Exclude Pay for Order page from logic hiding ECE when taxes may be inaccurate (#3601)

* Exclude Pay for Order page from ECE tax logic

* Add unit test

Author: annemirasol

includes/payment-methods/class-wc-stripe-express-checkout-helper.php

@@ -600,6 +600,7 @@ public function should_show_express_checkout_button() {
 
 		// Hide if cart/product doesn't require shipping and tax is based on billing or shipping address.
 		if (
+			! $this->is_pay_for_order_page() &&
 			(
 				( is_product() && ! $this->product_needs_shipping( $this->get_product() ) ) ||
 				( ( is_cart() || is_checkout() ) && ! WC()->cart->needs_shipping() )

tests/phpunit/test-wc-stripe-express-checkout-helper.php

@@ -60,12 +60,14 @@ public function test_hides_ece_if_cannot_compute_taxes() {
 				'allowed_items_in_cart',
 				'should_show_ece_on_cart_page',
 				'should_show_ece_on_checkout_page',
+				'is_pay_for_order_page',
 			]
 		);
 		$wc_stripe_ece_helper_mock->expects( $this->any() )->method( 'is_product' )->willReturn( false );
 		$wc_stripe_ece_helper_mock->expects( $this->any() )->method( 'allowed_items_in_cart' )->willReturn( true );
 		$wc_stripe_ece_helper_mock->expects( $this->any() )->method( 'should_show_ece_on_cart_page' )->willReturn( true );
 		$wc_stripe_ece_helper_mock->expects( $this->any() )->method( 'should_show_ece_on_checkout_page' )->willReturn( true );
+		$wc_stripe_ece_helper_mock->expects( $this->any() )->method( 'is_pay_for_order_page' )->willReturnOnConsecutiveCalls( true, false );
 		$wc_stripe_ece_helper_mock->testmode = true;
 		if ( ! defined( 'WOOCOMMERCE_CHECKOUT' ) ) {
 			define( 'WOOCOMMERCE_CHECKOUT', true );
@@ -83,6 +85,10 @@ public function test_hides_ece_if_cannot_compute_taxes() {
 		WC()->session->init();
 		WC()->cart->add_to_cart( $virtual_product->get_id(), 1 );
 
+		// Do not hide if Pay for Order page.
+		update_option( 'woocommerce_tax_based_on', 'shipping' );
+		$this->assertTrue( $wc_stripe_ece_helper_mock->should_show_express_checkout_button() );
+
 		// Hide if cart has virtual product and tax is based on shipping or billing address.
 		update_option( 'woocommerce_calc_taxes', 'yes' );
 		update_option( 'woocommerce_tax_based_on', 'billing' );