[Tarantool-patches] [PATCHv3 2/2] test: move helper functions to separated module in -e assert(false) test

[Artem Starshov]

Functions with timeout transferred to module
test/app-tap/lua/process_timeout.lua for further
using in other tests.

Before this version of test was already done,
but by mistake older version was rebased on
master.

Follows up #4983
---
from https://lists.tarantool.org/pipermail/tarantool-patches/2020-December/021895.html :
"2) No external function currently uses this function.
I suggest removing it from the interface."

I'd like to leave `process_is_alive`, because it's really useful
function, it's already needed in `-e enters interactive mode`
test.

 .../gh-4983-tnt-e-assert-false-hangs.test.lua | 62 +++----------------
 test/app-tap/lua/process_timeout.lua          | 57 +++++++++++++++++
 test/app-tap/suite.ini                        |  2 +-
 3 files changed, 67 insertions(+), 54 deletions(-)
 create mode 100644 test/app-tap/lua/process_timeout.lua

diff --git a/test/app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua b/test/app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua
index d259f37fd..2978a6203 100755
--- a/test/app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua
+++ b/test/app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua
@@ -1,61 +1,17 @@
 #!/usr/bin/env tarantool
 
-local fiber = require('fiber')
-local clock = require('clock')
-local ffi = require('ffi')
-local fio = require('fio')
-local errno = require('errno')
+-- Using io.popen and self written module process_timeout
+-- in presence of the 'popen' built-in module because the
+-- last one isn't available in 1.10
+local process_timeout = require('process_timeout')
 local tap = require('tap')
+local fio = require('fio')
+local ffi = require('ffi')
 
 --
 -- gh-4983: tarantool -e 'assert(false)' hangs
 --
 
--- For process_is_alive.
-ffi.cdef([[
-    int kill(pid_t pid, int sig);
-]])
-
----  Verify whether a process is alive.
-local function process_is_alive(pid)
-    local rc = ffi.C.kill(pid, 0)
-    return rc == 0 or errno() ~= errno.ESRCH
-end
-
---- Returns true if process completed before timeout, false otherwise.
-local function wait_process_completion(pid, timeout)
-    local start_time = clock.monotonic()
-    local process_completed = false
-    while clock.monotonic() - start_time < timeout do
-        if not process_is_alive(pid) then
-            process_completed = true
-            break
-        end
-    end
-    return process_completed
-end
-
---- Open file on reading with timeout.
-local function open_with_timeout(filename, timeout)
-    local fh
-    local start_time = clock.monotonic()
-    while not fh and clock.monotonic() - start_time < timeout do
-        fh = fio.open(filename, {'O_RDONLY'})
-    end
-    return fh
-end
-
---- Try to read from file with timeout with interval.
-local function read_with_timeout(fh, timeout, interval)
-    local data = ''
-    local start_time = clock.monotonic()
-    while #data == 0 and clock.monotonic() - start_time < timeout do
-        data = fh:read()
-        if #data == 0 then fiber.sleep(interval) end
-    end
-    return data
-end
-
 local TARANTOOL_PATH = arg[-1]
 local output_file = fio.abspath('out.txt')
 local line = ('%s -e "assert(false)" > %s 2>&1 & echo $!'):
@@ -73,7 +29,7 @@ local res = tap.test('gh-4983-tnt-e-assert-false-hangs', function(test)
     local pid = tonumber(io.popen(line):read('*line'))
     assert(pid, 'pid of proccess can\'t be recieved')
 
-    local process_completed = wait_process_completion(pid,
+    local process_completed = process_timeout.wait_process_completion(pid,
             process_waiting_timeout)
 
     test:ok(process_completed,
@@ -82,10 +38,10 @@ local res = tap.test('gh-4983-tnt-e-assert-false-hangs', function(test)
     -- Kill process if hangs.
     if not process_completed then ffi.C.kill(pid, 9) end
 
-    local fh = open_with_timeout(output_file, file_open_timeout)
+    local fh = process_timeout.open_with_timeout(output_file, file_open_timeout)
     assert(fh, 'error while opening ' .. output_file)
 
-    local data = read_with_timeout(fh, file_read_timeout, file_read_interval)
+    local data = process_timeout.read_with_timeout(fh, file_read_timeout, file_read_interval)
     test:like(data, 'assertion failed', 'assertion failure is displayed')
 
     fh:close()
diff --git a/test/app-tap/lua/process_timeout.lua b/test/app-tap/lua/process_timeout.lua
new file mode 100644
index 000000000..141fb0e43
--- /dev/null
+++ b/test/app-tap/lua/process_timeout.lua
@@ -0,0 +1,57 @@
+local fiber = require('fiber')
+local clock = require('clock')
+local ffi = require('ffi')
+local fio = require('fio')
+local errno = require('errno')
+
+-- For process_is_alive.
+ffi.cdef([[
+    int kill(pid_t pid, int sig);
+]])
+
+---  Verify whether a process is alive.
+local function process_is_alive(pid)
+    local rc = ffi.C.kill(pid, 0)
+    return rc == 0 or errno() ~= errno.ESRCH
+end
+
+--- Returns true if process completed before timeout, false otherwise.
+local function wait_process_completion(pid, timeout)
+    local start_time = clock.monotonic()
+    local process_completed = false
+    while clock.monotonic() - start_time < timeout do
+        if not process_is_alive(pid) then
+            process_completed = true
+            break
+        end
+    end
+    return process_completed
+end
+
+--- Open file on reading with timeout.
+local function open_with_timeout(filename, timeout)
+    local fh
+    local start_time = clock.monotonic()
+    while not fh and clock.monotonic() - start_time < timeout do
+        fh = fio.open(filename, {'O_RDONLY'})
+    end
+    return fh
+end
+
+--- Try to read from file with timeout with interval.
+local function read_with_timeout(fh, timeout, interval)
+    local data = ''
+    local start_time = clock.monotonic()
+    while #data == 0 and clock.monotonic() - start_time < timeout do
+        data = fh:read()
+        if #data == 0 then fiber.sleep(interval) end
+    end
+    return data
+end
+
+return {
+    process_is_alive = process_is_alive,
+    wait_process_completion = wait_process_completion,
+    open_with_timeout = open_with_timeout,
+    read_with_timeout = read_with_timeout
+}
diff --git a/test/app-tap/suite.ini b/test/app-tap/suite.ini
index 2f16128f9..6e27f88d6 100644
--- a/test/app-tap/suite.ini
+++ b/test/app-tap/suite.ini
@@ -1,7 +1,7 @@
 [default]
 core = app
 description = application server tests (TAP)
-lua_libs = lua/require_mod.lua lua/serializer_test.lua
+lua_libs = lua/require_mod.lua lua/serializer_test.lua lua/process_timeout.lua
 is_parallel = True
 pretest_clean = True
 use_unix_sockets_iproto = True
-- 
2.28.0