Memory leak when passed any object to render

[koshkarov]

TEST STEPS:

1. Create a new folder
2. Run npm init
3. Run npm install mustache@4.2.0
4. Create file index.js

const mustache = require("mustache");

function sleep(ms) {
  return new Promise((resolve) => {
    setTimeout(resolve, ms);
  });
}

async function run() {
  await sleep(15000);
  for (let i = 0; i < 20; i++) {
    for (let j = 0; j < 15000; j++) {
      // test line
      mustache.render(`MemoryLeakMessage: ${i}:${j}`, null);

      // this allows to interrupt the process and collect garbage
      await sleep(0);
    }
    await sleep(5000);
  }
}

void run();

5. Run code with inspector node --inspect index.js.
6. Open Chrome Inspector chrome://inspect/
7. Click on inspect link
8. Select Memory tab
9. Click on Take heap snapshot icon once a minute.

ACTUAL RESULT:
The memory heap linearly grows.

EXPECTED RESULT:
The memory heap should not grow.

[koshkarov]

The issue was resolved by setting Mustache.templateCache = undefined;. Not sure what kind of caching mechanism is used, But it seems like it is not adequate. AS with this test the memory consumption can easily go over the memory limits of the application.