Add remote inbox notifications rule that triggers when WCA is updated (https://github.com/woocommerce/woocommerce-admin/pull/6040)

* Add remote inbox notifications rule that triggers when WCA is updated

* Add changlog entry

* Note that `plugin_version` should be used to check the WCA version

plugins/woocommerce-admin/readme.txt

@@ -97,6 +97,7 @@ Release and roadmap notes are available on the [WooCommerce Developers Blog](htt
 - Add: Add a "rather not say" option to revenue in the profile wizard. #6475
 - Dev: Added warning when WC-Admin is active but not being used #6453
 - Add: Remove Mollie promo note on install #6510
+- Add: Remote Inbox Notifications rule to trigger when WooCommerce Admin is upgraded. #6040
 
 == 2.1.0 ==
 
@@ -172,8 +173,6 @@ Release and roadmap notes are available on the [WooCommerce Developers Blog](htt
 - Add: Allow users to install the PayU plugin in the payments setup task. #6332
 - Fix: Persist the enabling of plugins in the payments setup task. #6332
 
-== Changelog ==
-
 == 1.9.0 1/15/2021 ==
 
 - Fix: Add Customer Type column to the Orders report table. #5820

plugins/woocommerce-admin/src/RemoteInboxNotifications/GetRuleProcessor.php

@@ -56,6 +56,8 @@ class GetRuleProcessor {
 				return new NoteStatusRuleProcessor();
 			case 'option':
 				return new OptionRuleProcessor();
+			case 'wca_updated':
+				return new WooCommerceAdminUpdatedRuleProcessor();
 		}
 
 		return new FailRuleProcessor();

plugins/woocommerce-admin/src/RemoteInboxNotifications/README.md

@@ -425,3 +425,17 @@ This passes when the option value matches the value using the operation.
 ```
 
 `option_name`, `value`, and `operation` are all required. `default` is not required and allows a default value to be used if the option does not exist.
+
+### WCA updated
+This passes when WooCommerce Admin has just been updated. The specs will be run
+on update. Note that this doesn't provide a way to check the version number as
+the `plugin_version` rule can be used to check for a specific version of the
+WooCommerce Admin plugin.
+
+```
+{
+	type: "wca_updated"
+}
+```
+
+No other values are needed.

plugins/woocommerce-admin/src/RemoteInboxNotifications/RemoteInboxNotificationsEngine.php

@@ -19,6 +19,7 @@ use \Automattic\WooCommerce\Admin\Features\Onboarding;
 class RemoteInboxNotificationsEngine {
 	const SPECS_OPTION_NAME        = 'wc_remote_inbox_notifications_specs';
 	const STORED_STATE_OPTION_NAME = 'wc_remote_inbox_notifications_stored_state';
+	const WCA_UPDATED_OPTION_NAME  = 'wc_remote_inbox_notifications_wca_updated';
 
 	/**
 	 * Initialize the engine.
@@ -34,6 +35,10 @@ class RemoteInboxNotificationsEngine {
 			10,
 			2
 		);
+
+		// Hook into WCA updated. This is hooked up here rather than in
+		// on_admin_init because that runs too late to hook into the action.
+		add_action( 'woocommerce_admin_updated', array( __CLASS__, 'run_on_woocommerce_admin_updated' ) );
 	}
 
 	/**
@@ -96,6 +101,19 @@ class RemoteInboxNotificationsEngine {
 		}
 	}
 
+	/**
+	 * Set an option indicating that WooCommerce Admin has just been updated,
+	 * run the specs, then clear that option. This lets the
+	 * WooCommerceAdminUpdatedRuleProcessor trigger on WCA update.
+	 */
+	public static function run_on_woocommerce_admin_updated() {
+		update_option( self::WCA_UPDATED_OPTION_NAME, true );
+
+		self::run();
+
+		update_option( self::WCA_UPDATED_OPTION_NAME, false );
+	}
+
 	/**
 	 * Gets the stored state option, and does the initial set up if it doesn't
 	 * already exist.

plugins/woocommerce-admin/src/RemoteInboxNotifications/WooCommerceAdminUpdatedRuleProcessor.php

@@ -0,0 +1,36 @@
+<?php
+/**
+ * Rule processor for sending when WooCommerce Admin has been updated.
+ */
+
+namespace Automattic\WooCommerce\Admin\RemoteInboxNotifications;
+
+defined( 'ABSPATH' ) || exit;
+
+/**
+ * Rule processor for sending when WooCommerce Admin has been updated.
+ */
+class WooCommerceAdminUpdatedRuleProcessor implements RuleProcessorInterface {
+	/**
+	 * Process the rule.
+	 *
+	 * @param object $rule         The specific rule being processed by this rule processor.
+	 * @param object $stored_state Stored state.
+	 *
+	 * @return bool Whether the rule passes or not.
+	 */
+	public function process( $rule, $stored_state ) {
+		return get_option( RemoteInboxNotificationsEngine::WCA_UPDATED_OPTION_NAME, false );
+	}
+
+	/**
+	 * Validates the rule.
+	 *
+	 * @param object $rule The rule to validate.
+	 *
+	 * @return bool Pass/fail.
+	 */
+	public function validate( $rule ) {
+		return true;
+	}
+}