lua: Fix tests to work in strict mode

tests/lua/test_clang.lua

-require("test_helper")
-
-TestClang = {}
+local suite = require("test_helper")
+local TestClang = {}
 
 function TestClang:test_probe_read1()
   local text = [[
@@ -329,4 +328,4 @@ function TestClang:test_syntax_error()
     BPF, {text=[[int failure(void *ctx) { if (); return 0; }]]})
 end
 
-os.exit(LuaUnit.run())
+suite("TestClang", TestClang)

tests/lua/test_dump.lua

-require("test_helper")
+local suite = require("test_helper")
+local TestDump = {}
 
-function test_dump_func()
+function TestDump:test_dump_func()
   local raw = "\xb7\x00\x00\x00\x01\x00\x00\x00\x95\x00\x00\x00\x00\x00\x00\x00"
   local b = BPF:new{text=[[int entry(void) { return 1; }]]}
   assert_equals(b:dump_func("entry"), raw)
 end
 
-os.exit(LuaUnit.run())
+suite("TestDump", TestDump)

tests/lua/test_helper.lua

@@ -12,6 +12,12 @@ USE_EXPECTED_ACTUAL_IN_ASSERT_EQUALS = false
 EXPORT_ASSERT_TO_GLOBALS = true
 require("luaunit")
 
-BCC = require("bcc.init")
-BPF = BCC.BPF
+rawset(_G, "BCC", require("bcc.init"))
+rawset(_G, "BPF", BCC.BPF)
+
 log.enabled = false
+
+return function (name, f)
+  rawset(_G, name, f)
+  os.exit(LuaUnit.run())
+end

tests/lua/test_uprobes.lua

-require("test_helper")
+local suite = require("test_helper")
 local ffi = require("ffi")
+local TestUprobes = {}
 
 ffi.cdef[[
   int getpid(void);
   void malloc_stats(void);
 ]]
 
-TestUprobes = {}
-
 function TestUprobes:test_simple_library()
   local text = [[
 #include <uapi/linux/ptrace.h>
@@ -68,4 +67,4 @@ function TestUprobes:teardown()
   BPF.cleanup_probes()
 end
 
-os.exit(LuaUnit.run())
+suite("TestUprobes", TestUprobes)