Added JsonString::operator!=

extras/tests/Misc/JsonString.cpp

@@ -0,0 +1,60 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2020
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+TEST_CASE("JsonString") {
+  SECTION("Default constructor creates a null JsonString") {
+    JsonString s;
+
+    CHECK(s.isNull() == true);
+    CHECK(s.c_str() == 0);
+    CHECK(s.isStatic() == true);
+  }
+
+  SECTION("Compare null with null") {
+    JsonString a, b;
+
+    CHECK(a == b);
+    CHECK_FALSE(a != b);
+  }
+
+  SECTION("Compare null with non-null") {
+    JsonString a(0), b("hello");
+
+    CHECK_FALSE(a == b);
+    CHECK(a != b);
+  }
+
+  SECTION("Compare non-null with null") {
+    JsonString a("hello"), b(0);
+
+    CHECK_FALSE(a == b);
+    CHECK(a != b);
+  }
+
+  SECTION("Compare different strings") {
+    JsonString a("hello"), b("world");
+
+    CHECK_FALSE(a == b);
+    CHECK(a != b);
+  }
+
+  SECTION("Compare identical by pointer") {
+    JsonString a("hello"), b("hello");
+
+    CHECK(a == b);
+    CHECK_FALSE(a != b);
+  }
+
+  SECTION("Compare identical by value") {
+    char s1[] = "hello";
+    char s2[] = "hello";
+    JsonString a(s1), b(s2);
+
+    CHECK(a == b);
+    CHECK_FALSE(a != b);
+  }
+}