test: add app-tap/console_lua test

Test multireturn in lua output mode and lack of a parameter in '\set
output <...>' command.

Co-developed-by: Alexander Turenko <alexander.turenko@tarantool.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Reviewed-by: Alexander Turenko <alexander.turenko@tarantool.org>
(cherry picked from commit cdf502c6)

test/app-tap/console_lua.test.lua

+#!/usr/bin/env tarantool
+--
+-- vim: ts=4 sw=4 et
+
+local console = require('console')
+local socket = require('socket')
+local tap = require('tap')
+local fio = require('fio')
+
+local EOL = ';'
+local CONSOLE_SOCKET = 'console-lua.sock'
+
+--
+-- Set Lua output mode.
+local function set_lua_output(client, opts)
+    local opts = opts or {}
+    local mode = opts.block and 'lua,block' or 'lua'
+    client:write(('\\set output %s\n'):format(mode))
+    assert(client:read(EOL), 'true' .. EOL, 'set lua output mode')
+end
+
+--
+-- Start console and setup a client.
+local function start_console()
+    -- Make sure not stale sockets are
+    -- left from previous runs.
+    fio.unlink(CONSOLE_SOCKET)
+
+    local server = console.listen('unix/:./' .. CONSOLE_SOCKET)
+    assert(server ~= nil, 'console.listen started')
+
+    local client = socket.tcp_connect('unix/', CONSOLE_SOCKET)
+    assert(client ~= nil, 'connect to console')
+    local handshake = client:read({chunk = 128})
+    assert(string.match(handshake, '^Tarantool .*console') ~= nil, 'handshake')
+
+    -- Switch to Lua output mode.
+    set_lua_output(client, {block = false})
+    return server, client
+end
+
+--
+-- Disconnect from console and stop it.
+local function stop_console(server, client)
+    client:close()
+    server:close()
+
+    local new_client = socket.tcp_connect('unix/', CONSOLE_SOCKET)
+    assert(new_client == nil, 'console.listen stopped')
+end
+
+--
+-- Give `{x}` for a scalar `x`, just `x` otherwise.
+local function totable(x)
+    return type(x) == 'table' and x or {x}
+end
+
+--
+-- Execute a list of statements, show requests and responses.
+local function execute_statements(test, client, statements, name)
+    test:test(name, function(test)
+        test:plan(2 * #statements)
+
+        for _, stmt in ipairs(statements) do
+            local request = stmt .. '\n'
+            local res = client:write(request)
+            test:ok(res ~= nil, ('-> [[%s]]'):format(request:gsub('\n', '\\n')))
+
+            local response = client:read(EOL)
+            test:ok(response ~= nil and response:endswith(EOL),
+                    ('<- [[%s]]'):format(response))
+        end
+    end)
+end
+
+--
+-- Execute a statement and verify its response.
+local function execute_and_verify(test, client, input, exp_output, name)
+    test:test(name, function(test)
+        test:plan(2)
+
+        local res = client:write(input .. '\n')
+        test:ok(res ~= nil, ('-> [[%s]]'):format(input))
+
+        local exp = exp_output .. EOL
+        local res = client:read(EOL)
+        test:is(res, exp, ('<- [[%s]]'):format(exp:gsub('\n', '\\n')))
+    end)
+end
+
+--
+-- Test cases table:
+-- @name:       Name of the test, mandatory
+-- @prepare:    Preparation script, optional
+-- @opts:       Console options, optional
+-- @input:      Input statement to execute, mandatory
+-- @expected:   Expected results to compare with, mandatory
+-- @cleanup:    Cleanup script to run after the test, optional
+local cases = {
+    {
+        name        = 'multireturn line mode',
+        prepare     = 'a = {1, 2, 3}',
+        opts        = {block = false},
+        input       = '1, 2, nil, a',
+        expected    = '1, 2, box.NULL, {1, 2, 3}',
+        cleanup     = 'a = nil',
+    }, {
+        name        = 'multireturn block mode',
+        prepare     = 'a = {1, 2, 3}',
+        opts        = {block = true},
+        input       = '1, 2, nil, a',
+        expected    = '1, 2, box.NULL, {\n  1,\n  2,\n  3\n}',
+        cleanup     = 'a = nil',
+    }, {
+        name        = 'trailing nils, line mode',
+        opts        = {block = false},
+        input       = '1, nil, nil, nil',
+        expected    = '1, box.NULL, box.NULL, box.NULL',
+    }, {
+        name        = 'trailing nils, block mode',
+        opts        = {block = true},
+        input       = '1, nil, nil, nil',
+        expected    = '1, box.NULL, box.NULL, box.NULL',
+    }, {
+        name        = 'empty output',
+        input       = '\\set output',
+        expected    = '"Specify output format: lua or yaml."',
+    }
+}
+
+local test = tap.test('console-lua')
+test:plan(#cases)
+
+local server, client = start_console()
+
+for _, case in ipairs(cases) do
+    test:test(case.name, function(test)
+        test:plan(3)
+
+        execute_statements(test, client, totable(case.prepare), 'prepare')
+
+        set_lua_output(client, case.opts)
+        execute_and_verify(test, client, case.input, case.expected, 'run')
+
+        execute_statements(test, client, totable(case.cleanup), 'cleanup')
+    end)
+end
+
+stop_console(server, client)
+
+os.exit(test:check() and 0 or 1)