test: make vtest.config_new() return one table

The test function used to return 2 values: config and its meta.
The meta can be used to retrieve certain sections of the config by
name, without knowing the automatically generated UUIDs.

The approach with 2 values return appeared to be too clumsy in the
next patches. It would be easier to operate on a single value
which contains meta and cfg in it.

Part of #325

test/luatest_helpers/vtest.lua

@@ -19,13 +19,14 @@ end
 -- anything volatile such as URIs, UUIDs - these are installed at runtime.
 --
 local function config_new(templ)
-    local res = table.deepcopy(templ)
-    local sharding = {}
-    local meta = {replicasets = {}}
-    res.sharding = sharding
+    local cfg = table.deepcopy(templ)
+    local cfg_sharding = {}
+    local meta_sharding = {}
+    local meta = {sharding = meta_sharding}
+    cfg.sharding = cfg_sharding
     for i, replicaset_templ in pairs(templ.sharding) do
         local replicaset_uuid = uuid_next()
-        meta.replicasets[i] = {
+        meta_sharding[i] = {
             uuid = replicaset_uuid
         }
         local replicas = {}
@@ -38,15 +39,16 @@ local function config_new(templ)
             replica.uri = 'storage:storage@'..helpers.instance_uri(replica_name)
             replicas[replica_uuid] = replica
         end
-        sharding[replicaset_uuid] = replicaset
+        cfg_sharding[replicaset_uuid] = replicaset
     end
-    return res, meta
+    return {value = cfg, meta = meta}
 end
 
 --
 -- Build new cluster by a given config.
 --
 local function storage_new(g, cfg)
+    cfg = cfg.value
     if not g.cluster then
         g.cluster = cluster:new({})
     end
@@ -117,6 +119,7 @@ end
 -- Create a new router in the cluster.
 --
 local function router_new(g, name, cfg)
+    cfg = cfg.value
     if not g.cluster then
         g.cluster = cluster:new({})
     end

test/router-luatest/router_test.lua

@@ -4,7 +4,7 @@ local vutil = require('vshard.util')
 local wait_timeout = 120
 
 local g = t.group('router')
-local cluster_cfg, cfg_meta = vtest.config_new({
+local cluster_cfg = vtest.config_new({
     sharding = {
         {
             replicas = {
@@ -206,9 +206,10 @@ g.test_map_callrw_raw = function(g)
             err = err,
         }
     end, {wait_timeout})
+    local cfg_meta = cluster_cfg.meta
     local expected = {
-        [cfg_meta.replicasets[1].uuid] = {{1, 3}},
-        [cfg_meta.replicasets[2].uuid] = {{2, 3}},
+        [cfg_meta.sharding[1].uuid] = {{1, 3}},
+        [cfg_meta.sharding[2].uuid] = {{2, 3}},
     }
     t.assert_equals(res.val, expected, 'map callrw success')
     t.assert_equals(res.map_type, 'userdata', 'values are msgpacks')
@@ -226,7 +227,7 @@ g.test_map_callrw_raw = function(g)
                                         return_raw = true})
     end, {wait_timeout})
     expected = {
-        [cfg_meta.replicasets[1].uuid] = {{1}},
+        [cfg_meta.sharding[1].uuid] = {{1}},
     }
     t.assert_equals(res, expected, 'map callrw without one value success')
     --
@@ -248,7 +249,7 @@ g.test_map_callrw_raw = function(g)
         type = 'ClientError',
         message = 'map_err'
     }, 'error object')
-    t.assert_equals(err_uuid, cfg_meta.replicasets[2].uuid, 'error uuid')
+    t.assert_equals(err_uuid, cfg_meta.sharding[2].uuid, 'error uuid')
     --
     -- Cleanup.
     --