Fix Kattis parser when sample has no input

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 - Added support for the codeforces.net mirror of Codeforces and fixed support for the codeforc.es mirror on problem pages
 - Fixed the Lanqiao problem parser
+- Fixed the Kattis parser for samples containing only output
 
 ## [2.57.1](https://github.com/jmerle/competitive-companion/releases/tag/2.57.1) (2024-11-15)
 - Added the `X-Competitive-Companion` header to HTTP requests sent by Competitive Companion to indicate to the receiving end that the request is coming from Competitive Companion (thanks [@touhidurrr](https://github.com/touhidurrr))

src/models/Test.ts

@@ -20,6 +20,6 @@ export class Test {
         .trimEnd();
     }
 
-    return data.endsWith('\n') ? data : data + '\n';
+    return data.endsWith('\n') || data.length === 0 ? data : data + '\n';
   }
 }

src/parsers/problem/KattisProblemParser.ts

@@ -30,10 +30,13 @@ export class KattisProblemParser extends Parser {
     task.setMemoryLimit(parseInt(/(\d+) MB/.exec(limitsStr)[1], 10));
 
     elem.querySelectorAll('.sample').forEach(table => {
-      const blocks = table.querySelectorAll('pre');
-      if (blocks.length > 0) {
-        task.addTest(blocks[0].textContent, blocks.length > 1 ? blocks[1].textContent : '', false);
-      }
+      const inputBlock = table.querySelector('tbody > tr:last-child > td:first-child > pre');
+      const outputBlock = table.querySelector('tbody > tr:last-child > td:last-child > pre');
+
+      const input = inputBlock !== null ? inputBlock.textContent : '';
+      const output = outputBlock !== null ? outputBlock.textContent : '';
+
+      task.addTest(input, output, false);
     });
 
     return task.build();