fix: handle request errors when fetching CODEOWNERS

getCodeOwnersFile() listened for an 'err' event on the https request,
which ClientRequest never emits; failures are emitted as 'error'. Any
network-level failure (DNS, ECONNRESET, socket hang up, TLS) therefore
had no listener, was thrown as an uncaught exception and terminated the
bot through the uncaughtException handler in server.js, instead of
rejecting the promise and letting the surrounding Aigle.retry() retry.

Listen for 'error' on the request, also reject on errors emitted by the
response stream (e.g. a connection dropped mid-body), and drain the
body of non-200 responses so the socket is released.

Add a unit test that makes the request fail at the network level and
expects getCodeOwnersFile() to reject; it fails with an uncaught
exception without this change.

Fixes: #705
Signed-off-by: NopeCharon <115794254+NopeCharon@users.noreply.github.com>

Author: NopeCharon

lib/node-repo.js

@@ -117,6 +117,8 @@ function getCodeOwnersFile (url, { logger }) {
   return new Promise((resolve, reject) => {
     https.get(url, (res) => {
       if (res.statusCode !== 200) {
+        // discard the response body so the socket is released
+        res.resume()
         logger.error(`Status code: ${res.statusCode}`, 'Error retrieving OWNERS')
         return reject(res.statusCode)
       }
@@ -127,7 +129,11 @@ function getCodeOwnersFile (url, { logger }) {
       res.on('end', () => {
         return resolve(body)
       })
-    }).on('err', (err) => {
+      res.on('error', (err) => {
+        logger.error(err, 'Error retrieving OWNERS')
+        return reject(err)
+      })
+    }).on('error', (err) => {
       logger.error(err, 'Error retrieving OWNERS')
       return reject(err)
     })

test/unit/node-repo-owners.test.js

@@ -169,6 +169,28 @@ test('getCodeOwnersFile fail', async (t) => {
   scope.done()
 })
 
+test('getCodeOwnersFile network error', async (t) => {
+  const options = {
+    owner: 'nodejs',
+    repo: 'node-auto-test-6',
+    prId: 12347,
+    logger: { info: () => {}, error: () => {}, debug: () => {}, child: function () { return this } },
+    retries: 1,
+    defaultBranch: 'main',
+    retryInterval: 10
+  }
+
+  const base = 'https://localhost'
+  const filePath = '/CODEOWNERS'
+  const url = `${base}${filePath}`
+  const scope = nock(base)
+    .get(filePath)
+    .replyWithError('socket hang up')
+
+  await t.assert.rejects(getCodeOwnersFile(url, options), { message: 'socket hang up' })
+  scope.done()
+})
+
 test('pingOwners success', async (t) => {
   const options = {
     owner: 'nodejs',