Github user kxepal commented on a diff in the pull request:
https://github.com/apache/couchdb-chttpd/pull/10#discussion_r21059264
--- Diff: test/chttpd_handler_callback_test.erl ---
@@ -0,0 +1,266 @@
+%% Licensed under the Apache License, Version 2.0 (the "License"); you
may not
+%% use this file except in compliance with the License. You may obtain a
copy of
+%% the License at
+%%
+%% http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing,
software
+%% distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT
+%% WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the
+%% License for the specific language governing permissions and limitations
under
+%% the License.
+%%
+%% @doc
+%% These whitebox tests call the endpoints that are implemented by dynamic
funs,
+%% which replace the previously hardwired handlers, with a dynamically
created
+%% module. This test mocks everything except the proper relationship
between
+%% handler function clause and returned fun. The handler functions are
called
+%% directly.
+%%
+%% This can look like mocks testing themselves. In this case, in other
words:
+%% think of the former url_handler function in chttpd.erl: The relationship
+%% between a function clause and the specific returned fun() is exactly
what is
+%% established by the dynamically created module. And it's precisely what
this
+%% test verifies, for every endpoint.
+%%
+%% This test was part of chttpd-cloudant dbcore-2.7.7, verifying the
original
+%% hardcoded endpoints. It has since been reworked but remains functionally
+%% mostly identical; the config source and processing has been replaced.
+
+-module(chttpd_handler_callback_test).
+
+-include_lib("eunit/include/eunit.hrl").
+
+all_test_() ->
+ io:format(user, "~nEndpoint handler callbacks:~n", []),
+ {setup,
+ fun() -> chttpd_handler:build(test_cfg()) end,
+ [
+
+ % url handlers
+ fun() ->
+ assertReturns("", chttpd_misc, handle_welcome_req)
+ end,
+ fun() ->
+ assertReturns("favicon.ico", chttpd_misc, handle_favicon_req)
+ end,
+ fun() ->
+ assertReturns("_utils", chttpd_misc, handle_utils_dir_req)
+ end,
+ fun() ->
+ assertReturns("_all_dbs", chttpd_misc, handle_all_dbs_req)
+ end,
+ fun() ->
+ assertReturns("_active_tasks", chttpd_misc, handle_task_status_req)
+ end,
+ fun() ->
+ assertReturns("_config", chttpd_misc, handle_config_req)
+ end,
+ fun() ->
+ assertReturns("_reload_query_servers", chttpd_misc,
+ handle_reload_query_servers_req)
+ end,
+ fun() ->
+ assertReturns("_replicate", chttpd_misc, handle_replicate_req)
+ end,
+ fun() ->
+ assertReturns("_uuids", chttpd_misc, handle_uuids_req)
+ end,
+ fun() ->
+ assertReturns("_sleep", chttpd_misc, handle_sleep_req)
+ end,
+ fun() ->
+ assertReturns("_session", chttpd_auth, handle_session_req)
+ end,
+ fun() ->
+ assertReturns("_oauth", couch_httpd_oauth, handle_oauth_req)
+ end,
+ fun() ->
+ assertReturns("_up", chttpd_misc, handle_up_req)
+ end,
+ fun() ->
+ assertReturns("_membership", mem3_httpd, handle_membership_req)
+ end,
+ fun() ->
+ assertReturns("_db_updates", global_changes_httpd,
+ handle_global_changes_req) end,
+ fun() ->
+ assertReturns("anything", chttpd_db, handle_request)
+ end,
+
+ % Test the tests: if the final target function is missing, the call
must
+ % fail, with any parameter. All parameters are valid.
+ fun() ->
+ assertUnmockedFails("", chttpd_misc)
+ end,
+ fun() ->
+ assertUnmockedFails("favicon.ico", chttpd_misc)
+ end,
+ fun() ->
+ assertUnmockedFails(anything, chttpd_db)
+ end,
+
+
+ % db url handler tests
+
+ fun() ->
+ assertReturns(db_url_handlers, <<"_view_cleanup">>, chttpd_db,
+ handle_view_cleanup_req, 2) end,
+ fun() ->
+ assertReturns(db_url_handlers, <<"_compact">>, chttpd_db,
+ handle_compact_req, 2)
+ end,
+ fun() ->
+ assertReturns(db_url_handlers, <<"_design">>, chttpd_db,
+ handle_design_req, 2)
+ end,
+ fun() ->
+ assertReturns(db_url_handlers, <<"_temp_view">>, chttpd_view,
+ handle_temp_view_req, 2) end,
+ fun() ->
+ assertReturns(db_url_handlers, <<"_changes">>, chttpd_db,
+ handle_changes_req, 2) end,
+ fun() ->
+ assertReturns(db_url_handlers, <<"_shards">>, mem3_httpd,
+ handle_shards_req, 2) end,
+
+ % Test the test: when the final target function is missing, the Fun
call
+ % must fail, with any argument, including valid ones.
+ fun() ->
+ assertUnmockedFails(db_url_handlers, <<"_view_cleanup">>,
chttpd_db, 2)
+ end,
+
+ % Test the test: when the argument is unknown, the Fun call must fail.
+ fun() ->
+ assertUnknownFails(db_url_handlers, <<"_something">>)
+ end,
+
+
+ % design url handler tests
+
+ fun() ->
+ assertReturns(design_url_handlers, <<"_view">>, chttpd_view,
+ handle_view_req, 3) end,
+ fun() ->
+ assertReturns(design_url_handlers, <<"_show">>, chttpd_show,
+ handle_doc_show_req, 3) end,
+ fun() ->
+ assertReturns(design_url_handlers, <<"_list">>, chttpd_show,
+ handle_view_list_req, 3) end,
+ fun() ->
+ assertReturns(design_url_handlers, <<"_update">>, chttpd_show,
+ handle_doc_update_req, 3) end,
+ fun() ->
+ assertReturns(design_url_handlers, <<"_info">>, chttpd_db,
+ handle_design_info_req, 3) end,
+ fun() ->
+ assertReturns(design_url_handlers, <<"_rewrite">>, chttpd_rewrite,
+ handle_rewrite_req, 3) end,
+
+ % Test the test: when the final target function is missing, the Fun
call
+ % must fail with any argument, including valid ones.
+ fun() ->
+ assertUnmockedFails(design_url_handlers, <<"_view">>, chttpd_view,
3)
+ end,
+ % Test the test: when the argument is unknown, the Fun call must fail.
+ fun() ->
+ assertUnknownFails(design_url_handlers, <<"_something">>)
+ end]}.
+
+
+%% Call the dynamic function with a parameter known to trigger a specific
+%% clause. Then call the returned fun and get confirmation that this called
+%% the right implicit fun, which is mocked, and returns the expected tuple.
+assertReturns(Endpoint, M, F) ->
+ meck:new(M, [passthrough, non_strict]),
+ try
+ io:format(user, "~-47...s ", [Endpoint]),
+ meck:expect(M, F, fun(X) -> {return, Endpoint, X} end),
+ Fun = chttpd_handler:url_handler(Endpoint),
+ ?assertEqual({return, Endpoint, x}, Fun(x))
--- End diff --
Please don't call ?assert from eunit tests generator: this makes debugging
extremely hard:
```
chttpd_handler_callback_test:
all_test_.................................................. *failed*
::error:function_clause
in function chttpd_db:handle_request/1
called as handle_request(x)
in call from chttpd_handler_callback_test:'-assertReturns/3-fun-1-'/2
in call from chttpd_handler_callback_test:assertReturns/3
chttpd_handler_callback_test:
all_test_...favicon.ico.................................... [0.070 s] ok
chttpd_handler_callback_test:
all_test_..._utils......................................... [0.071 s] ok
```
since ?assert* macros checks expression in runtime while ?_assert* doing
this when eunit really starts to run the tests + it provides better traceback.
See how couchdb-couch tests are done.
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