Import AITURK IDE 1.0.0-beta.1 from Hermes 63279301; preserve MIT license

ui-tui/src/lib/resizeCoalescer.ts

@@ -0,0 +1,56 @@
+export interface ResizeCoalescer {
+  /** Call on each terminal 'resize' event. */
+  schedule: () => void
+  /** Drop any pending trailing reflow (effect cleanup). */
+  cancel: () => void
+}
+
+/**
+ * Leading + trailing throttle for terminal-resize bursts.
+ *
+ * A drag-resize emits a burst of 'resize' events; reflowing on every one
+ * remounts the visible transcript rows each tick (they're keyed on cols so
+ * yoga re-measures off live geometry), turning a smooth drag into a
+ * flickering remount storm.
+ *
+ * `schedule()` reflows immediately on the first event (the drag stays
+ * responsive), then collapses subsequent events to at most one `reflow()`
+ * per `intervalMs`, and always fires a trailing `reflow()` so the final
+ * width lands exactly. `cancel()` clears a pending trailing reflow.
+ *
+ * Uses `Date.now()` + `setTimeout` directly so it is deterministically
+ * testable under fake timers.
+ */
+export function createResizeCoalescer(reflow: () => void, intervalMs: number): ResizeCoalescer {
+  // -Infinity (not 0) so the first schedule() always satisfies the
+  // elapsed >= interval leading-edge check regardless of the wall clock.
+  let lastReflow = Number.NEGATIVE_INFINITY
+  let trailing: ReturnType<typeof setTimeout> | undefined
+
+  const run = () => {
+    lastReflow = Date.now()
+    reflow()
+  }
+
+  return {
+    schedule() {
+      const elapsed = Date.now() - lastReflow
+
+      clearTimeout(trailing)
+      trailing = undefined
+
+      if (elapsed >= intervalMs) {
+        run()
+      } else {
+        trailing = setTimeout(() => {
+          trailing = undefined
+          run()
+        }, intervalMs - elapsed)
+      }
+    },
+    cancel() {
+      clearTimeout(trailing)
+      trailing = undefined
+    }
+  }
+}