unittests: Free everything and check for memory leaks

Also improves error reporting.

test/unit/helpers.lua

@@ -315,7 +315,7 @@ local function alloc_log_new()
     eq(exp, self.log)
     self:clear()
   end
-  function log:clear_tmp_allocs()
+  function log:clear_tmp_allocs(clear_null_frees)
     local toremove = {}
     local allocs = {}
     for i, v in ipairs(self.log) do
@@ -327,6 +327,8 @@ local function alloc_log_new()
           if v.func == 'free' then
             toremove[#toremove + 1] = i
           end
+        elseif clear_null_frees and v.args[1] == self.null then
+          toremove[#toremove + 1] = i
         end
         if v.func == 'realloc' then
           allocs[tostring(v.ret)] = i
@@ -779,6 +781,12 @@ local function kvi_init(kvi)
   return kvi
 end
 
+local function kvi_destroy(kvi)
+  if kvi.items ~= kvi.init_array then
+    lib.xfree(kvi.items)
+  end
+end
+
 local function kvi_new(ct)
   return kvi_init(ffi.new(ct))
 end
@@ -830,6 +838,7 @@ local module = {
   sc = sc,
   conv_enum = conv_enum,
   array_size = array_sive,
+  kvi_destroy = kvi_destroy,
   kvi_size = kvi_size,
   kvi_init = kvi_init,
   kvi_new = kvi_new,

test/unit/viml/expressions/parser_spec.lua

@@ -5,6 +5,8 @@ local viml_helpers = require('test.unit.viml.helpers')
 
 local make_enum_conv_tab = helpers.make_enum_conv_tab
 local child_call_once = helpers.child_call_once
+local alloc_log_new = helpers.alloc_log_new
+local kvi_destroy = helpers.kvi_destroy
 local conv_enum = helpers.conv_enum
 local ptr2key = helpers.ptr2key
 local cimport = helpers.cimport
@@ -23,6 +25,8 @@ local format_luav = global_helpers.format_luav
 
 local lib = cimport('./src/nvim/viml/parser/expressions.h')
 
+local alloc_log = alloc_log_new()
+
 local function format_check(expr, flags, ast, hls)
   -- That forces specific order.
   print(  format_string('\ncheck_parsing(%r, %u, {', expr, flags))
@@ -230,30 +234,40 @@ end)
 
 describe('Expressions parser', function()
   local function check_parsing(str, flags, exp_ast, exp_highlighting_fs)
-    flags = flags or 0
+    local err, msg = pcall(function()
+      flags = flags or 0
 
-    if os.getenv('NVIM_TEST_PARSER_SPEC_PRINT_TEST_CASE') == '1' then
-      print(str, flags)
-    end
-
-    local pstate = new_pstate({str})
-    local east = lib.viml_pexpr_parse(pstate, flags)
-    local ast = east2lua(pstate, east)
-    local hls = phl2lua(pstate)
-    if exp_ast == nil then
-      format_check(str, flags, ast, hls)
-      return
-    end
-    eq(exp_ast, ast)
-    if exp_highlighting_fs then
-      local exp_highlighting = {}
-      local next_col = 0
-      for i, h in ipairs(exp_highlighting_fs) do
-        exp_highlighting[i], next_col = h(next_col)
+      if os.getenv('NVIM_TEST_PARSER_SPEC_PRINT_TEST_CASE') == '1' then
+        print(str, flags)
       end
-      eq(exp_highlighting, hls)
+      alloc_log:check({})
+
+      local pstate = new_pstate({str})
+      local east = lib.viml_pexpr_parse(pstate, flags)
+      local ast = east2lua(pstate, east)
+      local hls = phl2lua(pstate)
+      if exp_ast == nil then
+        format_check(str, flags, ast, hls)
+        return
+      end
+      eq(exp_ast, ast)
+      if exp_highlighting_fs then
+        local exp_highlighting = {}
+        local next_col = 0
+        for i, h in ipairs(exp_highlighting_fs) do
+          exp_highlighting[i], next_col = h(next_col)
+        end
+        eq(exp_highlighting, hls)
+      end
+      lib.viml_pexpr_free_ast(east)
+      kvi_destroy(pstate.colors)
+      alloc_log:clear_tmp_allocs(true)
+      alloc_log:check({})
+    end)
+    if not err then
+      msg = format_string('Error while processing test (%r, %u):\n%s', str, flags, msg)
+      error(msg)
     end
-    lib.viml_pexpr_free_ast(east)
   end
   local function hl(group, str, shift)
     return function(next_col)