Convert Ban's Migrate source tests to new base class

Looks great! Only two nitpicks...

1. +++ b/core/modules/ban/tests/src/Kernel/Plugin/migrate/source/d7/BlockedIpsTest.php
   @@ -0,0 +1,42 @@
   +  protected $expectedResults = [
   +    [
   +      'ip' => '127.0.0.1',
   +    ],
   +  ];
   

   I would rather this was moved directly into providerSource().

2. +++ b/core/modules/ban/tests/src/Kernel/Plugin/migrate/source/d7/BlockedIpsTest.php
   @@ -0,0 +1,42 @@
   +  public function providerSource() {
   +
   +    $databaseContents['blocked_ips'] = [
   

   Nit: Extra blank line here.

Consistency. Part of the purpose of having the new base class is to get rid of warts like $expectedResults, which being a protected property implies that there's only one test pass. (In this case there is, but everything should be in the data provider.)

What? No, it didn't.

See #2807879-14: Convert Contact's Migrate source tests to new base class - let's use better array keys to make it easier to understand what is going on.

Nice. Back to RTBC.

May be I am wrong, but I don't see the comparison between $tests[0]['source_data']['blocked_ips'] and $tests[0]['expected_data'] in 2807845-10.patch.
Could you check please?

I don't see an issue here.
The source & expected data get evaluated by the testSource() method in \Drupal\Tests\migrate\Kernel\MigrateSqlSourceTestBase.
Which provides the given source data to the \Drupal\ban\Plugin\migrate\source\d7\BlockedIps Plugin, which prepares it into the expected data.

Committed and pushed 9baedb6 to 8.3.x and 2f7b4e3 to 8.2.x. Thanks!

Thanks @svendecabooter for the hint.