Moved ancillary files to extras/ (fixes #1011)

extras/tests/MemoryPool/StringBuilder.cpp

@@ -0,0 +1,41 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2019
+// MIT License
+
+#include <ArduinoJson/Memory/MemoryPool.hpp>
+#include <ArduinoJson/Memory/StringBuilder.hpp>
+#include <catch.hpp>
+
+using namespace ARDUINOJSON_NAMESPACE;
+
+static char buffer[4096];
+
+TEST_CASE("StringBuilder") {
+  SECTION("Works when buffer is big enough") {
+    MemoryPool pool(buffer, addPadding(JSON_STRING_SIZE(6)));
+
+    StringBuilder str(&pool);
+    str.append("hello");
+
+    REQUIRE(str.complete() == std::string("hello"));
+  }
+
+  SECTION("Returns null when too small") {
+    MemoryPool pool(buffer, sizeof(void*));
+
+    StringBuilder str(&pool);
+    str.append("hello world!");
+
+    REQUIRE(str.complete() == 0);
+  }
+
+  SECTION("Increases size of memory pool") {
+    MemoryPool pool(buffer, addPadding(JSON_STRING_SIZE(6)));
+
+    StringBuilder str(&pool);
+    str.append('h');
+    str.complete();
+
+    REQUIRE(JSON_STRING_SIZE(2) == pool.size());
+  }
+}