From 93694c6a65dab0ac431b77bf6caadfea4c0e3c78 Mon Sep 17 00:00:00 2001
From: Tommaso Sciortino <sciortino@gmail.com>
Date: Sat, 27 Sep 2025 05:15:53 -0700
Subject: [PATCH] Make compression algo slightly more aggressive (#10024)

---
 packages/core/src/core/client.test.ts | 4 ++--
 packages/core/src/core/client.ts      | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/core/src/core/client.test.ts b/packages/core/src/core/client.test.ts
index db897a6f2b..6ab25ce658 100644
--- a/packages/core/src/core/client.test.ts
+++ b/packages/core/src/core/client.test.ts
@@ -131,7 +131,7 @@ async function fromAsync<T>(promise: AsyncGenerator<T>): Promise<readonly T[]> {
   return results;
 }
 
-describe('findIndexAfterFraction', () => {
+describe('findCompressSplitPoint', () => {
   it('should throw an error for non-positive numbers', () => {
     expect(() => findCompressSplitPoint([], 0)).toThrow(
       'Fraction must be between 0 and 1',
@@ -156,7 +156,7 @@ describe('findIndexAfterFraction', () => {
       { role: 'model', parts: [{ text: 'This is the fourth message.' }] }, // JSON length: 68 (80%)
       { role: 'user', parts: [{ text: 'This is the fifth message.' }] }, // JSON length: 65 (100%)
     ];
-    expect(findCompressSplitPoint(history, 0.5)).toBe(2);
+    expect(findCompressSplitPoint(history, 0.5)).toBe(4);
   });
 
   it('should handle a fraction of last index', () => {
diff --git a/packages/core/src/core/client.ts b/packages/core/src/core/client.ts
index 5d3015195e..07e645ba9e 100644
--- a/packages/core/src/core/client.ts
+++ b/packages/core/src/core/client.ts
@@ -83,7 +83,6 @@ export function findCompressSplitPoint(
   let lastSplitPoint = 0; // 0 is always valid (compress nothing)
   let cumulativeCharCount = 0;
   for (let i = 0; i < contents.length; i++) {
-    cumulativeCharCount += charCounts[i];
     const content = contents[i];
     if (
       content.role === 'user' &&
@@ -94,6 +93,7 @@ export function findCompressSplitPoint(
       }
       lastSplitPoint = i;
     }
+    cumulativeCharCount += charCounts[i];
   }
 
   // We found no split points after targetCharCount.