tests: Add missing test cases

src/nvim/api/vim.c

@@ -971,6 +971,11 @@ Dictionary nvim_parse_expression(String expr, String flags, Boolean highlight,
     switch (flags.data[i]) {
       case 'm': { pflags |= kExprFlagsMulti; break; }
       case 'E': { pflags |= kExprFlagsDisallowEOC; break; }
+      case NUL: {
+        api_set_error(err, kErrorTypeValidation, "Invalid flag: '\\0' (%u)",
+                      (unsigned)flags.data[i]);
+        return (Dictionary)ARRAY_DICT_INIT;
+      }
       default: {
         api_set_error(err, kErrorTypeValidation, "Invalid flag: '%c' (%u)",
                       flags.data[i], (unsigned)flags.data[i]);
@@ -995,6 +1000,7 @@ Dictionary nvim_parse_expression(String expr, String flags, Boolean highlight,
       &pstate, parser_simple_get_line, &plines_p, colors_p);
   ExprAST east = viml_pexpr_parse(&pstate, pflags);
 
+  // FIXME add parse_length key
   const size_t ret_size = (
     1  // "ast"
     + (size_t)(east.err.msg != NULL)  // "error"

test/helpers.lua

@@ -271,6 +271,45 @@ local function shallowcopy(orig)
   return copy
 end
 
+local deepcopy
+
+local function id(v)
+  return v
+end
+
+local deepcopy_funcs = {
+  table = function(orig)
+    local copy = {}
+    for k, v in pairs(orig) do
+      copy[deepcopy(k)] = deepcopy(v)
+    end
+  end,
+  number = id,
+  string = id,
+  ['nil'] = id,
+  boolean = id,
+}
+
+deepcopy = function(orig)
+  return deepcopy_funcs[type(orig)](orig)
+end
+
+local REMOVE_THIS = {}
+
+local function mergedicts_copy(d1, d2)
+  local ret = shallowcopy(d1)
+  for k, v in pairs(d2) do
+    if d2[k] == REMOVE_THIS then
+      ret[k] = nil
+    elseif type(d1[k]) == 'table' and type(d2[k]) == 'table' then
+      ret[k] = mergedicts_copy(d1[k], d2[k])
+    else
+      ret[k] = d2[k]
+    end
+  end
+  return ret
+end
+
 local function concat_tables(...)
   local ret = {}
   for i = 1, select('#', ...) do
@@ -413,6 +452,9 @@ return {
   hasenv = hasenv,
   which = which,
   shallowcopy = shallowcopy,
+  deepcopy = deepcopy,
+  mergedicts_copy = mergedicts_copy,
+  REMOVE_THIS = REMOVE_THIS,
   concat_tables = concat_tables,
   dedent = dedent,
   format_luav = format_luav,