Flaky js-terminal test getRasterizedGlyph

[krassowski]

Description

The js-terminal test fails from time to time with:

  ● terminal/index › Terminal › #session › should set the title when ready

    TypeError: Cannot read properties of undefined (reading 'getRasterizedGlyph')

      at l.cell [as _drawChars] (../../node_modules/xterm-addon-canvas/lib/webpack:/CanvasAddon/src/BaseRenderLayer.ts:374:50)
      at handleGridChanged (../../node_modules/xterm-addon-canvas/lib/webpack:/CanvasAddon/src/TextRenderLayer.ts:246:10)
      at l._drawBackground [as _forEachCell] (../../node_modules/xterm-addon-canvas/lib/webpack:/CanvasAddon/src/TextRenderLayer.ts:162:11)
      at l.cell [as _drawForeground] (../../node_modules/xterm-addon-canvas/lib/webpack:/CanvasAddon/src/TextRenderLayer.ts:243:43)
      at lastRow [as handleGridChanged] (../../node_modules/xterm-addon-canvas/lib/webpack:/CanvasAddon/src/TextRenderLayer.ts:258:36)
      at _.end [as renderRows] (../../node_modules/xterm-addon-canvas/lib/webpack:/CanvasAddon/src/CanvasRenderer.ts:139:34)
      at u.this [as _renderRows] (../../node_modules/xterm/lib/webpack:/xterm/src/browser/services/RenderService.ts:158:9)
      at t.RenderDebouncer.this [as _renderCallback] (../../node_modules/xterm/lib/webpack:/xterm/src/browser/services/RenderService.ts:70:5)
      at t.RenderDebouncer.end [as _innerRefresh] (../../node_modules/xterm/lib/webpack:/xterm/src/browser/RenderDebouncer.ts:73:33)
      at _innerRefresh (../../node_modules/xterm/lib/webpack:/xterm/src/browser/RenderDebouncer.ts:55:11)
      at invokeTheCallbackFunction (../../node_modules/jsdom/lib/jsdom/living/generated/Function.js:19:26)
      at runAnimationFrameCallbacks (../../node_modules/jsdom/lib/jsdom/browser/Window.js:603:13)
      at Timeout._onTimeout (../../node_modules/jsdom/lib/jsdom/browser/Window.js:581:11)

This is due to an upstream bug in xterm.js (xtermjs/xterm.js#4560) which was fixed in https://github.com/xtermjs/xterm.js/releases/tag/5.3.0.

Reproduce

https://github.com/jupyterlab/jupyterlab/actions/runs/7929124004/job/21648754032?pr=15803

Expected behavior

We should upgrade to latest xterm.js as 5.3.0 is now very stable.

Context

• JupyterLab version: 4.1