fix(engine): detect maxIterations/percentComplete changes in progressChanged (#9323)

packages/loopover-engine/src/loop-progress.ts

@@ -78,13 +78,21 @@ function activityChanged(prev: readonly LoopProgressActivity[], next: readonly L
 
 /** True when `next` differs from `prev` in a way worth pushing to the customer — so the surface streams
  *  ON CHANGE instead of polling on a fixed interval (#4800's acceptance). A null `prev` (the first snapshot)
- *  always pushes. Compares the displayed axes: phase, status, iteration, and the activity tail's contents. */
+ *  always pushes. Compares every displayed axis: phase, status, iteration, the iteration budget and the
+ *  percent through it (maxIterations/percentComplete), and the activity tail's contents.
+ *
+ *  maxIterations/percentComplete are displayed too but were originally left out of the diff (#9323): raising
+ *  the iteration budget mid-run (#6773's percentComplete is `iteration / maxIterations`) moves the customer's
+ *  percent while phase/status/iteration/activity all hold, so a budget-only change silently went unpushed and
+ *  the progress bar went stale. Both are compared so any change to a shown number streams. */
 export function progressChanged(prev: ProgressSnapshot | null, next: ProgressSnapshot): boolean {
   if (prev === null) return true;
   return (
     prev.phase !== next.phase ||
     prev.status !== next.status ||
     prev.iteration !== next.iteration ||
+    prev.maxIterations !== next.maxIterations ||
+    prev.percentComplete !== next.percentComplete ||
     activityChanged(prev.recentActivity, next.recentActivity)
   );
 }

test/unit/loop-progress.test.ts

@@ -5,6 +5,7 @@ import {
   MAX_PROGRESS_ACTIVITY,
   type LoopProgressActivity,
   type LoopProgressState,
+  type ProgressSnapshot,
 } from "../../packages/loopover-engine/src/loop-progress";
 
 function running(overrides: Partial<LoopProgressState> = {}): LoopProgressState {
@@ -67,6 +68,35 @@ describe("progressChanged — push on change, not on a fixed interval (#4800)",
     expect(progressChanged(base, buildProgressSnapshot(running({ recentActivity: [{ step: "a" }] })))).toBe(false);
   });
 
+  // #9323: maxIterations and percentComplete are displayed axes too, but were left out of the diff. Raising the
+  // iteration budget mid-run moves the customer's percent while phase/status/iteration/activity all hold — that
+  // must still push, or the progress bar shows a stale percent.
+  it("REGRESSION (#9323): pushes when only the iteration budget (maxIterations, and so percentComplete) changes", () => {
+    const widerBudget = buildProgressSnapshot(running({ maxIterations: 10, recentActivity: [{ step: "a" }] }));
+    // Everything `base` displays is held constant except the budget (5→10) and its derived percent (40→20).
+    expect(base).toMatchObject({ maxIterations: 5, percentComplete: 40 });
+    expect(widerBudget).toMatchObject({ phase: base.phase, status: base.status, iteration: base.iteration, maxIterations: 10, percentComplete: 20 });
+    expect(widerBudget.recentActivity).toEqual(base.recentActivity);
+    expect(progressChanged(base, widerBudget)).toBe(true);
+  });
+
+  // #9323 regression guard against over-triggering: identical on ALL six displayed axes (including the two new
+  // ones) must still not push.
+  it("does not push when maxIterations and percentComplete are identical alongside the other axes", () => {
+    const same = buildProgressSnapshot(running({ recentActivity: [{ step: "a" }] }));
+    expect(same).toMatchObject({ maxIterations: base.maxIterations, percentComplete: base.percentComplete });
+    expect(progressChanged(base, same)).toBe(false);
+  });
+
+  // #9323: percentComplete is compared as its own axis, so a change to just that shown number still pushes even
+  // if maxIterations is unchanged. It is normally derived from iteration/maxIterations, so isolate it by building
+  // the snapshot directly rather than through buildProgressSnapshot.
+  it("REGRESSION (#9323): pushes when only percentComplete differs, with maxIterations and every other axis held", () => {
+    const shiftedPercent: ProgressSnapshot = { ...base, percentComplete: (base.percentComplete ?? 0) + 1 };
+    expect(shiftedPercent.maxIterations).toBe(base.maxIterations);
+    expect(progressChanged(base, shiftedPercent)).toBe(true);
+  });
+
   // #6171: the tail is capped, so past the cap every new event evicts the oldest and the LENGTH stops moving.
   // A length-only check went permanently blind here — exactly on the long runs that stream the most.
   describe("activity tail at its cap (#6171)", () => {