feat: balance utils with conversion and formatting

src/balance/Balance.chain.ts

@@ -15,6 +15,7 @@ import BN from 'bn.js'
 import { getCached } from '../blockchainApiConnection'
 import Identity from '../identity/Identity'
 import IPublicIdentity from '../types/PublicIdentity'
+import BalanceUtils from './Balance.utils'
 
 /**
  * Fetches the current balance of the account with [accountAddress].
@@ -93,7 +94,8 @@ export async function listenToBalanceChanges(
  *
  * @param identity Identity to use for token transfer.
  * @param accountAddressTo Address of the receiver account.
- * @param amount Amount of Femto-Kilt (1e-15) to transfer.
+ * @param amount Amount of Units to transfer.
+ * @param exponent Magnitude of the amount.
  * @returns Promise containing the transaction status.
  *
  * @example
@@ -117,9 +119,16 @@ export async function listenToBalanceChanges(
 export async function makeTransfer(
   identity: Identity,
   accountAddressTo: IPublicIdentity['address'],
-  amount: BN
+  amount: BN,
+  exponent = -15
 ): Promise<SubmittableResult> {
   const blockchain = await getCached()
-  const transfer = blockchain.api.tx.balances.transfer(accountAddressTo, amount)
+  const transfer = blockchain.api.tx.balances.transfer(
+    accountAddressTo,
+    BalanceUtils.convertToTxUnit(
+      amount,
+      (exponent >= 0 ? 1 : -1) * Math.floor(Math.abs(exponent))
+    )
+  )
   return blockchain.submitTx(identity, transfer)
 }

src/balance/Balance.utils.ts

@@ -0,0 +1,47 @@
+/**
+ * @packageDocumentation
+ * @module BalanceUtils
+ * @preferred
+ */
+
+import BN from 'bn.js'
+import { formatBalance } from '@polkadot/util'
+
+export const KILT_COIN = new BN(1)
+export const KILT_FEMTO_COIN = new BN('1000000000000000')
+
+export const TRANSACTION_FEE = KILT_COIN.divn(1000000000).muln(125)
+
+export const MIN_BALANCE = KILT_COIN.muln(1)
+
+export const ENDOWMENT = KILT_COIN.muln(30)
+
+export function formatKiltBalance(amount: BN): string {
+  return formatBalance(
+    amount,
+    {
+      withSiFull: true,
+      withUnit: 'KILT',
+    },
+    15
+  )
+}
+
+export function asFemtoKilt(balance: BN): BN {
+  return new BN(balance).mul(KILT_FEMTO_COIN)
+}
+
+export function convertToTxUnit(balance: BN, power: number): BN {
+  return new BN(balance).mul(new BN(10).pow(new BN(15 + power)))
+}
+
+export default {
+  KILT_COIN,
+  KILT_FEMTO_COIN,
+  TRANSACTION_FEE,
+  MIN_BALANCE,
+  ENDOWMENT,
+  formatKiltBalance,
+  asFemtoKilt,
+  convertToTxUnit,
+}

src/balance/index.ts

@@ -4,3 +4,4 @@
  */
 
 export * from './Balance.chain'
+export * from './Balance.utils'