original_price not calculated correctly due to tax bug

[didkan]

Issue:
If config.tax.sourcePriceIncludesTax is set to true it is never honored when calculating prices due to a bug in platform tax code. There are however some specific prerequisites for this bug to show.
The result of this bug is that original_price, original_price_incl_tax etc will be calculated wrong before sent off to VueStorefront.

Prerequisites:

• Multistore setup (config.storeViews.multistore: true)
• config.storeViews.xx.sourcePriceIncludesTax is not set at all
• config.tax.sourcePriceIncludesTax set to true

The bug is here:
https://github.com/DivanteLtd/vue-storefront-api/blob/29d4ce5998724610f6023275e08dbcc37f802caf/src/platform/magento2/tax.js#L41-L46

When config.storeViews.xx.sourcePriceIncludesTax does not exist in a multistore setup the variable sourcePriceInclTax is set to undefined. The problem is that in the referenced code snippet the variable is tested strictly against null which will give a false negative.

Solution:
Use normal equality operator instead of strict equality operator since it will catch both null and undefined values.
eg. (sourcePriceInclTax == null) instead of (sourcePriceInclTax === null)

[simonmaass]

i just realized the same bug!

@pkarw @gibkigonzo This should be flagged as imported and included as hotfix in my opinion! anything related to prices and payment :)

[pkarw]

will be released with 1.12.1