Can I use latest stable TypeScript or should I stick with the version shipped with AngularCLI?

Question

I wasn't able to find any official recommendation about whether or not upgrade the TypeScript version using the latest stable version available.

The npm version is automatically set in package.json by AngularCLI when creating a new project. It currently is:

"typescript": "~2.4.2"

which means latest 2.4.x version. I was wondering if it would be possible to use the latest stable TypeScript version (and what would be the implications), for example 2.5.x.

Is there a specific reason for setting ~2.4.2 and not "^2.4.2 (which means latest 2.x.x version).

Answer 1

UPDATE 2021:
Checkout this answer Is there a compatibility list for Angular / Angular-CLI and Node.js?

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ORIGINAL ANSWER:
Angular cli may not always support the latest version of TypeScript. There is some issues and PR's related to that:

• Support TypeScript 2.4+
• Typescript 2.4 support
• feat(@angular/cli): support TypeScript 2.4

Also bare in mind that the latest TypeScript version might not be compatible with your Angular version.

If you want to jump to a new/latest TypeScript version - it is at your own risk. Once you do so you have to make sure that it is not breaks anything like tests(ng t), prod build(ng build --prod), etc.

If you stick to the default cli TypeScript version you - are safe.

UPDATE 09 Sept 2017: For anyone who care about using the cli with the latest TypeScript checkout this recent github issue and this particular comment as there was a TypeScript version warning logic introduced in the latest cli 1.4. Here is what it is based on(angular cli team recommendation):

 const versionCombos = [
      { compiler: '>=2.3.1 <3.0.0', typescript: '>=2.0.2 <2.3.0' },
      { compiler: '>=4.0.0 <5.0.0', typescript: '>=2.1.0 <2.4.0' },
      { compiler: '>=5.0.0 <6.0.0', typescript: '>=2.4.0 <2.6.0' }
    ];