feat: Fix kandel division by 0. (#76)

* feat: Fix kandel division by 0.

* test: Fix variable name in validateKandelParams function

.changeset/purple-pants-applaud.md

@@ -0,0 +1,5 @@
+---
+"@mangrovedao/mgv": patch
+---
+
+Fix kandel division by 0

src/lib/kandel/params.test.ts

@@ -1,12 +1,17 @@
 import { describe, expect, inject, it } from 'vitest'
+import { getBook } from '~mgv/actions/book.js'
+import { getClient } from '~test/src/client.js'
 import {
   humanPriceToRawPrice,
   rawPriceToHumanPrice,
 } from '../human-readable.js'
 import { priceFromTick, tickFromPrice } from '../tick.js'
-import { getKandelPositionRawParams } from './params.js'
+import { getKandelPositionRawParams, validateKandelParams } from './params.js'
 
 const { wethUSDC } = inject('markets')
+const params = inject('mangrove')
+
+const client = getClient()
 
 describe('kandel params', () => {
   it('kandel position raw params', () => {
@@ -34,4 +39,24 @@ describe('kandel params', () => {
     const endPrice = rawPriceToHumanPrice(priceFromTick(endTick), wethUSDC)
     expect(endPrice).toApproximateEqual(3500)
   })
+
+  it('validateKandelParams', async () => {
+    const book = await getBook(client, params, wethUSDC)
+
+    const _test = validateKandelParams({
+      minPrice: 3100,
+      midPrice: 3000,
+      maxPrice: 3500,
+      pricePoints: 10n,
+      market: wethUSDC,
+      baseAmount: 10n,
+      quoteAmount: 10n,
+      stepSize: 1n,
+      gasreq: 250_000n,
+      factor: 3,
+      asksLocalConfig: book.asksConfig,
+      bidsLocalConfig: book.bidsConfig,
+      marketConfig: book.marketConfig,
+    })
+  })
 })

src/lib/kandel/params.ts

@@ -153,8 +153,8 @@ export function validateKandelParams(
 
   const { nBids, nAsks } = countBidsAndAsks(distribution)
   // asks gives base and bids gives quote
-  const askGives = params.baseAmount / nAsks
-  const bidGives = params.quoteAmount / nBids
+  const askGives = nAsks > 0 ? params.baseAmount / nAsks : 0n
+  const bidGives = nBids > 0 ? params.quoteAmount / nBids : 0n
 
   distribution = changeGives(distribution, bidGives, askGives)