Refactor PurchaseUnitSanitizer to subtract 0.01 instead of rounding down

Refactor PurchaseUnitSanitizer to use singleton pattern

lib/packages/Pattern/SingletonTrait.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace WooCommerce\PayPalCommerce\Vendor\Pattern;
+
+trait SingletonTrait {
+	/**
+	 * The single instance of the class.
+	 *
+	 * @var self
+	 */
+	protected static $instance = null;
+
+	/**
+	 * Static method to get the instance of the Singleton class
+	 *
+	 * @return self|null
+	 */
+	public static function get_instance(): ?self {
+		return self::$instance;
+	}
+
+	/**
+	 * Static method to get the instance of the Singleton class
+	 *
+	 * @param self $instance
+	 * @return self
+	 */
+	protected static function set_instance( self $instance ): self {
+		self::$instance = $instance;
+		return self::$instance;
+	}
+
+}

modules/ppcp-api-client/services.php

@@ -824,11 +824,14 @@ return array(
 		return new OrderTransient( $cache, $purchase_unit_sanitizer );
 	},
 	'api.helper.purchase-unit-sanitizer'        => static function( ContainerInterface $container ): PurchaseUnitSanitizer {
+		if ( $instance = PurchaseUnitSanitizer::get_instance() ) {
+			return $instance;
+		}
 		$settings  = $container->get( 'wcgateway.settings' );
 		assert( $settings instanceof Settings );
 
 		$behavior  = $settings->has( 'subtotal_mismatch_behavior' ) ? $settings->get( 'subtotal_mismatch_behavior' ) : null;
 		$line_name = $settings->has( 'subtotal_mismatch_line_name' ) ? $settings->get( 'subtotal_mismatch_line_name' ) : null;
-		return new PurchaseUnitSanitizer( $behavior, $line_name );
+		return PurchaseUnitSanitizer::singleton( $behavior, $line_name );
 	},
 );

modules/ppcp-api-client/src/Entity/Item.php

@@ -201,13 +201,12 @@ class Item {
 	/**
 	 * Returns the object as array.
 	 *
-	 * @param bool $round_to_floor If value rounding should be floor.
 	 * @return array
 	 */
-	public function to_array( bool $round_to_floor = false ): array {
+	public function to_array(): array {
 		$item = array(
 			'name'        => $this->name(),
-			'unit_amount' => $this->unit_amount()->to_array( $round_to_floor ),
+			'unit_amount' => $this->unit_amount()->to_array(),
 			'quantity'    => $this->quantity(),
 			'description' => $this->description(),
 			'sku'         => $this->sku(),

modules/ppcp-api-client/src/Entity/Money.php

@@ -62,11 +62,10 @@ class Money {
 	/**
 	 * The value formatted as string for API requests.
 	 *
-	 * @param bool $round_to_floor If value rounding should be floor.
 	 * @return string
 	 */
-	public function value_str( bool $round_to_floor = false ): string {
-		return $this->money_formatter->format( $this->value, $this->currency_code, $round_to_floor );
+	public function value_str(): string {
+		return $this->money_formatter->format( $this->value, $this->currency_code );
 	}
 
 	/**
@@ -81,22 +80,12 @@ class Money {
 	/**
 	 * Returns the object as array.
 	 *
-	 * @param bool $round_to_floor If value rounding should be floor.
 	 * @return array
 	 */
-	public function to_array( bool $round_to_floor = false ): array {
+	public function to_array(): array {
 		return array(
 			'currency_code' => $this->currency_code(),
-			'value'         => $this->value_str( $round_to_floor ),
+			'value'         => $this->value_str(),
 		);
 	}
-
-	/**
-	 * Indicates if the default rounding for this value is rounding up.
-	 *
-	 * @return bool
-	 */
-	public function is_rounding_up(): bool {
-		return (float) $this->value_str() > $this->value;
-	}
 }

modules/ppcp-api-client/src/Entity/PurchaseUnit.php

@@ -336,7 +336,7 @@ class PurchaseUnit {
 		}
 
 		if ( $sanitize_output && isset( $this->sanitizer ) ) {
-			$purchase_unit = ( $this->sanitizer->sanitize( $purchase_unit, $this->items(), $allow_ditch_items ) );
+			$purchase_unit = ( $this->sanitizer->sanitize( $purchase_unit, $allow_ditch_items ) );
 		}
 
 		return $purchase_unit;

modules/ppcp-api-client/src/Helper/MoneyFormatter.php

@@ -25,31 +25,12 @@ class MoneyFormatter {
 	 *
 	 * @param float  $value The value.
 	 * @param string $currency The 3-letter currency code.
-	 * @param bool   $round_to_floor If value rounding should be floor.
 	 *
 	 * @return string
 	 */
-	public function format( float $value, string $currency, bool $round_to_floor = false ): string {
-		if ( $round_to_floor ) {
-			return in_array( $currency, $this->currencies_without_decimals, true )
-				? (string) floor( $value )
-				: number_format( $this->floor_with_decimals( $value, 2 ), 2, '.', '' );
-		}
-
+	public function format( float $value, string $currency ): string {
 		return in_array( $currency, $this->currencies_without_decimals, true )
 			? (string) round( $value, 0 )
 			: number_format( $value, 2, '.', '' );
 	}
-
-	/**
-	 * Rounds to floor with decimal precision.
-	 *
-	 * @param float $value The value.
-	 * @param int   $decimals The number of decimals.
-	 * @return float
-	 */
-	private function floor_with_decimals( float $value, int $decimals = 0 ): float {
-		$adjustment = (float) pow( 10, $decimals );
-		return floor( $value * $adjustment ) / $adjustment;
-	}
 }

modules/ppcp-api-client/src/Helper/PurchaseUnitSanitizer.php

@@ -19,11 +19,14 @@ namespace WooCommerce\PayPalCommerce\ApiClient\Helper;
 
 use WooCommerce\PayPalCommerce\ApiClient\Entity\Item;
 use WooCommerce\PayPalCommerce\ApiClient\Entity\Money;
+use WooCommerce\PayPalCommerce\Vendor\Pattern\SingletonTrait;
 
 /**
  * Class PurchaseUnitSanitizer
  */
 class PurchaseUnitSanitizer {
+	use SingletonTrait;
+
 	const MODE_DITCH      = 'ditch';
 	const MODE_EXTRA_LINE = 'extra_line';
 	const VALID_MODES     = array(
@@ -40,13 +43,6 @@ class PurchaseUnitSanitizer {
 	 */
 	private $purchase_unit = array();
 
-	/**
-	 * The purchase unit Item objects
-	 *
-	 * @var array|Item[]
-	 */
-	private $item_objects = array();
-
 	/**
 	 * Whether to allow items to be ditched.
 	 *
@@ -95,6 +91,17 @@ class PurchaseUnitSanitizer {
 		$this->extra_line_name = $extra_line_name;
 	}
 
+	/**
+	 * PurchaseUnitSanitizer singleton.
+	 *
+	 * @param string|null $mode The mismatch handling mode, ditch or extra_line.
+	 * @param string|null $extra_line_name The name of the extra line.
+	 * @return self
+	 */
+	public static function singleton( string $mode = null, string $extra_line_name = null ): self {
+		return self::set_instance( new self( $mode, $extra_line_name ) );
+	}
+
 	/**
 	 * Indicates if mode is ditch.
 	 *
@@ -166,13 +173,11 @@ class PurchaseUnitSanitizer {
 	 * The sanitizes the purchase_unit array.
 	 *
 	 * @param array        $purchase_unit The purchase_unit array that should be sanitized.
-	 * @param array|Item[] $item_objects The purchase unit Item objects used for recalculations.
 	 * @param bool         $allow_ditch_items Whether to allow items to be ditched.
 	 * @return array
 	 */
-	public function sanitize( array $purchase_unit, array $item_objects, bool $allow_ditch_items = true ): array {
+	public function sanitize( array $purchase_unit, bool $allow_ditch_items = true ): array {
 		$this->purchase_unit     = $purchase_unit;
-		$this->item_objects      = $item_objects;
 		$this->allow_ditch_items = $allow_ditch_items;
 
 		$this->sanitize_item_amount_mismatch();
@@ -193,10 +198,9 @@ class PurchaseUnitSanitizer {
 			if ( $item_mismatch < 0 ) {
 
 				// Do floors on item amounts so item_mismatch is a positive value.
-				foreach ( $this->item_objects as $index => $item ) {
-					$this->purchase_unit['items'][ $index ] = $item->to_array(
-						$item->unit_amount()->is_rounding_up()
-					);
+				foreach ( $this->purchase_unit['items'] as $index => $item ) {
+					// get a more intelligent adjustment mechanism
+					$this->purchase_unit['items'][ $index ]['unit_amount']['value'] = ( (float) $this->purchase_unit['items'][ $index ]['unit_amount']['value'] ) - 0.01;
 				}
 			}
 

tests/PHPUnit/ApiClient/Entity/PurchaseUnitTest.php

@@ -662,11 +662,11 @@ class PurchaseUnitTest extends TestCase
 					'insurance' => null,
 				],
 			],
-			'with_rounding_down_only_first_item' => [
-				'message' => 'Extra line should be added with price 0.01 and lines amount 10.00 and 5.00.',
+			'with_two_rounding_down' => [
+				'message' => 'Extra line should be added with price 0.03 and lines amount 10.00 and 4.99.',
 				'expected' => [
-					'item_value' => [10.00, 5.00],
-					'extra_line_value' => 0.01
+					'item_value' => [10.00, 4.99],
+					'extra_line_value' => 0.03
 				],
 				'items' => [
 					[
@@ -693,11 +693,11 @@ class PurchaseUnitTest extends TestCase
 					'insurance' => null,
 				],
 			],
-			'with_multiple_roundings_down' => [
+			'with_many_roundings_down' => [
 				'message' => 'Extra line should be added with price 0.01 and lines amount 10.00, 5.00 and 6.66.',
 				'expected' => [
-					'item_value' => [10.00, 5.00, 6.66],
-					'extra_line_value' => 0.01
+					'item_value' => [10.00, 4.99, 6.66],
+					'extra_line_value' => 0.02
 				],
 				'items' => [
 					[