Prevent orders being placed when no shipping options are available (#46026)

* Prevent orders being placed with invalid shipping options

* Add changelog

* Add shipping_disable_flat_rate fixture function

* Test checking out with no valid shipping methods selected

* Update tests to add a default shipping method

* Update test_checkout_invalid_shipping_method to disable method

* If shipping methods is null, return an array with an empty string inside

* Replace WC session in tests that rely on setting cookies

* Add MockSessionHandler to handle test cases using cookies

* Add docblock comment

* Expect shipping validation to fail if chosen methods are null

* Add shipping method before testing validate_selected_shipping_methods

* Update MockSessionHandler to handle caching

* Show error when test fails

* Default the chosen shipping methods to an empty array if not set

* Split checks for needs_shipping and valid shipping apart

* Remove unnecessary session set and total calculation

* Fix lint errors

* Init session in each test

* Reimplement required methods (those that are private or use cookies)

* Update phpcs ignore comment to be inline

* Prevent error when accessing unset variable in mock cache

* Fix lint error

Author: opr

plugins/woocommerce/tests/php/src/Blocks/StoreApi/Routes/Checkout.php

@@ -334,6 +334,12 @@ public function test_checkout_create_account() {
 		// Save settings to reset them later.
 		$enable_guest_checkout = get_option( 'woocommerce_enable_guest_checkout' );
 		$enable_signup_login   = get_option( 'woocommerce_enable_signup_and_login_from_checkout' );
+		// We need to replace the WC_Session with a mock because this test relies on cookies being set which
+		// is not easy with PHPUnit. This is a simpler approach.
+		$old_session  = WC()->session;
+		WC()->session = new MockSessionHandler();
+		WC()->session->init();
+
 		update_option( 'woocommerce_enable_guest_checkout', 'yes' );
 		update_option( 'woocommerce_enable_signup_and_login_from_checkout', 'yes' );
 
@@ -392,6 +398,8 @@ public function test_checkout_create_account() {
 		WC()->session = $old_session;
 		update_option( 'woocommerce_enable_guest_checkout', $enable_guest_checkout );
 		update_option( 'woocommerce_enable_signup_and_login_from_checkout', $enable_signup_login );
+		// Return WC_Session to original state.
+		WC()->session = $old_session;
 	}
 
 	/**
@@ -407,6 +415,12 @@ public function test_checkout_do_not_create_account() {
 		// Save settings to reset them later.
 		$enable_guest_checkout = get_option( 'woocommerce_enable_guest_checkout' );
 		$enable_signup_login   = get_option( 'woocommerce_enable_signup_and_login_from_checkout' );
+		// We need to replace the WC_Session with a mock because this test relies on cookies being set which
+		// is not easy with PHPUnit. This is a simpler approach.
+		$old_session  = WC()->session;
+		WC()->session = new MockSessionHandler();
+		WC()->session->init();
+
 		update_option( 'woocommerce_enable_guest_checkout', 'yes' );
 		update_option( 'woocommerce_enable_signup_and_login_from_checkout', 'yes' );
 
@@ -462,6 +476,8 @@ public function test_checkout_do_not_create_account() {
 		WC()->session = $old_session;
 		update_option( 'woocommerce_enable_guest_checkout', $enable_guest_checkout );
 		update_option( 'woocommerce_enable_signup_and_login_from_checkout', $enable_signup_login );
+		// Return WC_Session to original state.
+		WC()->session = $old_session;
 	}
 
 	/**
@@ -477,6 +493,12 @@ public function test_checkout_force_create_account() {
 		// Save settings to reset them later.
 		$enable_guest_checkout = get_option( 'woocommerce_enable_guest_checkout' );
 		$enable_signup_login   = get_option( 'woocommerce_enable_signup_and_login_from_checkout' );
+		// We need to replace the WC_Session with a mock because this test relies on cookies being set which
+		// is not easy with PHPUnit. This is a simpler approach.
+		$old_session  = WC()->session;
+		WC()->session = new MockSessionHandler();
+		WC()->session->init();
+
 		update_option( 'woocommerce_enable_guest_checkout', 'no' );
 		update_option( 'woocommerce_enable_signup_and_login_from_checkout', 'yes' );
 
@@ -534,6 +556,8 @@ public function test_checkout_force_create_account() {
 		WC()->session = $old_session;
 		update_option( 'woocommerce_enable_guest_checkout', $enable_guest_checkout );
 		update_option( 'woocommerce_enable_signup_and_login_from_checkout', $enable_signup_login );
+		// Return WC_Session to original state.
+		WC()->session = $old_session;
 	}
 
 	/**