Add progressive throttling of subscriptions from the same IP address [MAILPOET-1128]

tests/unit/Subscription/ThrottlingTest.php

@@ -0,0 +1,60 @@
+<?php
+namespace MailPoet\Test\Subscription;
+
+use Carbon\Carbon;
+use MailPoet\Models\SubscriberIP;
+use MailPoet\Subscription\Throttling;
+use MailPoet\WP\Hooks;
+
+class ThrottlingTest extends \MailPoetTest {
+  function testItProgressivelyThrottlesSubscriptions() {
+    $_SERVER['REMOTE_ADDR'] = '127.0.0.1';
+    expect(Throttling::throttle())->equals(false);
+    expect(Throttling::throttle())->equals(60);
+    for($i = 0; $i < 11; $i++) {
+      $ip = SubscriberIP::create();
+      $ip->ip = '127.0.0.1';
+      $ip->created_at = Carbon::now()->subMinutes($i);
+      $ip->save();
+    }
+    expect(Throttling::throttle())->equals(MINUTE_IN_SECONDS * pow(2, 10));
+  }
+
+  function testItDoesNotThrottleIfDisabledByAHook() {
+    $_SERVER['REMOTE_ADDR'] = '127.0.0.1';
+    Hooks::addFilter('mailpoet_subscription_limit_enabled', '__return_false');
+    expect(Throttling::throttle())->equals(false);
+    expect(Throttling::throttle())->equals(false);
+    Hooks::removeFilter('mailpoet_subscription_limit_enabled', '__return_false');
+    expect(Throttling::throttle())->greaterThan(0);
+  }
+
+  function testItDoesNotThrottleForLoggedInUsers() {
+    $_SERVER['REMOTE_ADDR'] = '127.0.0.1';
+    $wp_users = get_users();
+    wp_set_current_user($wp_users[0]->ID);
+    expect(Throttling::throttle())->equals(false);
+    expect(Throttling::throttle())->equals(false);
+    wp_set_current_user(0);
+    expect(Throttling::throttle())->greaterThan(0);
+  }
+
+  function testItPurgesOldSubscriberIps() {
+    $ip = SubscriberIP::create();
+    $ip->ip = '127.0.0.1';
+    $ip->save();
+
+    $ip2 = SubscriberIP::create();
+    $ip2->ip = '127.0.0.1';
+    $ip2->created_at = Carbon::now()->subDays(1)->subSeconds(1);
+    $ip2->save();
+
+    expect(SubscriberIP::count())->equals(2);
+    Throttling::throttle();
+    expect(SubscriberIP::count())->equals(1);
+  }
+
+  function _after() {
+    SubscriberIP::deleteMany();
+  }
+}