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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[bug?] Cannot find name 'EventEmitter', property 'channel' of exported interface has or is using private name 'EventEmitter'.","articleBody":"**TypeScript Version:**  3.3.0-dev.20181129\r\n\r\n\u003c!-- Search terms you tried before logging this (so others can find this issue more easily) -->\r\n**Search Terms:**\r\n\r\nThe search results led to issues like this one: https://github.com/Microsoft/TypeScript/issues/6307\r\n\r\n**Code**\r\n\r\n```ts\r\n// ./Events.ts\r\nclass EventTypes {\r\n  constructor(\r\n    public SOME_EVENT: any,\r\n    public OTHER_EVENT: any,\r\n  ) {}\r\n}\r\n\r\nexport const Events = {} as { [k in keyof EventTypes]: k }\r\n\r\nfor (const key in new (EventTypes as any)) {\r\n    Events[key] = key\r\n}\r\n\r\nimport * as events from 'events' // definitions are from `@types/node`\r\n\r\n// our own (better, more type-safe) definition of EventEmitter\r\ninterface BetterEventEmitter\u003cEventTypes> {\r\n  new(): BetterEventEmitter\u003cEventTypes>\r\n  addListener\u003cEventName extends keyof EventTypes> (event: EventName, listener: (arg: EventTypes[EventName]) => void);\r\n  on\u003cEventName extends keyof EventTypes> (event: EventName, listener: (arg: EventTypes[EventName]) => void);\r\n  once\u003cEventName extends keyof EventTypes> (event: EventName, listener: (arg: EventTypes[EventName]) => void);\r\n  removeListener\u003cEventName extends keyof EventTypes> (event: EventName, listener: (arg: EventTypes[EventName]) => void);\r\n  removeAllListeners\u003cEventName extends keyof EventTypes>(event?: EventName): this;\r\n  emit\u003cEventName extends keyof EventTypes>(event: EventName, arg: EventTypes[EventName]): boolean;\r\n  eventNames\u003cEventName extends keyof EventTypes>(): Array\u003cEventName>;\r\n  setMaxListeners(n: number): this;\r\n  getMaxListeners(): number;\r\n  listeners\u003cEventName extends keyof EventTypes>(event: EventName): (arg: EventTypes[EventName]) => void[];\r\n  listenerCount\u003cEventName extends keyof EventTypes>(type: EventName): number;\r\n  prependListener\u003cEventName extends keyof EventTypes>(event: EventName, listener: (arg: EventTypes[EventName]) => void): this;\r\n  prependOnceListener\u003cEventName extends keyof EventTypes>(event: EventName, listener: (arg: EventTypes[EventName]) => void): this;\r\n}\r\n\r\n// override Node EventEmitter with our definition\r\nexport const EventEmitter = events.EventEmitter as unknown as BetterEventEmitter\u003cEventTypes>\r\n```\r\n\r\n```js\r\n// consumer.ts\r\nimport { Events, EventEmitter } from './models/Events' // ERROR: `EventEmitter` is declared but its value is never read.\r\n\r\nconst channel = new EventEmitter // works fine, no error!\r\n\r\nclass Foo {\r\n  channel: EventEmitter // ERROR, Cannot find name 'EventEmitter'\r\n}\r\n\r\nexport interface Bar {\r\n  channel: EventEmitter // ERROR, Cannot find name 'EventEmitter', property 'channel' of exported interface has or is using private name 'EventEmitter'.\r\n}\r\n```\r\n\r\n\r\n**Expected behavior:**\r\n\r\nI expect not to get the `ERROR`s I've marked in the above comments.\r\n\r\n\r\n**Actual behavior:**\r\n\r\nI'm getting those errors.\r\n\r\n**Playground Link:** \u003c!-- A link to a TypeScript Playground \"Share\" link which demonstrates this behavior -->\r\n\r\nI can't put multiple files in Playground or install dependencies.\r\n\r\n**Related Issues:** \u003c!-- Did you find other bugs that looked similar? -->\r\n\r\n\r\nhttps://github.com/Microsoft/TypeScript/issues/6307","author":{"url":"https://github.com/trusktr","@type":"Person","name":"trusktr"},"datePublished":"2018-11-30T02:39:07Z","url":"https://github.com/microsoft/TypeScript/issues/28754"}