Added StaticJsonDocument::garbageCollect()

CHANGELOG.md

@@ -13,6 +13,7 @@ HEAD
 * Fixed incorrect string comparison on some platforms (issue #1198)
 * Added move-constructor and move-assignment to `BasicJsonDocument`
 * Added `BasicJsonDocument::garbageCollect()` (issue #1195)
+* Added `StaticJsonDocument::garbageCollect()`
 * Changed copy-constructor of `BasicJsonDocument` to preserve the capacity of the source.
 
 > ### BREAKING CHANGES

extras/tests/JsonDocument/StaticJsonDocument.cpp

@@ -209,4 +209,16 @@ TEST_CASE("StaticJsonDocument") {
       REQUIRE_JSON(doc2, "42");
     }
   }
+
+  SECTION("garbageCollect()") {
+    StaticJsonDocument<256> doc;
+    doc[std::string("example")] = std::string("example");
+    doc.remove("example");
+    REQUIRE(doc.memoryUsage() == JSON_OBJECT_SIZE(1) + 16);
+
+    doc.garbageCollect();
+
+    REQUIRE(doc.memoryUsage() == JSON_OBJECT_SIZE(0));
+    REQUIRE_JSON(doc, "{}");
+  }
 }

src/ArduinoJson/Document/BasicJsonDocument.hpp

@@ -120,7 +120,7 @@ class BasicJsonDocument : AllocatorOwner<TAllocator>, public JsonDocument {
 
   bool garbageCollect() {
     // make a temporary clone and move assign
-    BasicJsonDocument<TAllocator> tmp(*this);
+    BasicJsonDocument tmp(*this);
     if (!tmp.capacity())
       return false;
     tmp.set(*this);

src/ArduinoJson/Document/StaticJsonDocument.hpp

@@ -44,6 +44,11 @@ class StaticJsonDocument : public JsonDocument {
     return *this;
   }
 
+  void garbageCollect() {
+    StaticJsonDocument tmp(*this);
+    set(tmp);
+  }
+
  private:
   char _buffer[_capacity];
 };