Context customer object is undefined in getTaxLines

[Xxsource98]

Bug report

Context customer object is undefined in getTaxLines on retrieving.

Describe the bug

I have a custom AbstractTaxService that checks if the customer is a B2B user. If they are, it sets all item rates to 0%; otherwise, it stays with the default rates. I check this using the context argument of the getTaxLines function. The problem arises when I add a product to the cart – it normally returns the values of context.customer object. However, when I try to retrieve my cart, it returns undefined, resetting all taxes to the default rate. I'm unsure if I'm doing something wrong or if it might be a bug.

System information

Medusa version (including plugins): 1.20.0 Node.js version: 20.10.0 Database: Postgres 14 Operating system: Ubuntu 22.04 Browser (if relevant): Brave

Steps to reproduce the behavior

Just retrieve cart with custom AbstractTaxService.

Expected behavior

On retrieving cart it should returns valid context.customer field in getTaxLines function.

Code snippets

async getTaxLines(
    itemLines: ItemTaxCalculationLine[],
    shippingLines: ShippingTaxCalculationLine[],
    context: TaxCalculationContext
  ): Promise<ProviderTaxLine[]> {
    let is_b2b = false

    if (context.customer) {
      is_b2b = context.customer.metadata?.company !== undefined
    }

    console.log('for b2b', is_b2b) // is_b2b only true on adding line item, on retrieving it's always false

    let taxLines: ProviderTaxLine[] = itemLines.flatMap((l) => {
      return l.rates.map((r) => ({
        rate: is_b2b ? 0 : r.rate || 0,
        name: r.name,
        code: is_b2b ? 'zero_tax' : 'default_tax',
        item_id: l.item.id,
      }))
    })

    taxLines = taxLines.concat(
      shippingLines.flatMap((l) => {
        return l.rates.map((r) => ({
          rate: r.rate || 0,
          name: r.name,
          code: r.code,
          shipping_method_id: l.shipping_method.id,
        }))
      })
    )

    return taxLines
  }