How to fix Cannot find module 'typescript' in Angular 4?

Question

I generated Angular 4 app 3 weeks ago using the @angular/cli. After 2 weeks, I tried to run it with the command line \"ng serve\" but I am prompted an error bel

Answer 1

Run 'npm install' it will install all necessary pkg .

Answer 2

If you use yarn instead of npm, you can install typescript package for that workspace by running:

yarn add typescript

or you can install it globally by running:

sudo yarn global add typescript

to be available for any project.

Answer 3

If you have cloned your project from git or somewhere then first, you should type npm install.

Answer 4

I had a very similar problem after moving a working project to a new subdirectory on my file system. It turned out I had failed to move the file named .angular-cli.json to the subfolder along with everything else. After noticing that and moving the file into the subdirectory, all was back to normal.

Answer 5

For me just running the below command is not enough (though a valid first step):

npm install -g typescript

The following command is what you need (I think deleting node_modules works too, but the below command is quicker)

npm link typescript