Arduino String.toInt() function wrongly converts to uint32_t - string

Question

I have a webserver running on an ESP32-Wrover_E.
A user's session id is stored in cookie format.
This session ID is coming from esp_random() function which returns an uint32_t type integer. It is being set on log in. When a user goes to any page or reloads it, the http route will check the session ID from the cookie. Sometimes it is matching, other times not.
I have created a wokwi sketch to represent the problem.
toInt() function often times does not convert a String to uint32_t properly.
#include <Arduino.h>
void setup() {
Serial.begin(115200);
String user_session = "2227761735"; // <-- This number comes from esp_random();
uint32_t sessionID = user_session.toInt();
Serial.printf("String session: %s, uint32_t session: %lu\n",user_session,sessionID);
}
void loop() {
vTaskDelay(1);
}
Here is a link to wokwi where you can see it yourself: https://wokwi.com/projects/342242993672028755
Here is the esp_random() function documentation:
https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/system/random.html
How can i convert a String to uint32_t?
EDIT:
If you run this code at wokwi you can see that there are errors in the conversion:
void setup() {
Serial.begin(115200);
String user_session = "2227761735";
uint32_t sessionID = user_session.toInt();
Serial.printf("String session: %s, uint32_t session: %lu\n", user_session, sessionID);
}
boolean isConvertSuccess(uint32_t originalInteger, uint32_t convertedInteger) {
if ( originalInteger == convertedInteger ) {
return true;
}
return false;
}
long lastTestMS = 0;
void testSessionStringToInt() {
if ( millis() - lastTestMS >= 2000 ) {
lastTestMS = millis();
uint32_t newSessionID = esp_random();
Serial.println("\n**********");
Serial.printf("newSessionID: %lu\n", newSessionID);
String sessionComingFromA_Cookie = String(newSessionID);
Serial.printf("sessionComingFromA_Cookie: %s\n", sessionComingFromA_Cookie);
uint32_t convertedIntFromCookieString = sessionComingFromA_Cookie.toInt();
Serial.printf("convertedIntFromCookieString: %lu\n", convertedIntFromCookieString);
Serial.printf(
"Conversion was: %s\n",
isConvertSuccess(newSessionID, convertedIntFromCookieString) ? "success" : "failed"
);
Serial.println("**********");
}
}
void loop() {
delay(10);
testSessionStringToInt();
}

Answer 1

Thanks to #hcheung i just had to convert the uint32_t esp_random() to long and use long everywhere. Here is a link to the corrected wokwi ( where every uint32_t became a long, including the printf("%lu") to printf("%ld") since its not an unsigned ): https://wokwi.com/projects/342242993672028755
And here is the corrected code:
void setup() {
Serial.begin(115200);
String user_session = "2227761735";
long sessionID = (long)user_session.toInt();
Serial.printf("String session: %s, uint32_t session: %ld\n", user_session, sessionID);
}
boolean isConvertSuccess(long originalInteger, long convertedInteger) {
if ( originalInteger == convertedInteger ) {
return true;
}
return false;
}
long lastTestMS = 0;
void testSessionStringToInt() {
if ( millis() - lastTestMS >= 2000 ) {
lastTestMS = millis();
long newSessionID = (long)esp_random();
Serial.println("\n**********");
Serial.printf("newSessionID: %ld\n", newSessionID);
String sessionComingFromA_Cookie = String(newSessionID);
Serial.printf("sessionComingFromA_Cookie: %s\n", sessionComingFromA_Cookie);
long convertedIntFromCookieString = sessionComingFromA_Cookie.toInt();
Serial.printf("convertedIntFromCookieString: %ld\n", convertedIntFromCookieString);
Serial.printf(
"Conversion was: %s\n",
isConvertSuccess(newSessionID, convertedIntFromCookieString) ? "success" : "failed"
);
Serial.println("**********");
}
}
void loop() {
delay(10);
testSessionStringToInt();
}