Raise error in wait_for_condition when server is terminated

Raise an error in the `Server:wait_for_condition()` function when
the server process is terminated. This is useful to not wait for timeout,
for example, when a server fails to start due to bad configuration.

Resolves #224, #275

Author: Oleg Chaplashkin

CHANGELOG.md

@@ -47,6 +47,9 @@
   via the corresponding upvalue.
 - Add new function `tarantool.skip_if_not_enterprise`.
 - Raise an error when non-array arguments passed to the `server:exec()`.
+- Raise an error in the `Server:wait_for_condition()` function when
+  the server process is terminated. This is useful to not wait for timeout, for example,
+  when a server fails to start due to bad configuration.
 
 ## 0.5.7
 

luatest/server.lua

@@ -315,10 +315,14 @@ function Server:restart(params, opts)
 end
 
 -- Wait until the given condition is `true` (anything except `false` and `nil`).
--- Throws an error when timeout exceeds.
+-- Throws an error when the server process is terminated or timeout exceeds.
 local function wait_for_condition(cond_desc, server, func, ...)
     local deadline = clock.time() + WAIT_TIMEOUT
     while true do
+        if not server.process:is_alive() then
+            error(('Process is terminated when waiting for "%s" condition for server (alias: %s, workdir: %s, pid: %d)')
+                :format(cond_desc, server.alias, fio.basename(server.workdir), server.process.pid))
+        end
         if func(...) then
             return
         end
@@ -343,9 +347,12 @@ function Server:stop()
 
     if self.process then
         self.process:kill()
-        wait_for_condition('process is terminated', self, function()
+        local ok, err = pcall(wait_for_condition, 'process is terminated', self, function()
             return not self.process:is_alive()
         end)
+        if not ok and not err:find('Process is terminated when waiting for') then
+            error(err)
+        end
         log.debug('Killed server process PID ' .. self.process.pid)
         self.process = nil
     end

test/server_test.lua

@@ -301,3 +301,32 @@ g.test_server_start_with_coverage_enabled = function()
         server:exec(function() return box.info.status end), 'running'
     )
 end
+
+g.test_wait_when_server_is_not_running_by_bad_option = function()
+    local s1 = Server:new({
+        box_cfg = {
+            bad_option = 'bad'
+        }
+    })
+    local s2 = Server:new({
+        box_cfg = {
+            replication = {
+                'bad_uri'
+            }
+        }
+    })
+
+    local expected_msg = 'Process is terminated when waiting for "server is ready"'
+
+    local status, msg = pcall(Server.start, s1)
+    t.assert_equals(status, false)
+    t.assert_str_contains(msg, expected_msg)
+    t.assert_equals(s1.process:is_alive(), false)
+    s1:clean()
+
+    status, msg = pcall(Server.start, s2)
+    t.assert_equals(status, false)
+    t.assert_str_contains(msg, expected_msg)
+    t.assert_equals(s2.process:is_alive(), false)
+    s2:clean()
+end