Planner tests: Swap action

[grod220]

Write tests for swap action:

web/packages/wasm/crate/src/planner.rs

Lines 264 to 321 in 8bf66ea

	for tpr::Swap {
	value,
	target_asset,
	// The prepaid fee will instead be calculated directly in the rust planner logic.
	//
	// TODO: external consumers of prax may decide to enable manaual fees, and there may be
	// additional checks required to make sure the fees satisfy to the balancing checks
	// for swap claims.
	fee: _,
	claim_address,
	} in request.swaps
	{
	let value: Value = value
	.ok_or_else(|| anyhow!("missing value in swap"))?
	.try_into()?;
	let target_asset = target_asset
	.ok_or_else(|| anyhow!("missing target asset in swap"))?
	.try_into()?;
	let claim_address = claim_address
	.ok_or_else(|| anyhow!("missing claim address in swap"))?
	.try_into()?;
	// This is the prepaid fee for the swap claim. We don't expect much of a drift in gas
	// prices in a few blocks, and the fee tier adjustments should be enough to cover it.
	let estimated_claim_fee = gas_prices.fee(&swap_claim_gas_cost()).apply_tier(fee_tier);
	// Determine the canonical order for the assets being swapped.
	// This will determine whether the input amount is assigned to delta_1 or delta_2.
	let trading_pair = TradingPair::new(value.asset_id, target_asset);
	// If `trading_pair.asset_1` is the input asset, then `delta_1` is the input amount,
	// and `delta_2` is 0.
	//
	// Otherwise, `delta_1` is 0, and `delta_2` is the input amount.
	let (delta_1, delta_2) = if trading_pair.asset_1() == value.asset_id {
	(value.amount, 0u64.into())
	} else {
	(0u64.into(), value.amount)
	};
	// If there is no input, then there is no swap.
	if delta_1 == Amount::zero() && delta_2 == Amount::zero() {
	return Err(anyhow!("No input value for swap").into());
	}
	// Create the `SwapPlaintext` representing the swap to be performed:
	let swap_plaintext = SwapPlaintext::new(
	&mut OsRng,
	trading_pair,
	delta_1,
	delta_2,
	estimated_claim_fee,
	claim_address,
	);
	let swap = SwapPlan::new(&mut OsRng, swap_plaintext);
	actions_list.push(swap);
	}