fast_json/Tests/TestJsonHardening.mq5

//+------------------------------------------------------------------+
//|                                            TestJsonHardening.mq5 |
//|                                                       AI-Toolkit |
//+------------------------------------------------------------------+
#property script_show_inputs
#include "../fast_json.mqh"

void OnStart() {
  Print("=== JSON HARDENING & ROBUSTNESS TEST ===");

  //---------------------------------------------------------
  // 1. PRETTY PRINT
  //---------------------------------------------------------
  Print("\n--- 1. Pretty Print Test ---");
  string raw = "{\"a\":1,\"b\":[true,false,null,{\"x\":99.9}]}";
  CJson pp_doc;
  if (pp_doc.Parse(raw)) {
    string pretty = pp_doc.Serialize(true); // true = pretty
    Print("Pretty Output:\n", pretty);
    // Check for newlines
    if (StringFind(pretty, "\n") >= 0 && StringFind(pretty, "   ") >= 0)
      Print("PASS: Pretty Print indentation detected.");
    else
      Print("FAIL: Pretty Print failed.");
  }

  //---------------------------------------------------------
  // 2. ERROR CONTEXT (Line/Col)
  //---------------------------------------------------------
  Print("\n--- 2. Error Context (Line/Col) ---");
  string bad_json = "{\n  \"valid\": 1,\n  \"broken\": UNQUOTED_VALUE\n}";
  CJson bad_doc;
  if (!bad_doc.Parse(bad_json)) {
    int line, col;
    bad_doc.GetErrorPos(line, col);
    Print("Error Code: ", EnumToString((EnumJsonError)bad_doc.GetLastError()));
    Print("Location: Line ", line, ", Col ", col);

    // "broken": starts at line 3. Value starts after.
    // 1: {
    // 2:   "valid": 1,
    // 3:   "broken": UNQUOTED_VALUE
    // The error should be around Line 3, Col ~13

    if (line == 3 && col > 10)
      Print("PASS: Error location accurate.");
    else
      Print("FAIL: Error location mismatch. Expected Line 3.");
  } else {
    Print("FAIL: Should have failed parsing!");
  }

  //---------------------------------------------------------
  // 3. STACK OVERFLOW ATTACK
  //---------------------------------------------------------
  Print("\n--- 3. Stack Exhaustion Attack ---");
  CJsonBuilder bomb_b(65536);

  // Create depth > 512
  int depth = 600;
  string deep = "";
  for (int i = 0; i < depth; i++)
    deep += "[";

  // We manually construct string because Builder might check sp too (which is
  // good) But we want to test PARSER safety.

  Print("Parsing Depth: ", depth);
  CJson bomb_doc;
  // This should return false, NOT CRASH
  // If it crashes, this script stops dead.

  bool res = bomb_doc.Parse(deep);

  if (!res) {
    int err = bomb_doc.GetLastError();
    Print("Parse Result: Error ", EnumToString((EnumJsonError)err));
    if (err == JSON_ERR_STACK_OVERFLOW)
      Print("PASS: Stack Overflow caught gracefully.");
    else
      Print("FAIL: Wrong error code.");
  } else {
    Print("FAIL: Should have failed deep recursion!");
  }

  Print("\n=== SUITE COMPLETE ===");
}