Deno•3y ago

Read-only FS detection

Hi, I have few deps that by default create cache/log dirs... I can disable it, but the detection itself is unclear.

Is there a better way than

const canWriteToFs = (() => {
  try {
    Deno.mkdirSync("./log", { recursive: true });
    return true;
  }
  catch {
    return false;
  }
})();

const canWriteToFs = (() => {
  try {
    Deno.mkdirSync("./log", { recursive: true });
    return true;
  }
  catch {
    return false;
  }
})();

Deno AI Helper•11/12/23, 6:53 PM

The documentation suggests that your approach is generally correct. However, it's important to note that you should be careful with the error handling. In your current setup, you're catching all errors and assuming they mean the file system is read-only. However, other errors could occur, such as if you don't have the flag, or if the directory already exists.

Here's a more precise way to check if the file system is read-only:

This code will return

false

false

if the error is thrown, indicating that the file system is read-only. If any other error is thrown, it will be rethrown, allowing you to handle it elsewhere in your code.

Remember to run your script with the and flags, as the function requires write permissions.

Helpful Links:
Deno.watchFs | Runtime APIs | Deno
npm: specifiers | Manual | Deno
Deno 1.10 Release Notes
Deno 1.10 Release Notes

DanielduelOP•11/12/23, 7:54 PM

Actually that's smart