chore: Add push_back to the LSP vector types

Author: robertoraggi

packages/cxx-gen-lsp/src/gen_fwd_h.ts

@@ -193,6 +193,18 @@ class Vector<std::variant<Ts...>> final : public LSPObject {
     details::try_emplace(result, repr_->at(index));
     return result;
   }
+
+  template <typename T>
+  [[nodiscard]] auto emplace_back() -> std::variant<Ts...> {
+    std::variant<Ts...> result;
+    details::TryEmplace<T>{}(result, repr_->emplace_back());
+    return result;
+  }
+
+  template <std::derived_from<LSPObject> T>
+  [[nodiscard]] auto emplace_back() -> T {
+    return T(repr_->emplace_back());
+  }
 };
 
 template <typename Key, typename Value>
@@ -272,6 +284,7 @@ export function gen_fwd_h({ model, outputDirectory }: { model: MetaModel; output
   emit(`#pragma once`);
   emit();
   emit(`#include <nlohmann/json.hpp>`);
+  emit(`#include <concepts>`);
   emit(`#include <variant>`);
   emit();
   emit(`namespace cxx::lsp {`);

src/lsp/cxx/lsp/fwd.h

@@ -20,6 +20,7 @@
 
 #pragma once
 
+#include <concepts>
 #include <nlohmann/json.hpp>
 #include <variant>
 
@@ -637,6 +638,18 @@ class Vector<std::variant<Ts...>> final : public LSPObject {
     details::try_emplace(result, repr_->at(index));
     return result;
   }
+
+  template <typename T>
+  [[nodiscard]] auto emplace_back() -> std::variant<Ts...> {
+    std::variant<Ts...> result;
+    details::TryEmplace<T>{}(result, repr_->emplace_back());
+    return result;
+  }
+
+  template <std::derived_from<LSPObject> T>
+  [[nodiscard]] auto emplace_back() -> T {
+    return T(repr_->emplace_back());
+  }
 };
 
 template <typename Key, typename Value>

src/lsp/tests/test_types.cc

@@ -119,3 +119,27 @@ TEST(LSP, StringArrayProperty) {
   ASSERT_EQ(textDocumentContentRegistrationOptions.schemes().at(0), "file");
   ASSERT_EQ(textDocumentContentRegistrationOptions.schemes().at(1), "http");
 }
+
+TEST(LSP, VariantArrayProperty) {
+  auto storage = json::object();
+
+  NotebookDocumentSyncRegistrationOptions
+      notebookDocumentSyncRegistrationOptions{storage};
+
+  auto notebookSelector =
+      notebookDocumentSyncRegistrationOptions.notebookSelector();
+
+  ASSERT_TRUE(notebookSelector.empty());
+
+  auto item = notebookSelector.emplace_back<NotebookDocumentFilterWithCells>();
+
+  ASSERT_FALSE(item.notebook().has_value());
+
+  item.notebook("a_notebook");
+
+  ASSERT_TRUE(item.notebook().has_value());
+
+  ASSERT_EQ(std::get<std::string>(*item.notebook()), "a_notebook");
+
+  ASSERT_EQ(notebookSelector.size(), 1);
+}