From 5b2e6b1ad5977ea41eb5d59b33f6f897530b12fd Mon Sep 17 00:00:00 2001
From: Timothy Brookes <timothy.brookes@spendesk.com>
Date: Wed, 15 Jun 2022 09:51:27 +0100
Subject: [PATCH] fix: rounding inconsistency for negative values in
 math.allocate

---
 src/utils/__tests__/math.test.ts | 3 +++
 src/utils/math.ts                | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/utils/__tests__/math.test.ts b/src/utils/__tests__/math.test.ts
index 6631a59..16809dd 100644
--- a/src/utils/__tests__/math.test.ts
+++ b/src/utils/__tests__/math.test.ts
@@ -117,4 +117,7 @@ describe('allocate()', () => {
   it('returns an array that distributes the provided number to each weight, using the negative weights to increase the amount that can be allocated', () => {
     expect(allocate(100, [-5, 15], 10)).toEqual([-50, 150]);
   });
+  it('returns the same distributions with negative and positive values', () => {
+    expect(allocate(21, [1, 5, 4], 10).map((value) => Math.abs(value))).toEqual(allocate(-21, [1, 5, 4], 10).map((value) => Math.abs(value)))
+  });
 });
diff --git a/src/utils/math.ts b/src/utils/math.ts
index cc2713d..e508411 100644
--- a/src/utils/math.ts
+++ b/src/utils/math.ts
@@ -89,7 +89,7 @@ export function allocate(
   let i = 0;
   while (i < length - 1) {
     const share = (weights[i] / total) * n + crumbs;
-    const wholeShare = Math.floor(share);
+    const wholeShare = Math.trunc(share);
     crumbs = share - wholeShare;
     sum += wholeShare;
     shares[i] = wholeShare;