Examples: Update slippage calculation examples (#27)

Co-authored-by: lgalende <lau@mimic.fi>

Author: ncomerci

examples/09-subgraph-query/src/task.ts

@@ -1,4 +1,4 @@
-import { Address, BigInt, environment, ERC20Token, Swap } from '@mimicprotocol/lib-ts'
+import { Address, BigInt, environment, ERC20Token, Swap, TokenAmount } from '@mimicprotocol/lib-ts'
 import { JSON } from 'json-as/assembly'
 
 import { ERC20 } from './types/ERC20'
@@ -18,11 +18,9 @@ class UniswapPoolsData {
 }
 
 const PRICE_PRECISION: u8 = 40
-const BPS_DENOMINATOR = BigInt.fromI32(10_000)
 
 export default function main(): void {
   if (inputs.tokenIn == inputs.tokenOut) throw new Error('Token in and out must be different')
-  if (BigInt.fromI32(inputs.slippageBps as i32) > BPS_DENOMINATOR) throw new Error('Slippage must be between 0 and 100')
 
   const me = environment.getContext().user
   const amountIn = new ERC20(inputs.tokenIn, inputs.chainId).balanceOf(me).unwrap()
@@ -35,9 +33,9 @@ export default function main(): void {
     .times(price)
     .upscale(tokenOut.decimals)
     .downscale(tokenIn.decimals + PRICE_PRECISION)
-  const slippageFactor = BPS_DENOMINATOR.minus(BigInt.fromI32(inputs.slippageBps as i32))
-  const minAmountOut = expectedOut.times(slippageFactor).div(BPS_DENOMINATOR)
-  Swap.create(inputs.chainId, tokenIn, amountIn, tokenOut, minAmountOut).send()
+  const expectedOutTokenAmount = TokenAmount.fromBigInt(tokenOut, expectedOut)
+  const minAmountOut = expectedOutTokenAmount.applySlippageBps(inputs.slippageBps as i32)
+  Swap.create(inputs.chainId, tokenIn, amountIn, tokenOut, minAmountOut.amount).send()
 }
 
 function getTokenPrice(chainId: i32, subgraphId: string, tokenIn: Address, tokenOut: Address): BigInt {

examples/10-rebalancing-tokens/src/task.ts

@@ -91,15 +91,14 @@ export default function main(): void {
     const tokenInAmount = movedUSD.toTokenAmount(tokensMetadata[surplusTokenIndex]).unwrap()
     const expectedTokenOutAmount = movedUSD.toTokenAmount(tokensMetadata[deficitTokenIndex]).unwrap()
 
-    const slippageFactor = BPS_DENOMINATOR.minus(BigInt.fromI32(inputs.slippageBps as i32))
-    const minAmountOut = expectedTokenOutAmount.amount.times(slippageFactor).div(BPS_DENOMINATOR)
+    const minAmountOut = expectedTokenOutAmount.applySlippageBps(inputs.slippageBps as i32)
 
     Swap.create(
       inputs.chainId,
       tokensMetadata[surplusTokenIndex],
       tokenInAmount.amount,
       tokensMetadata[deficitTokenIndex],
-      minAmountOut
+      minAmountOut.amount
     ).send()
 
     surpluses[surplusIndex].amountUSD = surpluses[surplusIndex].amountUSD.minus(movedUSD)

examples/11-automated-refunds/manifest.yaml

@@ -4,6 +4,6 @@ description: Refunds clients based on past orders
 inputs:
   - chainId: uint32
   - token: string
-  - amount: string       # Amount in wei (as string)
+  - amount: string       # e.g., '1.5' = 1.5 of the given token
   - recipient: address
   - maxFee: string       # e.g., '0.01' = 0.01 of the given token

examples/14-fee-collection/manifest.yaml

@@ -3,6 +3,5 @@ name: Collect Task
 description: Swaps all user tokens for USDC and sends the USDC to a recipient
 inputs:
   - chainId: int32
-  - tokensCsv: string
   - slippageBps: uint16   # e.g., 50 = 0.50%
   - recipient: address

examples/14-fee-collection/src/task.ts

@@ -1,7 +1,6 @@
 import {
   Arbitrum,
   Base,
-  BigInt,
   ChainId,
   environment,
   ListType,
@@ -14,8 +13,6 @@ import {
 
 import { inputs } from './types'
 
-const BPS_DENOMINATOR = BigInt.fromI32(10_000)
-
 export default function main(): void {
   const chainId = inputs.chainId
   const context = environment.getContext()
@@ -28,12 +25,11 @@ export default function main(): void {
   }
 
   const USDC = getUsdc(chainId)
-  const slippageFactor = BPS_DENOMINATOR.minus(BigInt.fromI32(inputs.slippageBps as i32))
 
   for (let i = 0; i < amountsIn.length; i++) {
     const amountIn = amountsIn[i]
     const amountOut = amountIn.toTokenAmount(USDC).unwrap()
-    const minAmountOut = amountOut.times(slippageFactor).div(BPS_DENOMINATOR)
+    const minAmountOut = amountOut.applySlippageBps(inputs.slippageBps as i32)
 
     // Note that the recipient will receive the USDC
     SwapBuilder.forChain(chainId)