Avoid Arduino.h when all its features are disabled (fixes #1692)

CHANGELOG.md

@@ -21,6 +21,8 @@ HEAD
 * Fix inconsistent pool capacity between `BasicJsonDocument`'s copy and move assignments
 * Fix return type of `StaticJsonDocument::operator=`
 * Avoid pool reallocation in `BasicJsonDocument`'s copy assignment if capacity is the same
+* Avoid including `Arduino.h` when all its features are disabled (issue #1692, PR #1693 by @paulocsanz)
+
 
 v6.18.5 (2021-09-28)
 -------

src/ArduinoJson/Configuration.hpp

@@ -116,8 +116,6 @@
 
 #ifdef ARDUINO
 
-#  include <Arduino.h>
-
 // Enable support for Arduino's String class
 #  ifndef ARDUINOJSON_ENABLE_ARDUINO_STRING
 #    define ARDUINOJSON_ENABLE_ARDUINO_STRING 1

src/ArduinoJson/Deserialization/Readers/ArduinoStringReader.hpp

@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <Arduino.h>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 template <typename TSource>

src/ArduinoJson/Deserialization/Readers/FlashReader.hpp

@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <Arduino.h>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 template <>

src/ArduinoJson/Polyfills/pgmspace.hpp

@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <Arduino.h>
+
 #include <ArduinoJson/Configuration.hpp>
 #include <ArduinoJson/Namespace.hpp>
 #include <ArduinoJson/Polyfills/assert.hpp>

src/ArduinoJson/Polyfills/pgmspace_generic.hpp

@@ -5,6 +5,7 @@
 #pragma once
 
 #include <ArduinoJson/Namespace.hpp>
+#include <ArduinoJson/Polyfills/pgmspace.hpp>
 #include <ArduinoJson/Polyfills/type_traits.hpp>
 
 namespace ARDUINOJSON_NAMESPACE {

src/ArduinoJson/Serialization/Writers/PrintWriter.hpp

@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <Arduino.h>
+
 namespace ARDUINOJSON_NAMESPACE {
 
 template <typename TDestination>