Catch DNS errors to avoid unhandled exceptions

[fluiddot]

What is this PR doing?

Catches potential DNS errors produced in outbound network requests to avoid unhandled exceptions.

What problem is it solving?

Fixes the problem described in #535.

How is the problem addressed?

The PR introduces a try-catch statement to catch errors produced when invoking lookup to resolve the target host address. When this happens, it sends empty binary data as a notification that the connection initiated but soon after, it closes the connection with error code 3000.

Testing Instructions

The original issue references wp-now, so it's recommended to test the changes using a local build of wp-now from the playground-tools repository.

1. In wordpress-playground repository, run nx build php-wasm-node.
2. Check out playground-tools repository.
3. In playground-rools repository, update the @php-wasm/node dependency to point to the local path of the wordpress-playground repository.

Example:

diff --git forkSrcPrefix/package.json forkDstPrefix/package.json
index cc623dc57810509691383fa068cc8f921c957f48..ac84b7f467c2f7d23b9fa8c5f9487cafdb4644e6 100644
--- forkSrcPrefix/package.json
+++ forkDstPrefix/package.json
@@ -32,7 +32,7 @@
 		"@codemirror/state": "6.2.0",
 		"@codemirror/theme-one-dark": "6.1.1",
 		"@codemirror/view": "6.9.3",
-		"@php-wasm/node": "0.6.10",
+		"@php-wasm/node": "file:../wordpress-playground/dist/packages/php-wasm/node",
 		"@php-wasm/progress": "0.6.10",
 		"@php-wasm/universal": "0.6.10",
 		"@php-wasm/web": "0.6.10",

4. Run npm i.
5. Run nx build wp-now.
6. Run node dist/packages/wp-now/cli.js start.
7. Turn off internet connection.
8. Navigate to the site's WP admin (/wp-admin).
9. Observe no errors are logged and that wp-now doesn't crash.
10. Navigate to /wp-admin/plugin-install.php.
11. Observe no errors are logged and that wp-now doesn't crash.
12. Observe that the page shows an error message due to being offline.
13. Navigate to /wp-admin/update-core.php
14. Observe no errors are logged and that wp-now doesn't crash.

Note

It's recommended to disable the network cache in your browser via the DevTools Network tab.

[fluiddot]

Following this comment, @sejas @adamziel it's my first PR on the wordpress-playground repository, so I welcome all feedback and thoughts. Thanks for the help 🙇 !

[adamziel]

This should do the trick, thank you so much for contributing @fluiddot! 🎉 I just initiated a new npm packages release so wp-now could upgrade – cc @sejas

[sejas]

@fluiddot Thanks for the PR! Great job!