
-        bot_name = "helloworld"  # The bot's name (should be the name of the bot module to test).
+            dialog = [
+                ('', 'beep boop'),
+                ('help', 'beep boop'),
+                ('foo', 'beep boop'),
+            ]
 
-        def test_bot(self): # A test case (must start with `test`)
+            self.verify_dialog(dialog)
-            # Messages we want to test and the expected bot responses.
-            message_response_pairs = [("", "beep boop"),
-                                      ("foo", "beep boop"),
-                                      ("Hi, my name is abc", "beep boop")]
-            self.check_expected_responses(message_response_pairs)  # Test the bot with our message_response_pair list.
 
-The `helloworld` bot replies with "beep boop" to every message @-mentioning it.
+The `helloworld` bot replies with "beep boop" to every message @-mentioning it.  We
-Note that our helper method `check_expected_responses` adds the @-mention for us - the only
+want our test to verify that the bot **actually** does that.
-thing we need to do is to specify the rest of the message and the expected response. In this
+
-case, we want to assert that the bot always replies with "beep boop". To do so, we specify
+Note that our helper method `verify_dialog` simulates the conversation for us, and
-several test messages ("", "foo", "Hi, my name is abc") and assert that the response is always
+we just need to set up a list of tuples with expected results.
-correct, which for this simple bot, means always sending a reply with the content "beep boop".
+
+The best way to learn about bot tests is to read all the existing tests in the
+`bots` subdirectories.
 
 ### Testing your test
 
@@ -430,8 +432,6 @@ Once you have written a test suite, you want to verify that everything works as
   https://github.com/zulip/python-zulip-api/tree/master/zulip_bots/zulip_bots/bots):
   `tools/test-bots <botname>`
 
-* To run any test: `python -m unittest -v <package.bot_test>`
-
 * To run all bot tests: `tools/test-bots`
 
 ### Advanced testing
@@ -441,30 +441,20 @@ configuration files or interact with third-party APIs.
 *The code for the bot testing library can be found [here](
  https://github.com/zulip/python-zulip-api/blob/master/zulip_bots/zulip_bots/test_lib.py).*
 
-#### Asserting individual messages
-
-    self.assert_bot_response(
-        message = {'content': 'foo'},
-        response = {'content': 'bar'},
-        expected_method='send_reply'
-    )
-
-Use `assert_bot_response()` to test individual messages. Specify additional message
-settings, such as the stream or subject, in the `message` and `response` dicts.
 
 #### Testing bots with config files
 
 Some bots, such as [Giphy](
 https://github.com/zulip/python-zulip-api/tree/master/zulip_bots/zulip_bots/bots/giphy),
-support or require user configuration options to control how the bot works. To test such
+support or require user configuration options to control how the bot works.
-a bot, you can use the following helper method:
 
-    with self.mock_config_info({'entry': 'value'}):
+To test such a bot, you can use the following pattern:
-        # self.assert_bot_response(...)
 
-`mock_config_info()` mocks a bot's config file. All config files are specified in the
+    with self.mock_config_info(dict(api_key=12345)):
-.ini format, with one default section. The dict passed to `mock_config_info()` specifies
+        # self.verify_reply(...)
-the keys and values of that section.
+
+`mock_config_info()` replaces the actual step of reading configuration from the file
+system and gives your test "dummy data" instead.
 
 #### Testing bots with internet access
 
@@ -486,17 +476,6 @@ https://github.com/zulip/python-zulip-api/tree/master/zulip_bots/zulip_bots/bots
 *Tip: You can use [requestb.in](http://requestb.in) or a similar tool to capture payloads from the
 service your bot is interacting with.*
 
-#### Testing bots that specify `initialize()`
-
-Some bots, such as [Giphy](
-https://github.com/zulip/python-zulip-api/tree/master/zulip_bots/zulip_bots/bots/giphy),
-implement an `initialize()` method, which is executed on the startup of the bot. To test
-such a bot, you can call its `initialize()` method with the following helper method:
-
-    self.initialize_bot()
-
-Calling `initialize_bot()` invokes the `initialize()` method specified by the bot.
-
 #### Examples
 
 Check out our [bots](https://github.com/zulip/python-zulip-api/tree/master/zulip_bots/zulip_bots/bots)