Refactor logic and add comments

Author: Dinamiko

modules/ppcp-api-client/src/Factory/PurchaseUnitFactory.php

@@ -191,12 +191,7 @@ function ( Item $item ): bool {
 		if ( $this->shipping_needed( ...array_values( $items ) ) && $customer instanceof \WC_Customer ) {
 			$shipping         = $this->shipping_factory->from_wc_customer( \WC()->customer, $with_shipping_options );
 			$shipping_address = $shipping->address();
-			if (
-				! $shipping_address ||
-				2 !== strlen( $shipping_address->country_code() ) ||
-				! $shipping_address->admin_area_2() ||
-				( ! $shipping_address->postal_code() && ! $this->country_without_postal_code( $shipping_address->country_code() ) )
-			) {
+			if ( ! $shipping_address || ! $this->can_use_shipping_address( $shipping_address ) ) {
 				$shipping = null;
 			}
 		}
@@ -388,11 +383,51 @@ private function sanitize_soft_descriptor( string $soft_descriptor ): string {
 	 * @return bool
 	 */
 	private function should_disable_shipping( array $items, ?Address $shipping_address ): bool {
-		return ! $this->shipping_needed( ...array_values( $items ) ) ||
-				! $shipping_address ||
-				empty( $shipping_address->country_code() ) ||
-				empty( $shipping_address->address_line_1() ) ||
-				empty( $shipping_address->admin_area_2() ) ||
-				( ! $shipping_address->postal_code() && ! $this->country_without_postal_code( $shipping_address->country_code() ) );
+		// No items require physical shipping.
+		if ( ! $this->shipping_needed( ...array_values( $items ) ) ) {
+			return true;
+		}
+
+		// Cannot proceed without a shipping address.
+		if ( ! $shipping_address ) {
+			return true;
+		}
+
+		return ! $this->can_use_shipping_address( $shipping_address );
+	}
+
+	/**
+	 * Decides whether a shipping address is complete enough to send to PayPal.
+	 *
+	 * PayPal's Orders v2 API rejects incomplete addresses. For virtually every
+	 * country, country_code, address_line_1, admin_area_2 (city), and postal_code
+	 * are required. A small set of countries (see country_without_postal_code())
+	 * have an optional postal code; city is still required there.
+	 *
+	 * @param Address $shipping_address The address to validate.
+	 * @return bool True if the address is usable, false if it should be dropped.
+	 */
+	private function can_use_shipping_address( Address $shipping_address ): bool {
+		// Country code must be a valid 2-letter ISO code.
+		if ( 2 !== strlen( $shipping_address->country_code() ) ) {
+			return false;
+		}
+
+		// Street address is required.
+		if ( empty( $shipping_address->address_line_1() ) ) {
+			return false;
+		}
+
+		// City is required in virtually every country per PayPal's address rules.
+		if ( empty( $shipping_address->admin_area_2() ) ) {
+			return false;
+		}
+
+		// Postal code is required unless the country is on the no-postal-code allowlist.
+		if ( empty( $shipping_address->postal_code() ) && ! $this->country_without_postal_code( $shipping_address->country_code() ) ) {
+			return false;
+		}
+
+		return true;
 	}
 }

tests/PHPUnit/ApiClient/Factory/PurchaseUnitFactoryTest.php

@@ -290,6 +290,33 @@ public function test_wc_cart_shipping_gets_dropped_when_no_country_code()
 		$this->assertNull($unit->shipping());
 	}
 
+	public function test_wc_cart_shipping_gets_dropped_when_no_address_line_1()
+	{
+		$wc_customer = Mockery::mock(\WC_Customer::class);
+		expect('WC')->andReturn((object) ['customer' => $wc_customer, 'session' => null]);
+
+		$wc_cart = Mockery::mock(\WC_Cart::class);
+		$amount = Mockery::mock(Amount::class);
+		$shipping = $this->create_shipping_mock(
+			$this->create_address_mock('DE', '12345', '', 'Berlin')
+		);
+
+		$shipping_factory = Mockery::mock(ShippingFactory::class);
+		$shipping_factory->expects('from_wc_customer')->with($wc_customer, false)->andReturn($shipping);
+
+		$testee = $this->create_testee(
+			$this->create_amount_factory_mock($amount, 'from_wc_cart', $wc_cart),
+			$this->create_item_factory_mock([$this->item], 'from_wc_cart', $wc_cart),
+			$shipping_factory,
+			null,
+			null,
+			$this->create_payment_level_eligibility_mock('', false)
+		);
+
+		$unit = $testee->from_wc_cart($wc_cart);
+		$this->assertNull($unit->shipping());
+	}
+
 	public function test_wc_cart_shipping_gets_dropped_when_no_city()
 	{
 		$wc_customer = Mockery::mock(\WC_Customer::class);