fix(utils): big bumber should give numeric value of 0 for small numbers (#13394)

* fix(utils): big bumber should give numeric value of 0 for small numbers

* circular dep

* fix imports

* fix infinite loop

* fix test

* changeset

packages/core/utils/src/totals/big-number.ts

@@ -1,6 +1,7 @@
 import { BigNumberInput, BigNumberRawValue, IBigNumber } from "@medusajs/types"
 import { BigNumber as BigNumberJS } from "bignumber.js"
-import { isBigNumber, isString } from "../common"
+import { isBigNumber } from "../common/is-big-number"
+import { isString } from "../common/is-string"
 
 export class BigNumber implements IBigNumber {
   static DEFAULT_PRECISION = 20
@@ -80,12 +81,19 @@ export class BigNumber implements IBigNumber {
   }
 
   get numeric(): number {
+    let value: number
     let raw = this.raw_ as BigNumberRawValue
     if (raw) {
-      return new BigNumberJS(raw.value).toNumber()
+      value = new BigNumberJS(raw.value).toNumber()
     } else {
-      return this.numeric_
+      value = this.numeric_
     }
+
+    if (Math.abs(value) <= MEDUSA_EPSILON.numeric_) {
+      return 0
+    }
+
+    return value
   }
 
   set numeric(value: BigNumberInput) {
@@ -111,15 +119,21 @@ export class BigNumber implements IBigNumber {
   }
 
   toJSON(): number {
-    return this.bignumber_
+    const value = this.bignumber_
       ? this.bignumber_?.toNumber()
       : this.raw_
       ? new BigNumberJS(this.raw_.value).toNumber()
       : this.numeric_
+
+    if (Math.abs(value) <= MEDUSA_EPSILON.numeric_) {
+      return 0
+    }
+
+    return value
   }
 
   valueOf(): number {
-    return this.numeric_
+    return this.numeric
   }
 
   [Symbol.toPrimitive](hint) {
@@ -127,6 +141,10 @@ export class BigNumber implements IBigNumber {
       return this.raw?.value
     }
 
-    return this.numeric_
+    return this.numeric
   }
 }
+
+export const MEDUSA_EPSILON = new BigNumber(
+  process.env.MEDUSA_EPSILON || "0.0001"
+)

packages/core/utils/src/totals/credit-lines/index.ts

@@ -1,7 +1,7 @@
 import { BigNumberInput } from "@medusajs/types"
 import { isDefined } from "../../common"
-import { BigNumber } from "../big-number"
-import { MathBN, MEDUSA_EPSILON } from "../math"
+import { BigNumber, MEDUSA_EPSILON } from "../big-number"
+import { MathBN } from "../math"
 
 export function calculateCreditLinesTotal({
   creditLines,

packages/core/utils/src/totals/math.ts

@@ -3,10 +3,6 @@ import { BigNumber as BigNumberJS } from "bignumber.js"
 import { isDefined } from "../common"
 import { BigNumber } from "./big-number"
 
-export const MEDUSA_EPSILON = new BigNumber(
-  process.env.MEDUSA_EPSILON || "0.0001"
-)
-
 type BNInput = BigNumberInput | BigNumber
 export class MathBN {
   static convert(num: BNInput, decimalPlaces?: number): BigNumberJS {

packages/core/utils/src/totals/promotion/index.ts

@@ -1,9 +1,7 @@
 import { BigNumberInput } from "@medusajs/types"
-import {
-  ApplicationMethodAllocation,
-  ApplicationMethodType,
-} from "../../promotion"
-import { MathBN, MEDUSA_EPSILON } from "../math"
+import { ApplicationMethodAllocation, ApplicationMethodType, } from "../../promotion"
+import { MathBN } from "../math"
+import { MEDUSA_EPSILON } from "../big-number"
 
 function getPromotionValueForPercentage(promotion, lineItemAmount) {
   return MathBN.mult(MathBN.div(promotion.value, 100), lineItemAmount)