feat: collateral tracking

[joshuajbouw]

In order to support #171 (DefiLlama integration) we need to be able to expose the metrics of collateral standalone, as well as in the snapshot as well. This would then allow external parties to be able to calculate using the correct TVL method. TVL (total deposits (collateral assets + borrow assets) - outstanding loans)

[joshuajbouw]

@peer2f00l few things that I am unsure about:

• Where is the best appropriate place to add to the tracking of collateral deposits in Contract and Snapshot?
• Does inflight matter like it does in the context of borrowed?

[peer2f00l]

Add collateral step is here:

contracts/contract/market/src/impl_helper.rs

Lines 40 to 70 in b167daf

	pub fn execute_collateralize(
	&mut self,
	account_id: AccountId,
	amount: CollateralAssetAmount,
	price_pair: &PricePair,
	) {
	// TODO: This creates a borrow record implicitly. If we
	// require a discrete "sign-up" step, we will need to add
	// checks before this function call.
	//
	// The sign-up step would only be NFT gating or something of
	// that sort, which is just an additional pre condition check.
	// -- https://github.com/Templar-Protocol/contract-mvp/pull/6#discussion_r1923871982
	if self.borrow_position_ref(account_id.clone()).is_none() {
	self.charge_for_storage(
	&account_id,
	self.storage_usage_borrow_position + self.storage_usage_snapshot * 2,
	);
	}
	let mut borrow_position = self.get_or_create_borrow_position_guard(account_id);
	if borrow_position.inner().is_liquidation_locked {
	env::panic_str("Cannot add collateral while liquidation locked");
	}
	let proof = borrow_position.accumulate_interest();
	require!(
	!borrow_position.is_eligible_for_liquidation(price_pair, env::block_timestamp_ms()),
	"Cannot add collateral when eligible for liquidation",
	);
	borrow_position.record_collateral_asset_deposit(proof, amount);
	}

Withdraw collateral step is here:

contracts/contract/market/src/impl_market_external.rs

Lines 119 to 154 in b167daf

	fn withdraw_collateral(&mut self, amount: CollateralAssetAmount) -> Promise {
	let account_id = env::predecessor_account_id();
	let Some(mut borrow_position) = self.borrow_position_guard(account_id.clone()) else {
	env::panic_str("No borrower record. Please deposit collateral first.");
	};
	if borrow_position
	.inner()
	.get_total_borrow_asset_liability()
	.is_zero()
	{
	// No need to retrieve prices, since there is zero liability.
	let proof = borrow_position.accumulate_interest();
	borrow_position.record_collateral_asset_withdrawal(proof, amount);
	drop(borrow_position);
	self.configuration
	.collateral_asset
	.transfer(account_id.clone(), amount)
	.then(
	self_ext!(Self::GAS_WITHDRAW_COLLATERAL_02_FINALIZE)
	.withdraw_collateral_02_finalize(account_id, amount),
	)
	} else {
	drop(borrow_position);
	// They still have liability, so we need to check prices.
	self.configuration
	.price_oracle_configuration
	.retrieve_price_pair()
	.then(
	self_ext!(Self::GAS_WITHDRAW_COLLATERAL_01_CONSUME_PRICE)
	.withdraw_collateral_01_consume_price(account_id, amount),
	)
	}
	}

You should be able to perform just about all of the necessary calculations as-we-go by adding logic in those two places. (And to the snapshot() function, I suppose.)

[peer2f00l]

Please write tests to ensure the correctness of the new field as it appears in snapshots.

[joshuajbouw]

Added tests and encapsulation on snapshot, which is better to use defined functions so that future updaters don't accidentally make mistakes.

[github-actions]

Name	Deployment
Registry	gh-192.templar-in-training.testnet
Default market	default-16824903940.gh-192.templar-in-training.testnet

---

Gas Report

harvest_yield

Iterations	Gas
0	3.5 Tgas
391	11.1 Tgas

Estimated snapshot limit: 14422

apply_interest

Iterations	Gas
0	3.4 Tgas
391	13.2 Tgas

Estimated snapshot limit: 11235

[peer2f00l]

Tweaked some of the tests. In general, I think they should be more precise (checking actual values instead of just "is non-zero after deposit" or "is different from the previous state after X action").

[joshuajbouw]

Tweaked some of the tests. In general, I think they should be more precise (checking actual values instead of just "is non-zero after deposit" or "is different from the previous state after X action").

Do agree, they should've been more tightly bound. It was mostly the interest that was (understandably) inconsistent, but it could yield false positives.

[joshuajbouw]

Added priority high since this is blocking another priority-high #171.