// Copyright 2025 Google LLC

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//      http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include <cstdint>

#include <string>

#include "fuzzer/FuzzedDataProvider.h"

#include "fuzz_common.h"

#include "fuzz_js_format.h"

namespace {

constexpr const char* kSrc = R"JS(

  (function(s){

    const Stream = require('stream');

    const readable = new Stream.Readable({ read() {} });

    readable.push(s);

    readable.push(null);

    // Return a Promise so the host can pump until idle.

    return (async () => { for await (const c of readable) { c.toString(); } })();

  })

)JS";

} // namespace

extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {

  FuzzedDataProvider fdp(data, size);

  const std::string a0 = fdp.ConsumeRemainingBytesAsString();

  fuzz::IsolateScope iso;

  if (!iso.ok()) return 0;

  const std::string js = FormatJs(

      "try { ({0})({1}); } catch (e) {}",

      std::string(kSrc),

      ToSingleQuotedJsLiteral(a0));

  fuzz::RunEnvString(iso.isolate(), js.c_str());

  return 0;

}