--slug= option of wp site delete works wrong for numeric paths

[vanushwashere]

Bug Report

Are you unsure about which repository to post the bug report into?

• Yes, I reviewed the contribution guidelines.
• Yes, more specifically, I reviewed the guidelines on how to write clear bug reports.

Describe the current, buggy behavior

In case when I have subdomains with numeric slugs, wp site delete --slug=4 searches for the site with id=4, not the site with the slug=4 like 4.example.com.

Describe how other contributors can replicate this bug

• create a site with a numeric slug, like 42
• run wp site delete --slug=42
• you'll get the error that site doesn't exist

Describe what you expect as the correct outcome

• create a site with a numeric slug, like 42
• run wp site delete --slug=42
• 42.example.com site is deleted

Let us know what environment you are running this on

OS:     Linux 4.15.0-1044-gcp wp-cli/wp-cli#46-Ubuntu SMP Mon Sep 16 12:52:27 UTC 2019 x86_64
Shell:
PHP binary:     /usr/bin/php7.3
PHP version:    7.3.9-1+ubuntu16.04.1+deb.sury.org+1
php.ini used:   /etc/php/7.3/cli/php.ini
WP-CLI root dir:        phar://wp-cli.phar/vendor/wp-cli/wp-cli
WP-CLI vendor dir:      phar://wp-cli.phar/vendor
WP_CLI phar path:       /home/wplive/web/wp-live
WP-CLI packages dir:
WP-CLI global config:
WP-CLI project config:
WP-CLI version: 2.4.0

Provide additional context/screenshots

[vanushwashere]

I also tried with single and double quotes but got the same behavior

[danielbachhuber]

As it turns out, this is a flaw in the logic of get_blog_details() (or our use of it). If we pass a numeric value through, get_blog_details() thinks it's a blog ID:

https://github.com/WordPress/wordpress-develop/blob/6.4/src/wp-includes/ms-blogs.php#L174-L180

We'll need to update our use of get_blog_details() to accommodate:

entity-command/src/Site_Command.php

Lines 334 to 336 in b5846bf

	if ( isset( $assoc_args['slug'] ) ) {
	$blog = get_blog_details( trim( $assoc_args['slug'], '/' ) );
	} else {

entity-command/src/Site_Command.php

Lines 978 to 985 in b5846bf

	$slug = Utils\get_flag_value( $assoc_args, 'slug', false );
	if ( $slug ) {
	$blog = get_blog_details( trim( $slug, '/' ) );
	if ( ! $blog ) {
	WP_CLI::error( sprintf( 'Could not find site with slug \'%s\'.', $slug ) );
	}
	return [ $blog->blog_id ];

[shawnhooper]

I'll work on a patch & test for this ticket.