esp32 E.openFile stops working after multiple fs.readFile and fs.writeFile

I don’t think I explained myself well enough in my last post above. My apologies.

Every call I make to E.openFile is always followed by an f.close. This works consistently, until a call to E.openFile returns undefined, and i can no longer open and close files, respectively. The above example is explicitly showing the product of this - after running E.openFile, nothing is opened, i.e. undefined is returned (The 3rd-4th lines of the last image demonstrates the execution of the var f, and shows that undefined was assigned to it instead of a file object). Again, I open and close files sequentially, every time I open a file that actually returns a file object, I close right after.

I hope that explains it better. As for the process.memory().free call, I am very grateful you found that work-around! I just hope I can find out why, after opening and closing a file multiple times, and making sure every file I open is indeed closed directly after, eventually causes E.openFile to no longer return anything.

I think the first step in determining why the returned undefined value occurs is to explicitly throw an Out Of Memory error in the C code on the line of code that you’ve provided so it can much more easily be determined that we are simply out of memory vs some other underlying issue:

http://microcosm.app/out/tGLJh

Or, we should make E.openFile configurable in order to enable error throwing when we are out of memory. Again, this will allow developers to choose how to handle and discern whether or not a give api function isn’t working correctly because of lack of memory, or a different bug.

I’d love to hear your thoughts on this, because it wouldn’t cause a lot (if any) of overhead and it gives the developer the choice of how they want to deal with Out Of Memory issues, whether it be via an undefined return value (like it currently does) or an actual thrown error.

Thank you again @Wilberforce!!