Allow using a JsonVariant as a key or index

Closes #2080

extras/tests/JsonVariant/containsKey.cpp

@@ -23,4 +23,12 @@ TEST_CASE("JsonVariant::containsKey()") {
     REQUIRE(var.containsKey(std::string("hello")) == true);
     REQUIRE(var.containsKey(std::string("world")) == false);
   }
+
+  SECTION("containsKey(JsonVariant)") {
+    var["hello"] = "world";
+    var["key"] = "hello";
+
+    REQUIRE(var.containsKey(doc["key"]) == true);
+    REQUIRE(var.containsKey(doc["foo"]) == false);
+  }
 }

extras/tests/JsonVariant/remove.cpp

@@ -81,3 +81,30 @@ TEST_CASE("JsonVariant::remove(std::string)") {
 
   REQUIRE(var.as<std::string>() == "{\"a\":1}");
 }
+
+TEST_CASE("JsonVariant::remove(JsonVariant) from object") {
+  JsonDocument doc;
+  JsonVariant var = doc.to<JsonVariant>();
+
+  var["a"] = "a";
+  var["b"] = 2;
+  var["c"] = "b";
+
+  var.remove(var["c"]);
+
+  REQUIRE(var.as<std::string>() == "{\"a\":\"a\",\"c\":\"b\"}");
+}
+
+TEST_CASE("JsonVariant::remove(JsonVariant) from array") {
+  JsonDocument doc;
+  JsonVariant var = doc.to<JsonVariant>();
+
+  var[0] = 3;
+  var[1] = 2;
+  var[2] = 1;
+
+  var.remove(var[2]);
+  var.remove(var[3]);  // noop
+
+  REQUIRE(var.as<std::string>() == "[3,1]");
+}

extras/tests/JsonVariant/subscript.cpp

@@ -67,6 +67,15 @@ TEST_CASE("JsonVariant::operator[]") {
       REQUIRE(var.is<int>());
       REQUIRE(var.as<int>() == 123);
     }
+
+    SECTION("use JsonVariant as index") {
+      array.add("A");
+      array.add("B");
+      array.add(1);
+
+      REQUIRE(var[var[2]] == "B");
+      REQUIRE(var[var[3]].isNull());
+    }
   }
 
   SECTION("The JsonVariant is a JsonObject") {
@@ -103,6 +112,15 @@ TEST_CASE("JsonVariant::operator[]") {
       JsonArray arr = var["hello"].to<JsonArray>();
       REQUIRE(arr.isNull() == false);
     }
+
+    SECTION("use JsonVariant as key") {
+      object["a"] = "a";
+      object["b"] = "b";
+      object["c"] = "b";
+
+      REQUIRE(var[var["c"]] == "b");
+      REQUIRE(var[var["d"]].isNull());
+    }
   }
 
 #if defined(HAS_VARIABLE_LENGTH_ARRAY) && \