Function createCompositionEvent

lib/input-handler.test.ts:90–100

(
  type: 'compositionstart' | 'compositionupdate' | 'compositionend',
  data: string | null
)

// Helper to create mock composition event
function createCompositionEvent(
  type: 'compositionstart' | 'compositionupdate' | 'compositionend',
  data: string | null
): MockCompositionEvent {
  return {
    type,
    data,
    preventDefault: mock(() => {}),
    stopPropagation: mock(() => {}),
  };
}
// Helper to create mock container
function createMockContainer(): MockHTMLElement & {
  _listeners: Map<string, ((e: any) => void)[]>;