Node.js throws a "ENOENT" when I trying to write a file with a name too large

Question

I'm writing a session library for Express.js that stores the sessions in encrypted files. The basic interfaces hierarchy is:

export interface Current<T = any> {
    load(): Promise<T>;
    save(value: T): Promise<void>;
}

export interface Manager {
    current<T = any>(): Current<T>;
    create(): Promise<void>;
    delete(): Promise<void>;
    rewind(): void;
}

declare global {
  namespace Express {
    export interface Request {
      session: Manager;
    }
  }
}

Every session is stored in a JSON file, which name is a unique hash id. That hash is returned to the client as a cookie. The implementation it's like that:

import { sessionCrossover } from '.';
import express from 'express';

const app = express();
app.use(sessionCrossover({
    path: './data',
    expires: 1000 * 10,
    hashLength: 126
}));

For create a new session:

// The data structure of every session in this example
interface Data {
    id: number;
    value: string;
}

// Create an endpoint for create a new session
app.get('/create', async (req, res) => {
    try {
        // Get the current session instance
        const current = req.session.current<Data>();    
        if (!current) {
            // Create a new session instance
            await req.session.create();

            // Save in the current session the data. Just in this
            // case, if the session file doesn't exist, it will
            // be created. This method throws the error...
            await req.session
                .current<Data>()
                .save({
                    id: ++id,
                    value: new Date().toJSON()
                });
    
            res.json('Session created sucessfully');
        } else {
            req.session.rewind();
            res.json('Session rewinded...');
        }
    } catch (err) {
        console.error(err);
        res.json(err);
    }
});

Inside of the method that throws the error:

import { File } from '../tool/fsys';
import { Current } from './interfaces';

export class CurrentSession<T = any> implements Current<T> {
    private _file: File;

    // The related method
    save(value: T): Promise<void> {
        if (!this._killed) {
            const text = JSON.stringify(value, null, '    ');
            const byte = Buffer.from(text, 'utf8');

            // Throws the error
            return this._file.write(byte);
        } else {
            return Promise.resolve();
        }
    }
}

And the File class:

import * as fs from 'fs';
import * as fsPromises from 'fs/promises';

export class File extends FSys {
    // The related method
    public write(byte: Buffer): Promise<void> {
        // this._path it's a  protected property of FSys
        return fsPromises.writeFile(this._path, byte);
    }
}

You can set the current hash length in the middleware shown before. The problem is this:

• When you set a hash of a 126 bytes or more, node.js throws an "ENOENT" error (path not found).
• When the hash is 125 bytes or less the file with the session it's created normally.

My questions are:

• Why node.js thows an "ENOENT" (path not found error) when i try to create a file with a large filename?
• Exists a method to detect a "too large filesize" exception in windows?

Observations:

I tried with different hash byte length. The paths in those cases, are:

• Hash length = 8; OK

C:\Projects\Node.JS\modules\session-crossover\data\be49c866b0181718.json

• Hash length = 64; OK

C:\Projects\Node.JS\modules\session-crossover\data\419410c8db26d74563e31b3c0a12e9fb12d31951abe6b280869af47db088c9acaf251de12cd6b6fc51bf3182fa07597add2b48825498d869b99e914c64d42efa.json

• Hash length = 125; OK

C:\Projects\Node.JS\modules\session-crossover\data\b6f4026e893fb053e626ca3318771a70e0802ca10bfc4ea018e18f35b04aa7f9e365a9883a35eea381d9cb9ad2ca11c8961e0096aacd2802e9e0b4cd96920c073800f40a1224d99a093f7fa0b4eca8799bc84c4fa84db2b8b62df211824271c4d908d3d62defa6f1890e613e04af86bcd04379b57ab3728e0366ed42c9.json

• Hash length = 126; "ENOENT"

C:\Projects\Node.JS\modules\session-crossover\data\7784ae9a697eb7e5a2ccdf7a9b27c4d182e1e637da4efc47d21a1d48f208f1058bf40f6026dccb79702ea61ea3f4ca307fdeb960a38c89187b0c1b66395934a802ee62769810bd191eb85636d6a86c900299b68fcc1ad6ccfbd83aba863fc181a522cd22d0671148b56d6e4c8051b4366439d6855597caad0eb6a4bba043.json