Changed the array subscript to automatically add missing elements

extras/tests/ElementProxy/set.cpp

@@ -9,7 +9,6 @@ using namespace ARDUINOJSON_NAMESPACE;
 
 TEST_CASE("ElementProxy::set()") {
   DynamicJsonDocument doc(4096);
-  doc.addElement();
   ElementProxy<JsonDocument&> ep = doc[0];
 
   SECTION("set(int)") {

extras/tests/ElementProxy/subscript.cpp

@@ -0,0 +1,25 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2020
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+using namespace ARDUINOJSON_NAMESPACE;
+
+TEST_CASE("MemberProxy::operator[]") {
+  DynamicJsonDocument doc(4096);
+  ElementProxy<JsonDocument&> ep = doc[1];
+
+  SECTION("set member") {
+    ep["world"] = 42;
+
+    REQUIRE(doc.as<std::string>() == "[null,{\"world\":42}]");
+  }
+
+  SECTION("set element") {
+    ep[2] = 42;
+
+    REQUIRE(doc.as<std::string>() == "[null,[null,null,42]]");
+  }
+}

extras/tests/JsonArray/subscript.cpp

@@ -9,7 +9,20 @@
 TEST_CASE("JsonArray::operator[]") {
   DynamicJsonDocument doc(4096);
   JsonArray array = doc.to<JsonArray>();
-  array.add(0);
+
+  SECTION("Pad with null") {
+    array[2] = 2;
+    array[5] = 5;
+    REQUIRE(array.size() == 6);
+    REQUIRE(array[0].isNull() == true);
+    REQUIRE(array[1].isNull() == true);
+    REQUIRE(array[2].isNull() == false);
+    REQUIRE(array[3].isNull() == true);
+    REQUIRE(array[4].isNull() == true);
+    REQUIRE(array[5].isNull() == false);
+    REQUIRE(array[2] == 2);
+    REQUIRE(array[5] == 5);
+  }
 
   SECTION("int") {
     array[0] = 123;

extras/tests/JsonDocument/subscript.cpp

@@ -43,3 +43,11 @@ TEST_CASE("JsonDocument automatically promotes to object") {
 
   REQUIRE(doc["one"]["two"]["three"] == 4);
 }
+
+TEST_CASE("JsonDocument automatically promotes to array") {
+  DynamicJsonDocument doc(4096);
+
+  doc[2] = 2;
+
+  REQUIRE(doc.as<std::string>() == "[null,null,2]");
+}

extras/tests/JsonVariant/subscript.cpp

@@ -43,10 +43,10 @@ TEST_CASE("JsonVariant::operator[]") {
     SECTION("set value") {
       array.add("hello");
 
-      var[0] = "world";
+      var[1] = "world";
 
-      REQUIRE(1 == var.size());
-      REQUIRE(std::string("world") == var[0]);
+      REQUIRE(var.size() == 2);
+      REQUIRE(std::string("world") == var[1]);
     }
 
     SECTION("set value in a nested object") {

extras/tests/MemberProxy/subscript.cpp

@@ -11,9 +11,15 @@ TEST_CASE("MemberProxy::operator[]") {
   DynamicJsonDocument doc(4096);
   MemberProxy<JsonDocument&, const char*> mp = doc["hello"];
 
-  SECTION("set integer") {
+  SECTION("set member") {
     mp["world"] = 42;
 
     REQUIRE(doc.as<std::string>() == "{\"hello\":{\"world\":42}}");
   }
+
+  SECTION("set element") {
+    mp[2] = 42;
+
+    REQUIRE(doc.as<std::string>() == "{\"hello\":[null,null,42]}");
+  }
 }