From 74f3390413d47853939df514982fd48faf44cd2c Mon Sep 17 00:00:00 2001
From: "sebastien.arod@gmail.com" <sebastien.arod+framagit@gmail.com>
Date: Tue, 4 Jun 2024 21:26:08 +0200
Subject: [PATCH] fix: generateConsecutivePeriods to end 1 millisecond before
 next period start

---
 src/period/generateConsecutivePeriods.test.ts | 4 ++--
 src/period/generateConsecutivePeriods.ts      | 6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/period/generateConsecutivePeriods.test.ts b/src/period/generateConsecutivePeriods.test.ts
index 66869d1..fa16080 100644
--- a/src/period/generateConsecutivePeriods.test.ts
+++ b/src/period/generateConsecutivePeriods.test.ts
@@ -14,11 +14,11 @@ describe("generateConsecutivePeriods", () => {
 
     expect(results[0]).toEqual({
       start: new Date(Date.UTC(2020, 0, 1)),
-      end: new Date(Date.UTC(2021, 0, 1)),
+      end: new Date(Date.UTC(2020, 11, 31, 23, 59, 59, 999)),
     });
     expect(results[4]).toEqual({
       start: new Date(Date.UTC(2024, 0, 1)),
-      end: new Date(Date.UTC(2025, 0, 1)),
+      end: new Date(Date.UTC(2024, 11, 31, 23, 59, 59, 999)),
     });
   });
 });
diff --git a/src/period/generateConsecutivePeriods.ts b/src/period/generateConsecutivePeriods.ts
index 010749b..1bc9367 100644
--- a/src/period/generateConsecutivePeriods.ts
+++ b/src/period/generateConsecutivePeriods.ts
@@ -1,3 +1,4 @@
+import { addMilliseconds } from "date-fns";
 import { Period } from "./Period";
 
 export default function generateConsecutivePeriods({
@@ -14,7 +15,8 @@ export default function generateConsecutivePeriods({
     let nextPeriodStart = start;
     do {
       const periodStart = nextPeriodStart;
-      const periodEnd = incrementStart(nextPeriodStart);
+      nextPeriodStart = incrementStart(periodStart);
+      const periodEnd = addMilliseconds(nextPeriodStart, -1);
       if (periodEnd.getTime() < periodStart.getTime()) {
         throw new Error("incrementStart call decremented date!!!");
       }
@@ -22,8 +24,6 @@ export default function generateConsecutivePeriods({
         start: periodStart,
         end: periodEnd,
       });
-
-      nextPeriodStart = periodEnd;
     } while (nextPeriodStart.getTime() < end.getTime());
   }
   return periods;