npm - What determines the ^ version operator for dependencies in package.json when installing a package?

Question

I noticed in my package.json that some versions have the ^ operator in the dependency version such as:

"prettier": "^2.2.1",

But then some packages do not use this operator such as:

"typescript": "4.1.3"

I know the meaning of the operator but I installed both of these packages via npm install -D <package> and did not modify package.json myself so how was the inclusion of this operator determined?

question from:https://stackoverflow.com/questions/65857549/what-determines-the-version-operator-for-dependencies-in-package-json-when-ins

Answer 1

npm's save-prefix setting affects which prefix is set in package.json when running npm install -D <package> - by default it's set to a caret (^).

So yes it's odd some packages have been prefixed with ^ whilst others haven't.

Perhaps via the npm-config command you inadvertently ran npm config set save-prefix='' (i.e. you set it to nothing).

If you run npm config get save-prefix and it doesn't print ^, then you need to run npm config delete save-prefix to revert to the default ^