fix(config_compiler): support creating list in-place by __patch and _…

…_merge

data/test/config_merge_test.yaml

@@ -46,3 +46,11 @@ merge_tree:
   zerg:
     # overwrite existing list
     ground_units: []
+
+create_list_with_inplace_patch:
+  # map node without data key-value (exclude compiler directives) can be converted to list
+  all_ground_units:
+    __patch:
+      - __append: [scv, marine, firebat, vulture, tank]
+      - __append: {__include: starcraft/protoss/ground_units}
+      - __append: {__include: starcraft/zerg/ground_units}

src/rime/config/config_compiler.cc

@@ -97,8 +97,13 @@ static bool AppendToList(an<ConfigItemRef> target, an<ConfigList> list) {
     return false;
   auto existing_list = As<ConfigList>(**target);
   if (!existing_list) {
-    LOG(ERROR) << "trying to append list to other value";
-    return false;
+    if (!(**target)->empty()) {
+      LOG(ERROR) << "trying to append list to incompatible node type";
+      return false;
+    }
+    // convert empty node (usually map with only compiler directives) to list;
+    // refer to test case RimeConfigMergeTest.CreateListWithInplacePatch
+    existing_list = target->AsList();
   }
   if (list->empty())
     return true;

test/config_compiler_test.cc

@@ -251,6 +251,12 @@ class RimeConfigCircularDependencyTest : public RimeConfigCompilerTestBase {
   }
 };
 
+TEST_F(RimeConfigMergeTest, CreateListWithInplacePatch) {
+  const string& prefix = "create_list_with_inplace_patch/";
+  EXPECT_TRUE(config_->IsList(prefix + "all_ground_units"));
+  EXPECT_EQ(16, config_->GetListSize(prefix + "all_ground_units"));
+}
+
 TEST_F(RimeConfigCircularDependencyTest, BestEffortResolution) {
   const string& prefix = "test/";
   EXPECT_TRUE(config_->IsNull(prefix + "__patch"));