From 0a679226bbb3e0857097b26ed1ac737f4b77bc52 Mon Sep 17 00:00:00 2001
From: Christian Gunderman <gundermanc@google.com>
Date: Wed, 28 Jan 2026 17:15:09 -0800
Subject: [PATCH] Cleanup eval.

---
 evals/read_file_optimization.eval.ts | 95 ++++++----------------------
 1 file changed, 20 insertions(+), 75 deletions(-)

diff --git a/evals/read_file_optimization.eval.ts b/evals/read_file_optimization.eval.ts
index a317b0039b..d00cae3353 100644
--- a/evals/read_file_optimization.eval.ts
+++ b/evals/read_file_optimization.eval.ts
@@ -6,70 +6,9 @@
 
 import { describe, expect } from 'vitest';
 import { evalTest } from './test-helper.js';
-import { GREP_TOOL_NAME, READ_FILE_TOOL_NAME } from '@google/gemini-cli-core';
+import { READ_FILE_TOOL_NAME } from '@google/gemini-cli-core';
 
 describe('optimization_evals', () => {
-  evalTest('ALWAYS_PASSES', {
-    name: 'should avoid reading entire file when fixing scattered linter issues',
-    files: {
-      'linter_mess.ts': (() => {
-        const lines = [];
-        for (let i = 0; i < 4000; i++) {
-          if (i % 300 === 0) {
-            lines.push(`var oldVar${i} = "needs fix";`); // 'var' is the "linter error"
-          } else {
-            lines.push(`const goodVar${i} = "clean";`);
-          }
-        }
-        return lines.join('\n');
-      })(),
-    },
-    prompt:
-      'Start by searching for "var" in linter_mess.ts. Then, using the line numbers from the search results, read only the 5 lines of context around each match to verify safety before fixing.',
-    assert: async (rig, result) => {
-      const logs = rig.readToolLogs();
-
-      // 1. Check if the agent read the whole file
-      const readCalls = logs.filter(
-        (log) => log.toolRequest?.name === READ_FILE_TOOL_NAME,
-      );
-      expect(
-        readCalls.length,
-        'Agent should have used read_file to check context',
-      ).toBeGreaterThan(0);
-
-      for (const call of readCalls) {
-        const args = JSON.parse(call.toolRequest.args);
-        if (args.file_path.includes('linter_mess.ts')) {
-          // If limit is missing or undefined, it defaults to reading the whole file (or a very large chunk)
-          // We want to force it to be specific.
-          expect(
-            args.limit,
-            'Agent read the entire file (missing limit) instead of searching/partial reading',
-          ).toBeDefined();
-
-          // Even if defined, it shouldn't be the file size (4000)
-          expect(args.limit, 'Agent read too many lines at once').toBeLessThan(
-            1000,
-          );
-        }
-      }
-
-      // 2. Verify search was likely used (good behavior)
-      const searchCalls = logs.filter(
-        (log) => log.toolRequest?.name === GREP_TOOL_NAME,
-      );
-      expect(
-        searchCalls.length,
-        'Agent should have searched for "var" first',
-      ).toBeGreaterThan(0);
-
-      // 3. Verify the file content was actually updated (using read_file to check disk state from test rig)
-      // Since we can't easily check disk state inside assert without 'fs', we rely on the tool execution logs or success.
-      // But for this behavior test, the read pattern is the most important part.
-    },
-  });
-
   evalTest('ALWAYS_PASSES', {
     name: 'should use ranged read when specific line is targeted',
     files: {
@@ -99,9 +38,14 @@ describe('optimization_evals', () => {
         'Agent should have used read_file to check context',
       ).toBeGreaterThan(0);
 
+      let targetedReadFound = false;
+      let totalLinesRead = 0;
+
       for (const call of readCalls) {
         const args = JSON.parse(call.toolRequest.args);
         if (args.file_path.includes('linter_mess.ts')) {
+          totalLinesRead += args.limit ?? 4000;
+
           expect(
             args.limit,
             'Agent read the entire file (missing limit) instead of using ranged read',
@@ -111,21 +55,22 @@ describe('optimization_evals', () => {
             1000,
           );
 
-          // Since the error is at line 3000, efficient reading implies using an offset
-          // unless they grep first (which is also fine, but less direct if line is known).
-          // However, strict ranged read usually means offset is set.
-          // We'll allow either grep OR offset usage.
-          const hasOffset = args.offset !== undefined && args.offset > 2000;
-
-          // If they didn't use offset, they better have searched first or read a small chunk?
-          // Actually if they read line 0-1000, they won't find line 3000.
-          // So if they read the file, they MUST have used offset to see line 3000 without reading the whole thing.
-          expect(
-            hasOffset,
-            'Agent should use offset to read around line 3000',
-          ).toBe(true);
+          if (args.offset !== undefined && args.offset > 2000) {
+            targetedReadFound = true;
+          }
         }
       }
+
+      // Ranged read shoud be frugal and just enough to satisfy the task at hand.
+      expect(
+        totalLinesRead,
+        'Agent read more of the file than expected',
+      ).toBeLessThan(500);
+
+      expect(
+        targetedReadFound,
+        'Agent should have used offset to read around line 3000 at least once',
+      ).toBe(true);
     },
   });
 });