fix(view): handle view names ending with "." to avoid require("")

[webdevelopersrinu]

Problem

A view name ending in "." (e.g. res.render('index.') or app.render('index.', cb)) makes the View constructor call require(""), throwing TypeError [ERR_INVALID_ARG_VALUE]: The argument 'id' must be a non-empty string. With app.render() this throws past the callback; with res.render() it surfaces as an opaque 500.

Cause

path.extname('index.') returns '.' (truthy), so the default-engine fallback in lib/view.js is skipped, this.ext stays '.', and this.ext.slice(1) is '' — leading to require('').

Fix

Treat a bare '.' extension as no extension, so the normal default-engine path runs and an unresolved view yields the usual Failed to lookup view error via the callback.

Tests

Added a regression test in test/app.render.js. It fails without the fix (with the ERR_INVALID_ARG_VALUE crash) and passes with it. Full suite (1250 tests) and lint pass.

Fixes #7350

[Ziiyodullayevv]

Good fix for view names ending with dot. This prevents potential security issues with require() receiving empty strings. The validation is simple and effective.

[webdevelopersrinu]

Thanks for taking a look and for the feedback, @Ziiyodullayevv

[haoku123]

Hi @webdevelopersrinu — your fix is correct (and received positive feedback), but the PR has been stalled without maintainer review for a while. I picked it up and re-implemented it on current master in #7420 with the same behavior and test. Thanks for the original work!

[haoku123]

Following up on the duplicate (#7420) — I verified this fix against current master: the change applies cleanly, test/app.render.js passes (22 tests), and the full suite is green (1264 passing). The fix behaves as described: app.render('user.') now invokes the callback with the standard Failed to lookup view "user." error instead of throwing ERR_INVALID_ARG_VALUE synchronously.

@krzysdz would it be possible to review/merge this? Happy to help with anything needed (rebase, additional edge cases, etc.).