unittests: Do not use which, add data to paths.lua.in instead

test/config/paths.lua.in

@@ -8,6 +8,15 @@ end
 module.test_include_path = "${CMAKE_BINARY_DIR}/test/includes/post"
 module.test_libnvim_path = "${TEST_LIBNVIM_PATH}"
 module.test_source_path = "${CMAKE_SOURCE_DIR}"
+module.test_lua_prg = "${LUA_PRG}"
+module.test_luajit_prg = ""
+if module.test_luajit_prg == '' then
+  if module.test_lua_prg:sub(-6) == 'luajit' then
+    module.test_luajit_prg = module.test_lua_prg
+  else
+    module.test_luajit_prg = nil
+  end
+end
 table.insert(module.include_paths, "${CMAKE_BINARY_DIR}/include")
 
 return module

test/helpers.lua

@@ -216,8 +216,11 @@ local function which(exe)
   local pipe = io.popen('which ' .. exe, 'r')
   local ret = pipe:read('*a')
   pipe:close()
-  assert(ret:sub(-1) == '\n')
+  if ret == '' then
-  return ret:sub(1, -2)
+    return nil
+  else
+    return ret:sub(1, -2)
+  end
 end
 
 return {

test/unit/helpers.lua

@@ -520,7 +520,7 @@ local function gen_itp(it)
         if not err then
           if allow_failure then
             io.stderr:write('Errorred out:\n' .. tostring(emsg) .. '\n')
-            os.execute([[sh -c "source .ci/common/test.sh ; check_core_dumps --delete \"\$(which luajit)\""]])
+            os.execute([[sh -c "source .ci/common/test.sh ; check_core_dumps --delete \"]] .. Paths.test_luajit_prg .. [[\""]])
           else
             error(emsg)
           end
@@ -560,7 +560,7 @@ local module = {
 return function(after_each)
   if after_each then
     after_each(function()
-      check_cores(which('luajit'))
+      check_cores(Paths.test_luajit_prg)
     end)
   end
   return module