diff --git a/src/test/gitea.test.js b/src/test/gitea.test.js
index 4d819fd..9d92158 100644
--- a/src/test/gitea.test.js
+++ b/src/test/gitea.test.js
@@ -241,4 +241,21 @@ describe('filterDiff', () => {
   it('returns empty string for empty diff', () => {
     assert.equal(filterDiff('', ['.gitea/']), '');
   });
+
+  it('always drops node_modules blocks at any depth (avoids blowing the LLM input limit)', () => {
+    const diff = block('src/node_modules/axios/index.js')
+      + block('node_modules/js-yaml/lib.js')
+      + block('src/main.js');
+    const result = filterDiff(diff, []);
+    assert.ok(!result.includes('node_modules'));
+    assert.ok(result.includes('src/main.js'));
+  });
+
+  it('excludes lock files and dist via the getPRDiff prefix list', () => {
+    const diff = block('src/package-lock.json') + block('dist/index.js') + block('src/main.js');
+    const result = filterDiff(diff, ['package-lock.json', 'src/package-lock.json', 'dist/']);
+    assert.ok(!result.includes('package-lock.json'));
+    assert.ok(!result.includes('dist/'));
+    assert.ok(result.includes('src/main.js'));
+  });
 });