Preempt to a higher-priority account when one is available

src/account-manager.js

@@ -65,7 +65,13 @@ export class AccountManager {
       if (next) return next;
     }
     if (this._isAvailable(current)) {
-      return current;
+      // A strictly higher-priority (lower value) available account preempts a
+      // healthy current one. Within the same priority tier we stay put, so the
+      // common case (all accounts at the default priority 0) is unchanged and
+      // never thrashes — preemption only triggers when priorities differ.
+      const betterExists = this.accounts.some(a =>
+        this._isAvailable(a) && (a.priority || 0) < (current.priority || 0));
+      return betterExists ? this._selectNext() : current;
     }
     return this._selectNext();
   }

test/rotation-priority.test.js

@@ -56,3 +56,26 @@ test('exhausted highest-priority account is skipped, next priority wins', () =>
   exhaust(am, 0);
   assert.equal(am._selectNext().name, 'b');
 });
+
+test('getActiveAccount preempts a healthy current account for a higher-priority one', () => {
+  const am = new AccountManager([oauth('a', { priority: 0 }), oauth('b', { priority: 1 })], 0.98);
+  am.currentIndex = 1; // currently on the lower-priority account
+  assert.equal(am.getActiveAccount().name, 'a');
+  assert.equal(am.currentIndex, 0);
+});
+
+test('getActiveAccount stays sticky within the same priority tier (no thrash)', () => {
+  const am = new AccountManager([oauth('a', { priority: 0 }), oauth('b', { priority: 0 })], 0.98);
+  am.currentIndex = 0;
+  // b has a sooner weekly reset, but same priority → must NOT switch away from a.
+  am.accounts[0].quota.unified7dReset = 5000;
+  am.accounts[1].quota.unified7dReset = 1000;
+  assert.equal(am.getActiveAccount().name, 'a');
+  assert.equal(am.currentIndex, 0);
+});
+
+test('common case: all-equal priority leaves getActiveAccount on the healthy current account', () => {
+  const am = new AccountManager([oauth('a'), oauth('b'), oauth('c')], 0.98);
+  am.currentIndex = 2;
+  assert.equal(am.getActiveAccount().name, 'c'); // unchanged — no preemption when priorities tie
+});