Add a test case for filtered replication

This closes #10

Signed-off-by: Alexander Shorin <kxepal@apache.org>

test/couch_replicator_filtered_tests.erl

@@ -0,0 +1,202 @@
+% 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.
+
+-module(couch_replicator_filtered_tests).
+
+-include_lib("couch/include/couch_eunit.hrl").
+-include_lib("couch/include/couch_db.hrl").
+-include_lib("couch_replicator/src/couch_replicator.hrl").
+
+-define(DDOC, {[
+    {<<"_id">>, <<"_design/filter_ddoc">>},
+    {<<"filters">>, {[
+        {<<"testfilter">>, <<"
+            function(doc, req){if (doc.class == 'mammal') return true;}
+        ">>}
+    ]}}
+]}).
+
+setup() ->
+    DbName = ?tempdb(),
+    {ok, Db} = couch_db:create(DbName, [?ADMIN_CTX]),
+    ok = couch_db:close(Db),
+    upload_ddoc(DbName),
+    create_docs(DbName),
+    DbName.
+
+setup(local) ->
+    setup();
+setup(remote) ->
+    {remote, setup()};
+setup({A, B}) ->
+    Ctx = test_util:start_couch([couch_replicator]),
+    Source = setup(A),
+    Target = setup(B),
+    {Ctx, {Source, Target}}.
+
+teardown({remote, DbName}) ->
+    teardown(DbName);
+teardown(DbName) ->
+    ok = couch_server:delete(DbName, [?ADMIN_CTX]),
+    ok.
+
+teardown(_, {Ctx, {Source, Target}}) ->
+    teardown(Source),
+    teardown(Target),
+    ok = application:stop(couch_replicator),
+    ok = test_util:stop_couch(Ctx).
+
+filtered_replication_test_() ->
+    Pairs = [{local, local}, {local, remote},
+             {remote, local}, {remote, remote}],
+    {
+        "Filtered replication tests",
+        {
+            foreachx,
+            fun setup/1, fun teardown/2,
+            [{Pair, fun should_succeed/2}
+             || Pair <- Pairs]
+        }
+    }.
+
+
+should_succeed({From, To}, {_Ctx, {Source, Target}}) ->
+    {ok, RepPid, RepId} = replicate(Source, Target),
+    %% FilteredFun is an Erlang version of following JS function
+    %% function(doc, req){if (doc.class == 'mammal') return true;}
+    FilterFun = fun(_DocId, {Props}) ->
+        couch_util:get_value(<<"class">>, Props) == <<"mammal">>
+    end,
+    {lists:flatten(io_lib:format("~p -> ~p", [From, To])),
+        {inorder, [
+            should_ensure_replication_runs(RepPid),
+            should_compare_databases(Source, Target, FilterFun),
+            should_cancel_replication(RepId, RepPid)
+    ]}}.
+
+should_ensure_replication_runs(RepPid) ->
+    ?_assert(begin
+        ?assertMatch(ok, wait_for_replicator(RepPid)),
+        is_process_alive(RepPid)
+    end).
+
+should_compare_databases({remote, Source}, Target, FilterFun) ->
+    should_compare_databases(Source, Target, FilterFun);
+should_compare_databases(Source, {remote, Target}, FilterFun) ->
+    should_compare_databases(Source, Target, FilterFun);
+should_compare_databases(Source, Target, FilterFun) ->
+    ?_assertEqual(1, begin
+        compare_dbs(Source, Target, FilterFun)
+    end).
+
+should_cancel_replication(RepId, RepPid) ->
+    ?_assertNot(begin
+        ?assertMatch({ok, _}, couch_replicator:cancel_replication(RepId)),
+        is_process_alive(RepPid)
+    end).
+
+compare_dbs(Source, Target, FilterFun) ->
+    {ok, SourceDb} = couch_db:open_int(Source, []),
+    {ok, TargetDb} = couch_db:open_int(Target, []),
+    Fun = fun(FullDocInfo, _, Acc) ->
+        {ok, DocId, SourceDoc} = read_doc(SourceDb, FullDocInfo, ?LINE),
+        case FilterFun(DocId, SourceDoc) of
+            true ->
+                {ok, DocId, TargetDoc} = read_doc(TargetDb, DocId, ?LINE),
+                ?assertEqual(SourceDoc, TargetDoc),
+                {ok, Acc + 1};
+            false ->
+                {ok, Acc}
+        end
+    end,
+    {ok, _, Acc} = couch_db:enum_docs(SourceDb, Fun, 0, []),
+    ok = couch_db:close(SourceDb),
+    ok = couch_db:close(TargetDb),
+    Acc.
+
+read_doc(Db, DocIdOrInfo, Line) ->
+    case couch_db:open_doc(Db, DocIdOrInfo) of
+        {ok, Doc} ->
+            {Props} = couch_doc:to_json_obj(Doc, [attachments]),
+            DocId = couch_util:get_value(<<"_id">>, Props),
+            {ok, DocId, {Props}};
+        Error ->
+            Reason = lists:concat([
+                "Error opening document '", ?b2l(doc_id(DocIdOrInfo)),
+                "' from target: ", couch_util:to_list(Error)]),
+            erlang:error(
+                {assertion_failed,
+                 [{module, ?MODULE}, {line, Line},
+                  {reason, Reason}]})
+    end.
+
+doc_id(#full_doc_info{id = Id}) -> Id;
+doc_id(Id) -> Id.
+
+
+wait_for_replicator(Pid) ->
+    %% since replicator started asynchronously
+    %% we need to wait when it would be in couch_task_status
+    %% we query replicator:details to ensure that do_init happen
+    ?assertMatch({ok, _}, couch_replicator:details(Pid)),
+    ok.
+
+create_docs(DbName) ->
+    {ok, Db} = couch_db:open(DbName, [?ADMIN_CTX]),
+    Doc1 = couch_doc:from_json_obj({[
+        {<<"_id">>, <<"doc1">>},
+        {<<"class">>, <<"mammal">>},
+        {<<"value">>, 1}
+
+    ]}),
+    Doc2 = couch_doc:from_json_obj({[
+        {<<"_id">>, <<"doc2">>},
+        {<<"value">>, 2}
+
+    ]}),
+    Doc3 = couch_doc:from_json_obj({[
+        {<<"_id">>, <<"doc3">>},
+        {<<"class">>, <<"reptiles">>},
+        {<<"value">>, 3}
+
+    ]}),
+    {ok, _} = couch_db:update_docs(Db, [Doc1, Doc2, Doc3]),
+    couch_db:ensure_full_commit(Db),
+    couch_db:close(Db).
+
+
+upload_ddoc(DbName) ->
+    Url = db_url(DbName) ++ "/_design/filter_ddoc",
+    Body = couch_util:json_encode(?DDOC),
+    {ok, 201, _Resp, _Body} = test_request:put(Url, Body),
+    ok.
+
+replicate({remote, Db}, Target) ->
+    replicate(?l2b(db_url(Db)), Target);
+
+replicate(Source, {remote, Db}) ->
+    replicate(Source, ?l2b(db_url(Db)));
+
+replicate(Source, Target) ->
+    RepObject = {[
+        {<<"source">>, Source},
+        {<<"target">>, Target},
+        {<<"continuous">>, true}
+    ]},
+    {ok, Rep} = couch_replicator_utils:parse_rep_doc(RepObject, ?ADMIN_USER),
+    {ok, Pid} = couch_replicator:async_replicate(Rep),
+    {ok, Pid, Rep#rep.id}.
+
+db_url(DbName) ->
+    Addr = config:get("httpd", "bind_address", "127.0.0.1"),
+    Port = integer_to_list(mochiweb_socket_server:get(couch_httpd, port)),
+    "http://" ++ Addr ++ ":" ++ Port ++ "/" ++ ?b2l(DbName).