1 files changed, 20 insertions, 7 deletions
diff --git a/test/unit/mbyte_spec.lua b/test/unit/mbyte_spec.lua
index 9b2415a93f..3e65537270 100644
--- a/test/unit/mbyte_spec.lua
+++ b/test/unit/mbyte_spec.lua
@@ -1,9 +1,11 @@
-local helpers = require("test.unit.helpers")
+local helpers = require("test.unit.helpers")(after_each)
+local itp = helpers.gen_itp(it)
 
 local ffi     = helpers.ffi
 local eq      = helpers.eq
 
 local mbyte = helpers.cimport("./src/nvim/mbyte.h")
+local charset = helpers.cimport('./src/nvim/charset.h')
 
 describe('mbyte', function()
 
@@ -26,7 +28,7 @@ describe('mbyte', function()
   before_each(function()
   end)
 
-  it('utf_ptr2char', function()
+  itp('utf_ptr2char', function()
     -- For strings with length 1 the first byte is returned.
     for c = 0, 255 do
       eq(c, mbyte.utf_ptr2char(to_string({c, 0})))
@@ -41,10 +43,21 @@ describe('mbyte', function()
     -- Sequences with more than four bytes
   end)
 
+  for n = 0, 0xF do
+    itp(('utf_char2bytes for chars 0x%x - 0x%x'):format(n * 0x1000, n * 0x1000 + 0xFFF), function()
+      local char_p = ffi.typeof('char[?]')
+      for c = n * 0x1000, n * 0x1000 + 0xFFF do
+        local p = char_p(4, 0)
+        mbyte.utf_char2bytes(c, p)
+        eq(c, mbyte.utf_ptr2char(p))
+        eq(charset.vim_iswordc(c), charset.vim_iswordp(p))
+      end
+    end)
+  end
 
   describe('utfc_ptr2char_len', function()
 
-    it('1-byte sequences', function()
+    itp('1-byte sequences', function()
       local pcc = to_intp()
       for c = 0, 255 do
         eq(c, mbyte.utfc_ptr2char_len(to_string({c}), pcc, 1))
@@ -52,7 +65,7 @@ describe('mbyte', function()
       end
     end)
 
-    it('2-byte sequences', function()
+    itp('2-byte sequences', function()
       local pcc = to_intp()
       -- No combining characters
       eq(0x007f, mbyte.utfc_ptr2char_len(to_string({0x7f, 0x7f}), pcc, 2))
@@ -76,7 +89,7 @@ describe('mbyte', function()
       eq(0, pcc[0])
     end)
 
-    it('3-byte sequences', function()
+    itp('3-byte sequences', function()
       local pcc = to_intp()
 
       -- No second UTF-8 character
@@ -108,7 +121,7 @@ describe('mbyte', function()
       eq(0, pcc[0])
     end)
 
-    it('4-byte sequences', function()
+    itp('4-byte sequences', function()
       local pcc = to_intp()
 
       -- No following combining character
@@ -145,7 +158,7 @@ describe('mbyte', function()
       eq(0, pcc[0])
     end)
 
-    it('5+-byte sequences', function()
+    itp('5+-byte sequences', function()
       local pcc = to_intp()
 
       -- No following combining character