isArray() deprecation

[thiagopos]

Hi! 👋

Firstly, thanks for your work on this project! 🙂

Today I used patch-package to patch connect-flash@0.1.1 for the project I'm working on.

Here is the diff that solved my problem:

diff --git a/node_modules/connect-flash/lib/flash.js b/node_modules/connect-flash/lib/flash.js
index a278bc1..570c327 100644
--- a/node_modules/connect-flash/lib/flash.js
+++ b/node_modules/connect-flash/lib/flash.js
@@ -64,7 +64,7 @@ function _flash(type, msg) {
     if (arguments.length > 2 && format) {
       var args = Array.prototype.slice.call(arguments, 1);
       msg = format.apply(undefined, args);
-    } else if (isArray(msg)) {
+    } else if (Array.isArray(msg)) {
       msg.forEach(function(val){
         (msgs[type] = msgs[type] || []).push(val);
       });

This issue body was partially generated by patch-package.

[ZaisProjects]

OR Do this: in node_modules/connect-flash/lib/flash.js

Replace it: --> var isArray = require('util').isArray;
with --> var isArray = Array.isArray;

[fgirolami29]

🚨 [IMPORTANT NOTICE – Replacement Maintained]

Hey 👋 Just a heads-up for anyone still waiting for updates on connect-flash:

📦 We’ve created a fully compatible, modern, actively maintained fork:
→ @codecorn/connect-flash-new

✅ Supports:

• CommonJS, ESM, and TypeScript
• Safe session management
• Preview middleware for res.locals.sessionFlash
• Future-ready features and security patches

🛠 Maintained by CodeCorn™
📫 Contact: f.girolami@codecorn.it

"We break things beautifully — then we automate the fix."

Feel free to migrate or open issues/PRs directly there.

[YasharF]

You can also just move off of the dependency with something like:

const { format } = require('util');

const flash = (req, res, next) => {
  if (req.flash) return next();
  req.flash = (type, msg, ...rest) => {
    if (!req.session) throw new Error('req.flash() requires sessions');
    const f = (req.session.flash ||= {});
    if (!type) return (req.session.flash = {}, f);
    if (!msg) return f[type] || [], delete f[type];
    const arr = (f[type] ||= []);
    if (rest.length) arr.push(format(msg, ...rest));
    else if (Array.isArray(msg)) return (arr.push(...msg), arr.length);
    else arr.push(msg);
    return arr;
  };
  res.render = ((r) => function (...a) {
    res.locals.messages = req.flash();
    return r.apply(this, a);
  })(res.render);
  next();
};

app.use(flash);