Improved coverage of JsonObject

extras/tests/JsonObject/copy.cpp

@@ -94,4 +94,22 @@ TEST_CASE("JsonObject::set()") {
     REQUIRE(success == false);
     REQUIRE(doc3.as<std::string>() == "{\"hello\":null}");
   }
+
+  SECTION("destination is null") {
+    JsonObject null;
+    obj1["hello"] = "world";
+
+    bool success = null.set(obj1);
+
+    REQUIRE(success == false);
+  }
+
+  SECTION("source is null") {
+    JsonObject null;
+    obj1["hello"] = "world";
+
+    bool success = obj1.set(null);
+
+    REQUIRE(success == false);
+  }
 }

extras/tests/JsonObject/equals.cpp

@@ -50,4 +50,18 @@ TEST_CASE("JsonObject::operator==()") {
     REQUIRE(obj1 == obj2);
     REQUIRE(obj1c == obj2c);
   }
+
+  SECTION("should return false when RHS is null") {
+    JsonObject null;
+
+    REQUIRE_FALSE(obj1 == null);
+    REQUIRE_FALSE(obj1c == null);
+  }
+
+  SECTION("should return false when LHS is null") {
+    JsonObject null;
+
+    REQUIRE_FALSE(null == obj2);
+    REQUIRE_FALSE(null == obj2c);
+  }
 }

extras/tests/JsonObject/iterator.cpp

@@ -30,6 +30,11 @@ TEST_CASE("JsonObject::begin()/end()") {
     REQUIRE(obj.end()->key().isNull());
     REQUIRE(obj.end()->value().isNull());
   }
+
+  SECTION("null JsonObject") {
+    JsonObject null;
+    REQUIRE(null.begin() == null.end());
+  }
 }
 
 TEST_CASE("JsonObjectConst::begin()/end()") {
@@ -60,4 +65,9 @@ TEST_CASE("JsonObjectConst::begin()/end()") {
     REQUIRE(cobj.end()->key().isNull());
     REQUIRE(cobj.end()->value().isNull());
   }
+
+  SECTION("null JsonObjectConst") {
+    JsonObjectConst null;
+    REQUIRE(null.begin() == null.end());
+  }
 }

extras/tests/JsonObject/remove.cpp

@@ -69,4 +69,9 @@ TEST_CASE("JsonObject::remove()") {
     REQUIRE("{\"a\":0,\"c\":2}" == result);
   }
 #endif
+
+  SECTION("should work on null object") {
+    JsonObject null;
+    null.remove("key");
+  }
 }