fix: address triaged review findings

app/json.test.js

@@ -6,6 +6,7 @@ import path from 'path';
 import { stripCodeFence, repairJSONArrayWithAI, validateJSONArrayFile, ensureJSONArrayFileExists } from './json.js';
 
 describe('json helpers', () => {
+  const MAX_JSON_BYTES = 1024 * 1024;
   let workspace;
 
   beforeEach(() => {
@@ -76,6 +77,16 @@ describe('json helpers', () => {
     assert.equal(fs.readFileSync(fullPath, 'utf8'), '[]\n');
   });
 
+  it('reads a valid JSON file whose size equals the maximum limit', async () => {
+    const fullPath = path.join(workspace, '.gitea/ai-review/findings.json');
+    fs.mkdirSync(path.dirname(fullPath), { recursive: true });
+    fs.writeFileSync(fullPath, `[]${' '.repeat(MAX_JSON_BYTES - 2)}`, 'utf8');
+
+    const result = await validateJSONArrayFile(fullPath, '.gitea/ai-review/findings.json');
+
+    assert.deepEqual(result, { exists: true, valid: true, repaired: false });
+  });
+
   it('repairs invalid JSON using AI output and rewrites the file', async () => {
     const fullPath = path.join(workspace, '.gitea/ai-review/findings.json');
     fs.mkdirSync(path.dirname(fullPath), { recursive: true });
@@ -90,6 +101,20 @@ describe('json helpers', () => {
     assert.equal(fs.readFileSync(fullPath, 'utf8'), '[{"fixed":true}]\n');
   });
 
+  it('preserves a trailing newline returned by AI repair', async () => {
+    const fullPath = path.join(workspace, '.gitea/ai-review/findings.json');
+    fs.mkdirSync(path.dirname(fullPath), { recursive: true });
+    fs.writeFileSync(fullPath, '{broken', 'utf8');
+
+    const result = await validateJSONArrayFile(fullPath, '.gitea/ai-review/findings.json', async (_fullPath, _label, original) => {
+      assert.equal(original, '{broken');
+      return '[{"fixed":true}]\n';
+    });
+
+    assert.deepEqual(result, { exists: true, valid: true, repaired: true });
+    assert.equal(fs.readFileSync(fullPath, 'utf8'), '[{"fixed":true}]\n');
+  });
+
   it('throws when AI repair fails', async () => {
     const fullPath = path.join(workspace, '.gitea/ai-review/findings.json');
     fs.mkdirSync(path.dirname(fullPath), { recursive: true });