[Tarantool-patches] [PATCH luajit v3 1/2] test: refactored utils.exec.makecmd

[Evgeniy Temirgaleev via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

From: Temir Galeev <temir.galeev@bk.ru>

The 'utils.exec.makecmd()' was refactored to allow executing of the
arbitrary commands. Also, the diagnostic messages may be enabled
if the test object is supplied. See the example below.

Initially this patch was prepared for tests in the follows up
'Improve CLI signal handling on POSIX' patch. After the test
simplification the shell script helper was wiped out, but the
refactoring was already done.

How to use new 'utils.exec.makecmd_exec()' to run arbitrary
shell script:

```
local tap = require('tap')
local test = tap.test('example')
local utils = require('utils')
local script = utils.exec.makecmd_exec('/bin/sh', {
  args = {'-c'},
  redirect = '2>&1',
  t = test, -- shows cmd and it's output for diagnostic
})

test:plan(2)
local output
output = script("'echo 1'")
test:is(output, '1')
output = script("'echo 2'")
test:is(output, '23') -- see the on-failure output
test:done(true)
```
---
 test/tarantool-tests/utils/exec.lua | 56 +++++++++++++++++++++++------
 1 file changed, 45 insertions(+), 11 deletions(-)

diff --git a/test/tarantool-tests/utils/exec.lua b/test/tarantool-tests/utils/exec.lua
index 49f8ef06..b435e084 100644
--- a/test/tarantool-tests/utils/exec.lua
+++ b/test/tarantool-tests/utils/exec.lua
@@ -43,33 +43,67 @@ local function makeenv(tabenv)
   return table.concat(flatenv, ' ')
 end
 
--- <makecmd> creates a command that runs %testname%/script.lua by
--- <LUAJIT_TEST_BINARY> with the given environment, launch options
--- and CLI arguments. The function yields an object (i.e. table)
--- with the aforementioned parameters. To launch the command just
--- call the object.
-function M.makecmd(arg, opts)
+-- <makecmd_exec> creates a command that runs given binary
+-- with the given environment, launch options and zero or
+-- more permanent arguments.
+-- The function yields an object (i.e. table) with the
+-- aforementioned parameters. To launch the command just call
+-- the object. Additional arguments which may vary from call
+-- to call are the `__call` args.
+-- Pass tap.test() object as opts.t for diagnostic.
+function M.makecmd_exec(bin, opts)
+  assert(type(bin) == 'string')
+  assert(opts == nil or type(opts) == 'table')
+  local perm_args = opts and opts.args or {}
+  assert(type(perm_args) == 'table')
   return setmetatable({
-    LUABIN = M.luacmd(arg),
-    SCRIPT = opts and opts.script or arg[0]:gsub('%.test%.lua$', '/script.lua'),
+    BIN = bin,
     ENV = opts and makeenv(opts.env) or '',
     REDIRECT = opts and opts.redirect or '',
+    PERMARGS = (' %s'):rep(#perm_args):format(unpack(perm_args)),
+    t = opts and opts.t,
   }, {
     __call = function(self, ...)
       -- This line just makes the command for <io.popen> by the
       -- following steps:
       -- 1. Replace the placeholders with the corresponding values
-      --    given to the command constructor (e.g. script, env).
+      --    given to the command constructor (e.g. bin, env).
       -- 2. Join all CLI arguments given to the __call metamethod.
       -- 3. Concatenate the results of step 1 and step 2 to obtain
       --    the resulting command.
-      local cmd = ('<ENV> <LUABIN> <REDIRECT> <SCRIPT>'):gsub('%<(%w+)>', self)
+      local cmd = ('<ENV> <BIN> <REDIRECT> <PERMARGS>'):gsub('%<(%w+)>', self)
                   .. (' %s'):rep(select('#', ...)):format(...)
+      if self.t ~= nil then self.t:diag('cmd: '..cmd) end
       -- Trim both leading and trailing whitespace from the output
       -- produced by the child process.
-      return io.popen(cmd):read('*all'):gsub('^%s+', ''):gsub('%s+$', '')
+      local output = io.popen(cmd):
+        read('*all'):gsub('^%s+', ''):gsub('%s+$', '')
+      if self.t ~= nil then self.t:diag('output: '..output) end
+      return output
     end
   })
 end
 
+-- Makes a file name for running test's data file in
+-- '%testname%' directory.
+function M.test_data(arg, name)
+  local fname, matches = arg[0]:gsub('%.test%.lua$', '/'..name)
+  assert(matches == 1, 'unexpected test filename')
+  return fname
+end
+
+-- <makecmd> creates a command that runs %testname%/script.lua by
+-- <LUAJIT_TEST_BINARY> with the given environment, launch options
+-- and CLI arguments.
+function M.makecmd(arg, opts)
+  local luabin = M.luacmd(arg)
+  local script = opts and opts.script or M.test_data(arg, 'script.lua')
+  return M.makecmd_exec(luabin, {
+    env = opts and opts.env or nil,
+    redirect = opts and opts.redirect or nil,
+    args = {script},
+    t = opts and opts.t or nil,
+  })
+end
+
 return M
-- 
2.49.0