text: 
  import * as Y from 'yjs'
  import * as t from 'lib0/testing'
  import * as awareness from './awareness'
  
  /**
   * @param {t.TestCase} tc
   */
  export const testAwareness = tc => {
    const doc1 = new Y.Doc()
    doc1.clientID = 0
    const doc2 = new Y.Doc()
    doc2.clientID = 1
    const aw1 = new awareness.Awareness(doc1)
    const aw2 = new awareness.Awareness(doc2)
    aw1.on('update', /** @param {any} p */ ({ added, updated, removed }) => {
      const enc = awareness.encodeAwarenessUpdate(aw1, added.concat(updated).concat(removed))
      awareness.applyAwarenessUpdate(aw2, enc, 'custom')
    })
    let lastChangeLocal = /** @type {any} */ (null)
    aw1.on('change', /** @param {any} change */ change => {
      lastChangeLocal = change
    })
    let lastChange = /** @type {any} */ (null)
    aw2.on('change', /** @param {any} change */ change => {
      lastChange = change
    })
    aw1.setLocalState({ x: 3 })
    t.compare(aw2.getStates().get(0), { x: 3 })
    t.assert(/** @type {any} */ (aw2.meta.get(0)).clock === 1)
    t.compare(lastChange.added, [0])
    // When creating an Awareness instance, the the local client is already marked as available, so it is not updated.
    t.compare(lastChangeLocal, { added: [], updated: [0], removed: [] })
  
    // update state
    lastChange = null
    lastChangeLocal = null
    aw1.setLocalState({ x: 4 })
    t.compare(aw2.getStates().get(0), { x: 4 })
    t.compare(lastChangeLocal, { added: [], updated: [0], removed: [] })
    t.compare(lastChangeLocal, lastChange)
  
    lastChange = null
    lastChangeLocal = null
    aw1.setLocalState({ x: 4 })
    t.assert(lastChange === null)
    t.assert(/** @type {any} */ (aw2.meta.get(0)).clock === 3)
    t.compare(lastChangeLocal, lastChange)
    aw1.setLocalState(null)
    t.assert(lastChange.removed.length === 1)
    t.compare(aw1.getStates().get(0), undefined)
    t.compare(lastChangeLocal, lastChange)
  }
  