test: add tests for memcached module api

Needed for #96

test/common/module_api.test.lua

@@ -0,0 +1,69 @@
+#!/usr/bin/env tarantool
+
+local socket = require('socket')
+local tap = require('tap')
+package.cpath = './?.so;' .. package.cpath
+local memcached = require('memcached')
+local test = tap.test('memcached module api')
+
+local function is_port_open(port)
+    local sock, _ = socket.tcp_connect('127.0.0.1', port)
+    return sock:sysconnect(0, port) and true or false
+end
+
+if type(box.cfg) == 'function' then
+    box.cfg{
+        wal_mode = 'none',
+        memtx_memory = 100 * 1024 * 1024,
+    }
+    box.schema.user.grant('guest', 'read,write,execute', 'universe')
+end
+
+test:plan(13)
+
+test:is(#memcached.server, 0, 'memcached.server is empty')
+
+-- memcached.create(): instance 1
+
+local mc_1_port = 11211
+local mc_1_name = 'memcached_1_xxx'
+local mc_1_space_name = 'memcached_xxx_1_space'
+
+local mc_1 = memcached.create(mc_1_name, tostring(mc_1_port), {
+    space_name = mc_1_space_name
+})
+test:isnt(mc_1, nil, '1st memcached instance object is not nil')
+test:is(is_port_open(mc_1_port), true, '1st memcached instance is started')
+
+-- memcached.create(): instance 2
+
+local mc_2_port = 11212
+local mc_2_name = 'memcached_2_xxx'
+local mc_2_space_name = 'memcached_2_xxx_space'
+
+local mc_2 = memcached.create(mc_2_name, tostring(mc_2_port), {
+    space_name = mc_2_space_name
+})
+test:isnt(mc_2, nil, '2nd memcached instance object is not nil')
+test:is(is_port_open(mc_2_port), true, '2nd memcached instance is started')
+
+-- memcached.server
+
+test:istable(memcached.server, 'type of memcached.server is a table')
+test:is(#memcached.server, 0, 'memcached.server is empty')
+
+-- memcached.get(): instance 1
+
+local instance_1_info = memcached.get(mc_1_name)
+test:is(instance_1_info.name, mc_1.name, 'memcached.get(): name of instance 1 is correct')
+test:is(instance_1_info.space_name, mc_1.space_name, 'memcached.get(): space name of instance 1 is correct')
+test:is(instance_1_info.space.id, mc_1.space.id, 'memcached.get(): space id of instance 1 is correct')
+
+-- memcached.get(): instance 2
+
+local instance_2_info = memcached.get(mc_2_name)
+test:is(instance_2_info.name, mc_2.name, 'memcached.get(): name of instance 2 is correct')
+test:is(instance_2_info.space_name, mc_2.space_name, 'memcached.get(): space name of instance 2 is correct')
+test:is(instance_2_info.space.id, mc_2.space.id, 'memcached.get(): space id of instance 2 is correct')
+
+os.exit(test:check() and 0 or 1)