WIP: Fix ipairs() for enum attrs

library/LuaWrapper.cpp

@@ -1534,6 +1534,25 @@ static void FillEnumKeys(lua_State *state, int ix_meta, int ftable, enum_identit
         lua_pushcclosure(state, meta_enum_attr_index, 3);
 
         freeze_table(state, false, (eid->getFullName()+".attrs").c_str());
+        int ix_attrs = lua_gettop(state);
+
+        // add metamethods to metatable of .attrs
+        if (lua_getmetatable(state, ix_attrs))
+        {
+            int ix_attrs_meta = lua_gettop(state);
+
+            if (eid->getFirstItem() <= eid->getLastItem())
+            {
+                lua_pushvalue(state, ix_attrs);
+                lua_pushinteger(state, eid->getFirstItem() - 1);
+                lua_pushinteger(state, eid->getLastItem());
+                lua_pushcclosure(state, wtype_ipairs, 3);
+                lua_setfield(state, ix_attrs_meta, "__ipairs");
+            }
+
+            lua_pop(state, 1); // pop metatable
+        }
+
         lua_setfield(state, ftable, "attrs");
     }
 

test/structures/enum_attrs.lua

@@ -0,0 +1,83 @@
+function test.getmetatable()
+    expect.eq(getmetatable(df.item_type.attrs), 'item_type.attrs')
+end
+
+local function check_valid_attr_entry(enum_type, index)
+    local entry = enum_type.attrs[index]
+    local suffix = ('%s entry at index %s'):format(enum_type._attr_entry_type, index)
+    expect.ne(entry, nil, 'nil ' .. suffix)
+    expect.true_(enum_type._attr_entry_type:is_instance(entry), 'invalid ' .. suffix)
+end
+
+function test.valid_items()
+    for i in ipairs(df.item_type) do
+        check_valid_attr_entry(df.item_type, i)
+    end
+    check_valid_attr_entry(df.item_type, df.item_type._first_item)
+    check_valid_attr_entry(df.item_type, df.item_type._last_item)
+end
+
+function test.valid_items_name()
+    for i, name in ipairs(df.item_type) do
+        expect.eq(df.item_type.attrs[i], df.item_type.attrs[name])
+    end
+end
+
+function test.valid_items_unique()
+    -- check that every enum item has its own attrs entry
+    local addr_to_name = {}
+    for _, name in ipairs(df.item_type) do
+        local _, addr = df.sizeof(df.item_type.attrs[name])
+        if addr_to_name[addr] then
+            expect.fail(('attrs shared between "%s" and "%s"'):format(name, addr_to_name[name]))
+        else
+            addr_to_name[addr] = name
+        end
+    end
+end
+
+function test.invalid_items()
+    check_valid_attr_entry(df.item_type, df.item_type._first_item - 1)
+    check_valid_attr_entry(df.item_type, df.item_type._last_item + 1)
+end
+
+function test.invalid_items_shared()
+    expect.eq(df.item_type.attrs[df.item_type._first_item - 1], df.item_type.attrs[df.item_type._last_item + 1])
+end
+
+function test.length()
+    expect.eq(#df.item_type.attrs, 0)
+end
+
+local function max_attrs_length(enum_type)
+    return enum_type._last_item - enum_type._first_item + 1
+end
+
+function test.pairs()
+    local i = 0
+    for _ in pairs(df.item_type.attrs) do
+        i = i + 1
+        if i > max_attrs_length(df.item_type) then
+            expect.fail('pairs() returned too many items: ' .. tostring(i))
+            break
+        end
+    end
+    expect.eq(i, 0, 'pairs() returned wrong number of items')
+end
+
+function test.ipairs()
+    local i = 0
+    for index, value in ipairs(df.item_type.attrs) do
+        if i == 0 then
+            expect.eq(index, df.item_type._first_item, 'ipairs() returned wrong start index')
+        end
+        i = i + 1
+        if i > max_attrs_length(df.item_type) then
+            expect.fail('ipairs() returned too many items: ' .. tostring(i))
+            break
+        end
+        expect.eq(value, df.item_type.attrs[i + df.item_type._first_item],
+            'ipairs() returned incorrect attrs for item at index: ' .. tostring(index))
+    end
+    expect.eq(i, max_attrs_length(df.item_type), 'ipairs() returned wrong number of items')
+end