patch 8.0.0124
Problem:    Internal error for assert_inrange(1, 1).
Solution:   Adjust number of allowed arguments. (Dominique Pelle)
diff --git a/src/testdir/test_assert.vim b/src/testdir/test_assert.vim
index 0ab664a..25630f2 100644
--- a/src/testdir/test_assert.vim
+++ b/src/testdir/test_assert.vim
@@ -117,6 +117,8 @@
   call assert_inrange(5, 7, 8)
   call assert_match("Expected range 5 - 7, but got 8", v:errors[0])
   call remove(v:errors, 0)
+
+  call assert_fails('call assert_inrange(1, 1)', 'E119:')
 endfunc
 
 func Test_user_is_happy()