We use the npm install
command to install new Node packages locally. The install
command creates a folder called node_modules and copies the package files to it. The install
command also installs all of the dependencies for the given package.
To install Babel, we need to npm install
two packages, babel-cli
and babel-preset-env
. However, npm installs over one hundred other packages that are dependencies for Babel to run properly.
We install Babel with the following two commands:
$ npm install babel-cli -D $ npm install babel-preset-env -D
The babel-cli
package includes command line Babel tools, and the babel-preset-env
package has the code that maps any JavaScript feature, ES6 and above (ES6+), to ES5.
The -D
flag instructs npm to add each package to a property called devDependencies
in package.json. Once the project’s dependencies are listed in devDependencies
, other developers can run your project without installing each package separately. Instead, they can simply run npm install
— it instructs npm to look inside package.json and download all of the packages listed in devDependencies
.
Once you npm install
packages, you can find the Babel packages and all their dependencies in the node_modules folder. The new directory structure contains the following:
project |_ node_modules |___ .bin |___ ... |_ src |___ main.js |_ package.json
The ...
in the file structure above is a placeholder for 100+ packages that npm installed.
Instructions
Enter ls
into the terminal to view the current directory’s file structure.
Use npm with the -D
flag to install the Babel command line package and add it to the devDependencies
property in package.json.
Use npm with the -D
flag to install the Babel preset environment package and add it to the devDependencies
property in package.json.
Enter ls
into the terminal to see the file structure of your current directory. Notice the addition of node_modules.
You can also see the new folder by clicking on the file navigation button above the text editor.