Typescript error when migrating from Angular 2 to 4

Question

I'm looking to migrate my angular 2 project to angular 4. I ran the command:

npm install @angular/{common,compiler,compiler-cli,core,forms,http,platform-browser,platform-browser-dynamic,platform-server,router,animations}@latest typescript@latest --save

Found at this official link: http://angularjs.blogspot.in/2017/03/angular-400-now-available.html

But then this typescript error shows up:

├── @angular/[email protected] 
├─┬ @angular/[email protected]
│ └── [email protected] 
├── @angular/[email protected] 
├── @angular/[email protected] 
├─┬ @angular/[email protected]  invalid
│ └─┬ @angular/[email protected] 
│   └── [email protected] 
├── @angular/[email protected] 
├── @angular/[email protected] 
├── @angular/[email protected] 
├── @angular/[email protected] 
├── @angular/[email protected] 
├─┬ @angular/[email protected] 
│ ├── [email protected] 
│ └── [email protected] 
├── @angular/[email protected] 
├── [email protected]  invalid
└── UNMET PEER DEPENDENCY [email protected]

npm WARN @angular/[email protected] requires a peer of zone.js@^0.8.4 but none was installed.

Answer 1

Its a warning telling to to install zone.js . Try using ng serve if you are using cli to check if the application starts.

note - Angular 4 will support only TypeScript 2.1 . hope you have updated ts version

Answer 2

It's only a warn not error. You need also update zone.js to resolve this warn.