1 files changed, 64 insertions, 1 deletions
diff --git a/packages/core/src/utils/fileUtils.test.ts b/packages/core/src/utils/fileUtils.test.ts
index b8e75561..ca121bca 100644
--- a/packages/core/src/utils/fileUtils.test.ts
+++ b/packages/core/src/utils/fileUtils.test.ts
@@ -420,7 +420,7 @@ describe('fileUtils', () => {
       expect(result.llmContent).toContain(
         '[File content truncated: showing lines 6-10 of 20 total lines. Use offset/limit parameters to view more.]',
       );
-      expect(result.returnDisplay).toBe('(truncated)');
+      expect(result.returnDisplay).toBe('Read lines 6-10 of 20 from test.txt');
       expect(result.isTruncated).toBe(true);
       expect(result.originalLineCount).toBe(20);
       expect(result.linesShown).toEqual([6, 10]);
@@ -465,7 +465,70 @@ describe('fileUtils', () => {
       expect(result.llmContent).toContain(
         '[File content partially truncated: some lines exceeded maximum length of 2000 characters.]',
       );
+      expect(result.returnDisplay).toBe(
+        'Read all 3 lines from test.txt (some lines were shortened)',
+      );
+      expect(result.isTruncated).toBe(true);
+    });
+
+    it('should truncate when line count exceeds the limit', async () => {
+      const lines = Array.from({ length: 11 }, (_, i) => `Line ${i + 1}`);
+      actualNodeFs.writeFileSync(testTextFilePath, lines.join('\n'));
+
+      // Read 5 lines, but there are 11 total
+      const result = await processSingleFileContent(
+        testTextFilePath,
+        tempRootDir,
+        0,
+        5,
+      );
+
+      expect(result.isTruncated).toBe(true);
+      expect(result.returnDisplay).toBe('Read lines 1-5 of 11 from test.txt');
+    });
+
+    it('should truncate when a line length exceeds the character limit', async () => {
+      const longLine = 'b'.repeat(2500);
+      const lines = Array.from({ length: 10 }, (_, i) => `Line ${i + 1}`);
+      lines.push(longLine); // Total 11 lines
+      actualNodeFs.writeFileSync(testTextFilePath, lines.join('\n'));
+
+      // Read all 11 lines, including the long one
+      const result = await processSingleFileContent(
+        testTextFilePath,
+        tempRootDir,
+        0,
+        11,
+      );
+
+      expect(result.isTruncated).toBe(true);
+      expect(result.returnDisplay).toBe(
+        'Read all 11 lines from test.txt (some lines were shortened)',
+      );
+    });
+
+    it('should truncate both line count and line length when both exceed limits', async () => {
+      const linesWithLongInMiddle = Array.from(
+        { length: 20 },
+        (_, i) => `Line ${i + 1}`,
+      );
+      linesWithLongInMiddle[4] = 'c'.repeat(2500);
+      actualNodeFs.writeFileSync(
+        testTextFilePath,
+        linesWithLongInMiddle.join('\n'),
+      );
+
+      // Read 10 lines out of 20, including the long line
+      const result = await processSingleFileContent(
+        testTextFilePath,
+        tempRootDir,
+        0,
+        10,
+      );
       expect(result.isTruncated).toBe(true);
+      expect(result.returnDisplay).toBe(
+        'Read lines 1-10 of 20 from test.txt (some lines were shortened)',
+      );
     });
 
     it('should return an error if the file size exceeds 20MB', async () => {