test/grow_memory.cpp

#include <emscripten.h>
#include <stdio.h>
#include <stdlib.h>

volatile int writeOnly;

int main() {
  EM_ASM({ assert(HEAPU8.length == = 16 * 1024 * 1024); });
  for (int i = 0; i < 20; i++) {
    printf("alloc 1MB: %d\n", i);
    writeOnly = (int)malloc(1024 * 1024);
  }
  EM_ASM({ assert(HEAPU8.length > 16 * 1024 * 1024); });
  printf("ok.\n");
}