buffer: Hide one of the asserts from lua parser

src/nvim/buffer.h

@@ -96,7 +96,10 @@ static inline void buf_set_changedtick(buf_T *const buf, const int changedtick)
   assert(changedtick_di != NULL);
   assert(changedtick_di->di_tv.v_type == VAR_NUMBER);
   assert(changedtick_di->di_tv.v_lock == VAR_FIXED);
+  // For some reason formatc does not like the below.
+# ifndef UNIT_TESTING_LUA_PREPROCESSING
   assert(changedtick_di->di_flags == (DI_FLAGS_RO|DI_FLAGS_FIX));
+# endif
   assert(changedtick_di == (dictitem_T *)&buf->changedtick_di);
   assert(&buf->b_changedtick == &buf->changedtick_di.di_tv.vval.v_number);
 #endif

test/unit/helpers.lua

@@ -79,6 +79,13 @@ local function cimport(...)
 
   -- format it (so that the lines are "unique" statements), also filter out
   -- Objective-C blocks
+  if os.getenv('NVIM_TEST_PRINT_I') == '1' then
+    local lnum = 0
+    for line in body:gmatch('[^\n]+') do
+      lnum = lnum + 1
+      print(lnum, line)
+    end
+  end
   body = formatc(body)
   body = filter_complex_blocks(body)
 

test/unit/preprocess.lua

@@ -124,6 +124,7 @@ function Gcc:init_defines()
   self:define('_GNU_SOURCE')
   self:define('INCLUDE_GENERATED_DECLARATIONS')
   self:define('UNIT_TESTING')
+  self:define('UNIT_TESTING_LUA_PREPROCESSING')
   -- Needed for FreeBSD
   self:define('_Thread_local', nil, '')
   -- Needed for macOS Sierra