Add contains_key to managed maps (#230)

CHANGELOG.md

@@ -9,6 +9,8 @@ NEXT-RELEASE Release notes (YYYY-MM-DD)
 * Add ability to use `managed<std::map<std::string, T>>` in type safe queries when comparing a value for a key. e.g.
   `realm.object<MyObject>().where([](auto& o) { return o.my_map["foo_key"] == "some value"; })`
   Supported operators are `==`, `!=`, `>`, `<`, `>=`, `<=` and `contains(const std::string&)`.
+* Add `managed<std::map<std::string, T>>::contains_key` for conveniently checking if a managed map
+  contains a given key. Use this method in the Type Safe Query API instead of `managed<std::map<std::string, T>>::find`.
 
 ### Compatibility
 * Fileformat: Generates files with format v24. Reads and automatically upgrade from fileformat v10.

include/cpprealm/internal/bridge/query.hpp

@@ -239,6 +239,7 @@ namespace realm::internal::bridge {
         query& dictionary_has_value_for_key_greater_than_equals(col_key column_key, const std::string& key, const mixed& value);
         query& dictionary_has_value_for_key_less_than_equals(col_key column_key, const std::string& key, const mixed& value);
         query& dictionary_contains_string_for_key(col_key column_key, const std::string& key, const std::string& value);
+        query& dictionary_contains_key(col_key column_key, const std::string& key);
         subexpr dictionary_link_subexpr(col_key column_key, col_key link_column_key, const std::string& key);
 
         // Expressions

include/cpprealm/managed_dictionary.hpp

@@ -599,6 +599,9 @@ namespace realm {
         }
 
         iterator find(const std::string& key) {
+            if (m_rbool_query) {
+                throw std::runtime_error("`find` is not available in Type Safe Queries, use `contains_key` instead.");
+            }
             // Dictionary's `find` searches for the index of the value and not the key.
             auto d = m_obj->get_dictionary(m_key);
             auto i = d.find_any_key(key);
@@ -627,6 +630,15 @@ namespace realm {
             m_obj->get_dictionary(m_key).erase(key);
         }
 
+        /// Convenience method to be primarily used in type safe queries.
+        rbool contains_key(const std::string& key) {
+            if (m_rbool_query) {
+                return m_rbool_query->dictionary_has_key(m_key, key);
+            } else {
+                return m_obj->get_dictionary(m_key).find_any_key(key) != size_t(-1);
+            }
+        }
+
         notification_token observe(std::function<void(realm::dictionary_collection_change)>&& fn)
         {
             auto o = internal::bridge::object(*m_realm, *m_obj);

include/cpprealm/rbool.hpp

@@ -236,6 +236,11 @@ namespace realm {
             return *this;
         }
 
+        rbool& dictionary_has_key(internal::bridge::col_key column_key, const std::string& key) {
+            q = internal::bridge::query(q.get_table()).dictionary_contains_key(column_key, key);
+            return *this;
+        }
+
         ~rbool() {
             if (is_for_queries)
                 q.~query();

src/cpprealm/internal/bridge/query.cpp

@@ -671,6 +671,15 @@ namespace realm::internal::bridge {
         return *this;
     }
 
+    query& query::dictionary_contains_key(col_key column_key, const std::string& key) {
+#ifdef CPPREALM_HAVE_GENERATED_BRIDGE_TYPES
+        *reinterpret_cast<Query *>(&m_query) = reinterpret_cast<Query *>(&m_query)->get_table()->column<CoreDictionary>(column_key.operator ColKey()).keys().contains(key);
+#else
+        m_query = std::make_shared<Query>(m_query->get_table()->column<CoreDictionary>(column_key.operator ColKey()).keys().contains(key));
+#endif
+        return *this;
+    }
+
     subexpr query::dictionary_link_subexpr(col_key column_key, col_key link_column_key, const std::string& key) {
 #ifdef CPPREALM_HAVE_GENERATED_BRIDGE_TYPES
         auto table = reinterpret_cast<Query *>(&m_query)->get_table()->column<CoreDictionary>(column_key.operator ColKey()).key(key).get_target_table();

tests/db/map_tests.cpp

@@ -207,6 +207,22 @@ TEST_CASE("map", "[map]") {
         CHECK(as_values == std::map<std::string, std::string>({{"a", std::string("baz")}, {"b", std::string("foo")}}));
     }
 
+    SECTION("contains_key") {
+        auto obj = AllTypesObject();
+        obj.map_str_col = {
+                {"a", std::string("baz")},
+                {"b", std::string("foo")}
+        };
+
+        auto realm = db(std::move(config));
+        auto managed_obj = realm.write([&realm, &obj] {
+            return realm.add(std::move(obj));
+        });
+
+        CHECK(managed_obj.map_str_col.contains_key("a"));
+        CHECK_FALSE(managed_obj.map_str_col.contains_key("c"));
+    }
+
     SECTION("object lifetime") {
         managed<AllTypesObjectLink> ptr;
         {

tests/db/query_tests.cpp

@@ -589,6 +589,12 @@ namespace realm {
 
             // Test non existent key
             CHECK(do_query([](realm::managed<AllTypesObject>& o) -> rbool { return o.map_int_col["NA"] == 1; }) == 0);
+
+            // Check key exists in dictionary
+            CHECK(do_query([](realm::managed<AllTypesObject>& o) -> rbool { return o.map_int_col.contains_key("one"); }) == 3);
+            CHECK(do_query([](realm::managed<AllTypesObject>& o) -> rbool { return o.map_int_col.contains_key("three"); }) == 0);
+            CHECK(do_query([](realm::managed<AllTypesObject>& o) -> rbool { return o.map_int_col.contains_key("one"); }) != 0);
+            CHECK(do_query([](realm::managed<AllTypesObject>& o) -> rbool { return o.map_int_col.contains_key("three"); }) != 3);
         }
     }
 }