Thousand amount separator

[hynek-jina]

With the use of sat units, there was a need to implement thousand separators for amount in Trezor Suite.
trezor/trezor-suite#5545

The user needs to see the amount in the Suite and on the Trezor device in the same format for control when sending a transaction.

Most required is en-us formatting (like i.e. 123,456.78) but more general solution would be even better for the future.

Acceptance criteria

Given I view my coins in sats
When I prepare a transaction for 4000 sats
And I press Review & Send
Then I should see 'Confirm sending 4,000 sat' on the Trezor

Model 1

Given I see 'Confirm sending 4,000 sat'
When I tap 'Confirm'
Then I should see 'Really send 4,153 sat'

Model T

Given I see 'Confirm sending 4,000 sat'
When I tap 'Confirm'
Then I should see 'Total amount: 4,153 sat'

[sime]

Having a hardcoded locale scheme for a thousand separator when sats are used should be trivial.

We want to avoid locale's that support spaces. Then a single scheme can cover the majority of cases.

@matejcik We would like to avoid spaces for security POV?

[prusnak]

We don't respect locale on Trezor firmware and always use . as a decimal separator. I think we should agree on a thousands separator ( or , or ') and use that statically. Suite should use the same separators as firmware, thus it should not change it according to locale.

[hynek-jina]

Then we can go simply with , thousand separator which is currently in Suite as well.

[bosomt]

QA OK

TT OK

Info:

• Suite version: desktop 22.8.1 (503b472935dec8a9c07aac5eef5ba43f86780a38)
• Browser: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) TrezorSuite/22.8.1 Chrome/100.0.4896.160 Electron/18.3.5 Safari/537.36
• OS: MacIntel
• Screen: 1680x1050
• Device: model T 2.5.2 Universal (revision 0d87b55)
• Device: model 1 1.11.2 Universal (revision 0d87b55)
• Transport: bridge 2.0.31

[bosomt]

Maybe we can consider to adding this separator to Trezor Suite too ?
It would look clearer.

[hynek-jina]

@bosomt
It's almost there: trezor/trezor-suite#5545