Fix CLang Tidy error

Author: bblanchon

extras/tests/ResourceManager/StringBuilder.cpp

@@ -6,8 +6,8 @@
 #include <catch.hpp>
 
 #include "Allocators.hpp"
-#include "Literals.hpp"
 
+using namespace ArduinoJson;
 using namespace ArduinoJson::detail;
 
 TEST_CASE("StringBuilder") {
@@ -116,12 +116,12 @@ TEST_CASE("StringBuilder") {
   }
 }
 
-static const char* saveString(StringBuilder& builder, const char* s) {
+static JsonString saveString(StringBuilder& builder, const char* s) {
   VariantData data;
   builder.startString();
   builder.append(s);
   builder.save(&data);
-  return data.asString().c_str();
+  return data.asString();
 }
 
 TEST_CASE("StringBuilder::save() deduplicates strings") {
@@ -134,9 +134,9 @@ TEST_CASE("StringBuilder::save() deduplicates strings") {
     auto s2 = saveString(builder, "world");
     auto s3 = saveString(builder, "hello");
 
-    REQUIRE(s1 == "hello"_s);
-    REQUIRE(s2 == "world"_s);
-    REQUIRE(+s1 == +s3);  // same address
+    REQUIRE(s1 == "hello");
+    REQUIRE(s2 == "world");
+    REQUIRE(+s1.c_str() == +s3.c_str());  // same address
 
     REQUIRE(spy.log() ==
             AllocatorLog{
@@ -152,9 +152,9 @@ TEST_CASE("StringBuilder::save() deduplicates strings") {
     auto s1 = saveString(builder, "hello world");
     auto s2 = saveString(builder, "hello");
 
-    REQUIRE(s1 == "hello world"_s);
-    REQUIRE(s2 == "hello"_s);
-    REQUIRE(+s2 != +s1);  // different address
+    REQUIRE(s1 == "hello world");
+    REQUIRE(s2 == "hello");
+    REQUIRE(+s2.c_str() != +s1.c_str());  // different address
 
     REQUIRE(spy.log() ==
             AllocatorLog{
@@ -169,9 +169,9 @@ TEST_CASE("StringBuilder::save() deduplicates strings") {
     auto s1 = saveString(builder, "hello world");
     auto s2 = saveString(builder, "worl");
 
-    REQUIRE(s1 == "hello world"_s);
-    REQUIRE(s2 == "worl"_s);
-    REQUIRE(s2 != s1);
+    REQUIRE(s1 == "hello world");
+    REQUIRE(s2 == "worl");
+    REQUIRE(s2.c_str() != s1.c_str());  // different address
 
     REQUIRE(spy.log() ==
             AllocatorLog{