nes: fix off by one

Author: ulugbekna

src/extension/xtab/common/promptCrafting.ts

@@ -693,7 +693,7 @@ export function clipPreservingRange(
 	);
 
 	const linesOffsetStart = firstPageIdx * pageSize;
-	const linesOffsetEndExcl = lastPageIdx * pageSize + pageSize + 1 /* because excl */;
+	const linesOffsetEndExcl = lastPageIdx * pageSize + pageSize;
 
 	return Result.ok(new OffsetRange(linesOffsetStart, linesOffsetEndExcl));
 }

src/extension/xtab/test/common/promptCrafting.spec.ts

@@ -197,8 +197,27 @@ suite('Paged clipping - current file', () => {
 			10,
 			{ ...opts, maxTokens: 20 },
 		);
-		assert(result.isError());
-		expect(result.err).toMatchInlineSnapshot(`"outOfBudget"`);
+		expect(result).toMatchInlineSnapshot(`
+			ResultOk {
+			  "val": {
+			    "nLines": 6,
+			    "taggedCurrentFileContent": "21
+			<area_around_code_to_edit>
+			22
+			23
+			<code_to_edit>
+			24
+			25
+			<code_to_edit>
+			26
+			</area_around_code_to_edit>
+			27
+			28
+			29
+			30",
+			  },
+			}
+		`);
 	});