Add tests

library/LuaTypes.cpp

@@ -1426,19 +1426,16 @@ static void AddFieldInfoTable(lua_State *state, int ftable_idx, struct_identity
             lua_settable(state, -3);
         }
 
+        // freeze_table(state);  // TODO: make pairs() work
         lua_settable(state, ix_fields);
 
         lua_pop(state, 1); // field name
     }
 
+    // lua_pushvalue(state, ix_fields);
+    // freeze_table(state); // TODO: figure out why this creates an __index cycle for nonexistent fields
     lua_pushvalue(state, ix_wrapper);
     lua_setfield(state, ftable_idx, "_fields");
-    lua_pushvalue(state, ix_fieldinfo);
-    lua_setfield(state, ftable_idx, "_fieldsinfo");
-    lua_pushvalue(state, ix_meta);
-    lua_setfield(state, ftable_idx, "_fieldsmeta");
-    lua_pushvalue(state, ix_fielditer);
-    lua_setfield(state, ftable_idx, "_fieldsiter");
 }
 
 void LuaWrapper::IndexStatics(lua_State *state, int meta_idx, int ftable_idx, struct_identity *pstruct)

test/structures/struct_fields.lua

@@ -0,0 +1,54 @@
+config.target = 'core'
+
+local COORD_FIELD_NAMES = {'x', 'y', 'z', 'isValid', 'clear'}
+local COORD_FIELD_EXPECTED_DATA = {
+    x = {type_name='int16_t'},
+    y = {type_name='int16_t'},
+    z = {type_name='int16_t'},
+    isValid = {type_name='function'},
+    clear = {type_name='function'},
+}
+
+local READONLY_MSG = 'Attempt to change a read%-only table.'
+
+function test.access()
+    local fields = df.coord._fields
+    expect.true_(fields)
+    expect.eq(fields, df.coord._fields)
+
+    for name, expected in pairs(COORD_FIELD_EXPECTED_DATA) do
+        expect.true_(fields[name], name)
+        expect.eq(fields[name].name, name, name)
+        expect.eq(fields[name].type_name, expected.type_name, name)
+        expect.eq(type(fields[name].offset), 'number', name)
+    end
+end
+
+function test.order()
+    local i = 0
+    for name in pairs(df.coord._fields) do
+        i = i + 1
+        expect.eq(name, COORD_FIELD_NAMES[i], i)
+    end
+    expect.eq(i, #COORD_FIELD_NAMES)
+end
+
+function test.nonexistent()
+    expect.nil_(df.coord._fields.nonexistent)
+end
+
+function test.readonly()
+    expect.error_match(READONLY_MSG, function()
+        df.coord._fields.x = 'foo'
+    end)
+    expect.error_match(READONLY_MSG, function()
+        df.coord._fields.nonexistent = 'foo'
+    end)
+    -- see TODOs in LuaTypes.cpp
+    -- expect.error_match(READONLY_MSG, function()
+    --     df.coord._fields.x.name = 'foo'
+    -- end)
+
+    expect.eq(df.coord._fields.x.name, 'x')
+    expect.nil_(df.coord._fields.nonexistent)
+end