test: introduce routine to build error message

LuaJIT modules yield the plain errors, but LuaJIT binary adds 'luajit:'
prefix to it, so 411-luajit.t test in lua-Harness suite expects the
error message with the aforementioned prefix in the corresponding
assertions. At the same time, Tarantool doesn't prepend errors produced
by the LuaJIT module with anything.

To tweak the pattern to be used within the 411-luajit.t chunk, the
auxiliary error building function is introduced in this patch.

Reviewed-by: Maxim Kokryashkin <[email protected]>
Reviewed-by: Sergey Kaplun <[email protected]>
Signed-off-by: Sergey Kaplun <[email protected]>

test/lua-Harness-tests/411-luajit.t

@@ -31,6 +31,15 @@ if not jit or ujit or _TARANTOOL then
     skip_all("only with LuaJIT")
 end
 
+-- XXX: Unfortunately, Lua patterns do not support optional
+-- capture groups, so the helper below implements poor man's
+-- optional capture groups for the patterns matching LuaJIT CLI
+-- error messages.
+local function errbuild(message)
+    local errprefix = _TARANTOOL and "" or "[^:]+: "
+    return table.concat({"^", errprefix, message})
+end
+
 local lua = _retrieve_progname()
 
 if not pcall(io.popen, lua .. [[ -e "a=1"]]) then
@@ -158,13 +167,13 @@ f = io.popen(cmd)
 if compiled_with_jit then
     equals(f:read'*l', 'Hello World', "-jon")
 else
-    matches(f:read'*l', "^[^:]+: JIT compiler permanently disabled by build option", "no jit")
+    matches(f:read'*l', errbuild("JIT compiler permanently disabled by build option"), "no jit")
 end
 f:close()
 
 cmd = lua .. " -j bad hello-411.lua 2>&1"
 f = io.popen(cmd)
-matches(f:read'*l', "^[^:]+: unknown luaJIT command or jit%.%* modules not installed", "-j bad")
+matches(f:read'*l', errbuild("unknown luaJIT command or jit%.%* modules not installed"), "-j bad")
 f:close()
 
 if compiled_with_jit then
@@ -190,12 +199,12 @@ if compiled_with_jit then
 
     cmd = lua .. " -O+bad hello-411.lua 2>&1"
     f = io.popen(cmd)
-    matches(f:read'*l', "^[^:]+: unknown or malformed optimization flag '%+bad'", "-O+bad")
+    matches(f:read'*l', errbuild("unknown or malformed optimization flag '%+bad'"), "-O+bad")
     f:close()
 else
     cmd = lua .. " -O0 hello-411.lua 2>&1"
     f = io.popen(cmd)
-    matches(f:read'*l', "^[^:]+: attempt to index a nil value")
+    matches(f:read'*l', errbuild("attempt to index a nil value"))
     f:close()
 end