From 5ce00c9ddc51b2dda930b6d94ec693032d888072 Mon Sep 17 00:00:00 2001
From: Matthias Kretschmann <m@kretschmann.io>
Date: Tue, 11 Aug 2020 09:30:17 +0200
Subject: [PATCH] use decimal.js for price comparison

---
 package.json                                  |  1 +
 .../organisms/AssetActions/index.tsx          |  6 ++--
 src/utils/compareAsBN.ts                      | 31 ++++++++-----------
 3 files changed, 16 insertions(+), 22 deletions(-)

diff --git a/package.json b/package.json
index 6c4d32360..8faf8f9ba 100644
--- a/package.json
+++ b/package.json
@@ -34,6 +34,7 @@
     "axios": "^0.19.2",
     "classnames": "^2.2.6",
     "date-fns": "^2.15.0",
+    "decimal.js": "^10.2.0",
     "dotenv": "^8.2.0",
     "ethereum-blockies": "github:MyEtherWallet/blockies",
     "filesize": "^6.1.0",
diff --git a/src/components/organisms/AssetActions/index.tsx b/src/components/organisms/AssetActions/index.tsx
index df1293a9f..8f508d521 100644
--- a/src/components/organisms/AssetActions/index.tsx
+++ b/src/components/organisms/AssetActions/index.tsx
@@ -6,7 +6,7 @@ import { MetadataMarket } from '../../../@types/Metadata'
 import { DDO } from '@oceanprotocol/lib'
 import Tabs from '../../atoms/Tabs'
 import { useOcean } from '@oceanprotocol/react'
-import compareAsBN, { Comparison } from '../../../utils/compareAsBN'
+import compareAsBN from '../../../utils/compareAsBN'
 
 export default function AssetActions({
   metadata,
@@ -26,9 +26,7 @@ export default function AssetActions({
     if (!price || !balance || !balance.ocean) return
 
     const isFree = price === '0'
-    setIsBalanceSufficient(
-      isFree ? true : compareAsBN(balance.ocean, price, Comparison.gte)
-    )
+    setIsBalanceSufficient(isFree ? true : compareAsBN(balance.ocean, price))
 
     return () => {
       setIsBalanceSufficient(false)
diff --git a/src/utils/compareAsBN.ts b/src/utils/compareAsBN.ts
index 5f860c0e7..8038773d9 100644
--- a/src/utils/compareAsBN.ts
+++ b/src/utils/compareAsBN.ts
@@ -1,21 +1,16 @@
-import BN from 'bn.js'
+import { Decimal } from 'decimal.js'
 
-export enum Comparison {
-  'lt' = 'lt',
-  'lte' = 'lte',
-  'gt' = 'gt',
-  'gte' = 'gte',
-  'eq' = 'eq'
-}
+// Run decimal.js comparison
+// http://mikemcl.github.io/decimal.js/#cmp
+export default function compareAsBN(balance: string, price: string): boolean {
+  const aBN = new Decimal(balance)
+  const bBN = new Decimal(price)
+  const compare = aBN.comparedTo(bBN)
 
-// Run the corresponding bn.js comparison:
-// https://github.com/indutny/bn.js/#utilities
-export default function compareAsBN(
-  a: string,
-  b: string,
-  comparison: Comparison
-): boolean {
-  const aBN = new BN(a)
-  const bBN = new BN(b)
-  return aBN[comparison](bBN)
+  switch (compare) {
+    case 1 || 0: // balance is greater or equal to price
+      return true
+    default:
+      return false
+  }
 }