Added tests for Flash strings (closes #1070)

test/MixedConfiguration/CMakeLists.txt

@@ -17,6 +17,7 @@ add_executable(MixedConfigurationTests
 	use_double_1.cpp
 	use_long_long_0.cpp
 	use_long_long_1.cpp
+	enable_progmem_1.cpp
 )
 
 target_link_libraries(MixedConfigurationTests catch)

test/MixedConfiguration/enable_progmem_1.cpp

@@ -0,0 +1,53 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2019
+// MIT License
+
+#include "progmem_emulation.hpp"
+
+#define ARDUINOJSON_ENABLE_PROGMEM 1
+#include <ArduinoJson.h>
+
+#include <catch.hpp>
+
+TEST_CASE("Flash strings") {
+  DynamicJsonDocument doc(2048);
+
+  SECTION("deserializeJson()") {
+    DeserializationError err = deserializeJson(doc, F("{'hello':'world'}"));
+
+    REQUIRE(err == DeserializationError::Ok);
+    REQUIRE(doc["hello"] == "world");
+  }
+
+  SECTION("JsonDocument::operator[]") {
+    doc[F("hello")] = F("world");
+
+    REQUIRE(doc["hello"] == "world");
+  }
+
+  SECTION("JsonDocument::add()") {
+    doc.add(F("world"));
+
+    REQUIRE(doc[0] == "world");
+  }
+
+  SECTION("JsonVariant::set()") {
+    JsonVariant var = doc.to<JsonVariant>();
+
+    var.set(F("world"));
+
+    REQUIRE(var == "world");
+  }
+
+  SECTION("MemberProxy::operator==") {
+    doc["hello"] = "world";
+
+    REQUIRE(doc["hello"] == F("world"));
+  }
+
+  SECTION("ElementProxy::operator==") {
+    doc.add("world");
+
+    REQUIRE(doc[0] == F("world"));
+  }
+}

test/MixedConfiguration/progmem_emulation.hpp

@@ -0,0 +1,41 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2019
+// MIT License
+
+#include <stdint.h>  // uint8_t
+#include <string.h>  // strcmp, strlen...
+
+class __FlashStringHelper;
+
+typedef char prog_char;
+typedef void prog_void;
+
+inline const void* convertPtrToFlash(const void* s) {
+  return reinterpret_cast<const char*>(s) + 42;
+}
+
+inline const void* convertFlashToPtr(const void* s) {
+  return reinterpret_cast<const char*>(s) - 42;
+}
+
+#define F(X) reinterpret_cast<const __FlashStringHelper*>(convertPtrToFlash(X))
+
+inline uint8_t pgm_read_byte_near(const void* p) {
+  return *reinterpret_cast<const uint8_t*>(convertFlashToPtr(p));
+}
+
+inline void* memcpy_P(void* a, const prog_void* b, size_t n) {
+  return memcpy(a, convertFlashToPtr(b), n);
+}
+
+inline int strcmp_P(const char* a, const prog_char* b) {
+  return strcmp(a, reinterpret_cast<const char*>(convertFlashToPtr(b)));
+}
+
+inline int strncmp_P(const char* a, const prog_char* b, size_t n) {
+  return strncmp(a, reinterpret_cast<const char*>(convertFlashToPtr(b)), n);
+}
+
+inline size_t strlen_P(const prog_char* s) {
+  return strlen(reinterpret_cast<const char*>(convertFlashToPtr(s)));
+}