chore: Add EventEmitter type to FileObject (#9276)

Co-authored-by: Chris Breiding <chrisbreiding@users.noreply.github.com>

cli/types/cypress-eventemitter.d.ts

@@ -6,3 +6,24 @@ interface EventEmitter extends EventEmitter2 {
   emitMap: (eventName: string, args: any[]) => Array<(...args: any[]) => any>
   emitThen: (eventName: string, args: any[]) => Bluebird.BluebirdStatic
 }
+
+// Copied from https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/node/events.d.ts
+// to avoid type conflict.
+interface NodeEventEmitter {
+  addListener(event: string | symbol, listener: (...args: any[]) => void): this
+  on(event: string | symbol, listener: (...args: any[]) => void): this
+  once(event: string | symbol, listener: (...args: any[]) => void): this
+  removeListener(event: string | symbol, listener: (...args: any[]) => void): this
+  off(event: string | symbol, listener: (...args: any[]) => void): this
+  removeAllListeners(event?: string | symbol): this
+  setMaxListeners(n: number): this
+  getMaxListeners(): number
+  listeners(event: string | symbol): Array<(...args: any[]) => void>
+  rawListeners(event: string | symbol): Array<(...args: any[]) => void>
+  emit(event: string | symbol, ...args: any[]): boolean
+  listenerCount(type: string | symbol): number
+  // Added in Node 6...
+  prependListener(event: string | symbol, listener: (...args: any[]) => void): this
+  prependOnceListener(event: string | symbol, listener: (...args: any[]) => void): this
+  eventNames(): Array<string | symbol>
+}

cli/types/cypress.d.ts

@@ -4970,7 +4970,7 @@ declare namespace Cypress {
     dimensions?: Dimensions
   }
 
-  interface FileObject {
+  interface FileObject extends NodeEventEmitter {
     filePath: string
     outputPath: string
     shouldWatch: boolean

cli/types/tests/plugins-config.ts

@@ -28,6 +28,7 @@ const pluginConfig2: Cypress.PluginConfig = (on, config) => {
     file.filePath // $ExpectType string
     file.outputPath // $ExpectType string
     file.shouldWatch // $ExpectType boolean
+    file.getMaxListeners // $ExpectType () => number
 
     return file.outputPath
   })