fix(core): refresh dimensions after resize debounce

Author: dajiaohuang

packages/core/src/renderer.ts

@@ -893,9 +893,7 @@ export class CliRenderer extends EventEmitter implements RenderContext {
 
   private _useConsole: boolean = true
   private sigwinchHandler: () => void = (() => {
-    const width = this.stdout.columns || 80
-    const height = this.stdout.rows || 24
-    this.handleResize(width, height)
+    this.handleResize()
   }).bind(this)
   private _capabilities: TerminalCapabilities | null = null
   private _latestPointer: { x: number; y: number } = { x: 0, y: 0 }
@@ -3814,10 +3812,16 @@ export class CliRenderer extends EventEmitter implements RenderContext {
     }
   }
 
-  private handleResize(width: number, height: number): void {
+  private handleResize(): void {
     if (this._isDestroyed) return
+    const resize = () => {
+      const stdout = this.stdout as NodeJS.WriteStream & { _refreshSize?: () => void }
+      // PTY bridges can deliver SIGWINCH before the stream's cached dimensions reflect the new window size.
+      stdout._refreshSize?.()
+      this.processResize(stdout.columns || 80, stdout.rows || 24)
+    }
     if (this._splitHeight > 0) {
-      this.processResize(width, height)
+      resize()
       return
     }
 
@@ -3828,7 +3832,7 @@ export class CliRenderer extends EventEmitter implements RenderContext {
 
     this.resizeTimeoutId = this.clock.setTimeout(() => {
       this.resizeTimeoutId = null
-      this.processResize(width, height)
+      resize()
     }, this.resizeDebounceDelay)
   }
 

packages/core/src/tests/renderer.clock.test.ts

@@ -1,5 +1,6 @@
 import { afterEach, beforeEach, expect, test } from "bun:test"
 import { SystemClock } from "../lib/clock.js"
+import { CliRenderEvents } from "../renderer.js"
 import { createTestRenderer, type TestRenderer } from "../testing/test-renderer.js"
 import { ManualClock } from "../testing/manual-clock.js"
 
@@ -33,6 +34,25 @@ test("renderer init does not pre-schedule frames when size is unchanged", async
   expect(frameCalls).toBe(0)
 })
 
+test("SIGWINCH refreshes terminal dimensions after the resize debounce", () => {
+  const stdout = (renderer as unknown as { stdout: { columns: number; rows: number; _refreshSize?: () => void } })
+    .stdout
+  const dimensions: Array<[number, number]> = []
+  renderer.on(CliRenderEvents.RESIZE, (width, height) => dimensions.push([width, height]))
+  stdout._refreshSize = () => {
+    stdout.columns = 60
+    stdout.rows = 18
+  }
+
+  // @ts-expect-error - invoke the private signal handler in a regression test
+  renderer.sigwinchHandler()
+  clock.advance(100)
+
+  expect(renderer.width).toBe(60)
+  expect(renderer.height).toBe(18)
+  expect(dimensions).toEqual([[60, 18]])
+})
+
 test("requestRender() does not stall after a backward clock jump", async () => {
   clock.setTime(10_000)
   // @ts-expect-error - inspect private renderer timing state in regression test

packages/core/src/tests/renderer.console-startup.test.ts

@@ -135,7 +135,10 @@ test("CliRenderer uses its shared clock for debounced resize", async () => {
   })
 
   renderer = result.renderer
-  ;(renderer as any).handleResize(70, 30)
+  const stdout = (renderer as unknown as { stdout: { columns: number; rows: number } }).stdout
+  stdout.columns = 70
+  stdout.rows = 30
+  ;(renderer as unknown as { handleResize: () => void }).handleResize()
 
   expect(renderer.width).toBe(40)
   expect(renderer.height).toBe(20)