[Backport] As low as displays incorrect pricing on category page, tax appears to be added twice #21383

[eduard13]

Original Pull Request

#21395

Description (*)

While calculating minimal price, MinimalTierPriceCalculator is applying tax twice.

magento2/app/code/Magento/Catalog/Pricing/Price/MinimalTierPriceCalculator.php

Lines 35 to 49 in 94383aa

	public function getValue(SaleableInterface $saleableItem)
	{
	/** @var TierPrice $price */
	$price = $saleableItem->getPriceInfo()->getPrice(TierPrice::PRICE_CODE);
	$tierPriceList = $price->getTierPriceList();
	$tierPrices = [];
	foreach ($tierPriceList as $tierPrice) {
	/** @var AmountInterface $price */
	$price = $tierPrice['price'];
	$tierPrices[] = $price->getValue();
	}
	return $tierPrices ? min($tierPrices) : null;
	}

Above function is returning minimum price with tax, and then Magento is applying tax again while returning calculated amount of minimum price

magento2/app/code/Magento/Catalog/Pricing/Price/MinimalTierPriceCalculator.php

Lines 55 to 63 in 94383aa

	public function getAmount(SaleableInterface $saleableItem)
	{
	$value = $this->getValue($saleableItem);
	return $value === null
	? null
	: $this->calculator->getAmount($value, $saleableItem);
	}
	}

Issue can be fixed by excluding 'tax' while calculating return amount.

Fixed Issues (if relevant)

1. As low as displays incorrect pricing on category page, tax appears to be added twice #21383: As low as displays incorrect pricing on category page, tax appears to be added twice

Manual testing scenarios (*)

1. Create tax rules & rates
   1.1 Add 20% tax rate for UK shipping address
2. Create product with tier price and tax class
3. Set Stores->Configuration->Sales->Tax->Price Display Settings->Display Product Prices In Catalog to "Including and Excluding Tax".
4. Create an account and add UK shipping as default address
5. Check category listing page for newly created item
6. Verify As low as price, it should be minimum tier price + tax

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[magento-engcom-team]

Hi @eduard13. Thank you for your contribution
Here is some useful tips how you can test your changes using Magento test environment.
Add the comment under your pull request to deploy test or vanilla Magento instance:

• @magento-engcom-team give me test instance - deploy test instance based on PR changes
• @magento-engcom-team give me 2.2-develop instance - deploy vanilla Magento instance

For more details, please, review the Magento Contributor Assistant documentation

[ghost]

@eduard13 unfortunately, only members of the maintainers team are allowed to assign developers to the pull request

[magento-engcom-team]

Hi @rogyar, thank you for the review.
ENGCOM-4429 has been created to process this Pull Request

[soleksii]

✔️ QA Passed

[ghost]

Hi @eduard13, thank you for your contribution!
Please, complete Contribution Survey, it will take less than a minute.
Your feedback will help us to improve contribution process.

[devchris79]

I have upgraded to 2.3.1 and the issue appears in that version too.