Methods to add certificate scripts for smart staking

[SCMusson]

Following on from #387 and #378, this should add support for staking with staking scripts.

• RedeemerTag.CERT changed to RedemeerTag.CERTIFICATE (see RedeemerTag for certificates is CERT rather than CERTIFICATE #387 and Rename the reward redeemer tag to withdrawal #312)
• TransactionBuilder.add_certificate_script method added
• TransactionBuilder.all_scripts method corrected to include self._certificate_to_redeemers list
• TransactionBuilder._redeemer_list method modified to collect certificate redeemers

[codecov]

Codecov Report

Attention: Patch coverage is 94.73684% with 1 line in your changes missing coverage. Please review.

Project coverage is 85.76%. Comparing base (3034cd9) to head (c95fb61).
Report is 13 commits behind head on main.

Files with missing lines	Patch %	Lines
pycardano/txbuilder.py	94.44%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #388      +/-   ##
==========================================
+ Coverage   85.30%   85.76%   +0.46%     
==========================================
  Files          32       32              
  Lines        4213     4202      -11     
  Branches     1060     1052       -8     
==========================================
+ Hits         3594     3604      +10     
+ Misses        434      421      -13     
+ Partials      185      177       -8     

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[nielstron]

There are some QA issues, make sure to run make qa and fix the remaining errors :)

poetry run flake8 pycardano
pycardano/txbuilder.py:161:1: W293 blank line contains whitespace
pycardano/txbuilder.py:399:121: E501 line too long (131 > 120 characters)
pycardano/txbuilder.py:416:121: E501 line too long (196 > 120 characters)
pycardano/txbuilder.py:519:1: W293 blank line contains whitespace
make: *** [Makefile:64: qa] Error 1

[SCMusson]

Apologies, I should have read the development section more thoroughly.

[nielstron]

No worries, I did the exact same in my first (few) PRs

[nielstron]

We seem to have run into a docker limitation with the CI. @cffls do you know anything about this? Maybe just need to wait a day and retry

[SCMusson]

Coverage should be 100% for the changes made now if someone wants to approve the CI

[nielstron]

Do I understand correctly that the redeemer index is supposed to be directly set by the user according to the order in which they add certificates? (this is the way that it is currently implemented here)

[SCMusson]

Yes, that's how cardano-cli does it. I was thinking that if this causes confusion then the best alternative would be to create an add_certificate method with optional arguments to add a script and redeemer. I assumed that would be a more major change that might be out of scope for this PR.

[nielstron]

Are there script-less certificates?
Either way we can add this upon request

[SCMusson]

The majority of delegation seems to be done with certificates built from stake keys rather than scripts. I think smart staking is relatively niche at the moment.

[nielstron]

Only thing that is missing would be a test that actually submits a transaction that requires spending a SC certificate. Given I neither added this in #308 and no one has complained that it doesn't work I would proceed and approve this.
If @SCMusson you already have a simple reproducible instance of script+transactions that would validate against the spun-up ogmios instance in the CI here, feel free to add it, otherwise I think we can defer it to a follow-up PR.

[SCMusson]

I presume you are referring to the tests in integration-test/test?

[nielstron]

Yes

[SCMusson]

I can't find a way to test withdrawing from a stake script based delegation as you get this error when trying to withdraw 0 ada:

ResponseError: Ogmios responded with error: {'jsonrpc': '2.0', 'method': 'submitTransaction', 'error': {'code': 3141, 'message': "The transaction contains incomplete or invalid rewards withdrawals. When present, rewards withdrawals must consume rewards in full, there cannot be any leftover. The field 'data.incompleteWithdrawals' contains a map of withdrawals and their current rewards balance.", 'data': {'incompleteWithdrawals': {'stake_test17rv0fzzfqdhuzvxtjdx6535l4qx0pwd9n7tp8kyr52gfwpq7eae2v': {'ada': {'lovelace': 0}}}}}, 'id': None}

Obviously there isn't time to allow rewards to accrue during a test.

[nielstron]

Ok. This sounds funny since a major hack of saving memory in recent SC development was using 0 withdrawals - but maybe this refers to another script type.
I'll proceed and merge this, we can check later on how to test it.

[nielstron]

Now you are also not a first-time contributor anymore and new PRs should have the CI run automatically :)