That is how Browserify transforms work, transforms only have an effect directly in the module that is being referenced.
If you want a module in node_modules to have a transform, you’d need to add a package.json to that module and add babelify as a transform for that module too. e.g.
"browserify": {
"transform": [
"babelify"
]
},
inside your package.json plus babelify as a dependency will tell browserify to run the babelify transform on any file inside that module.
Having libs be a folder in node_modules is however probably a bad idea. Generally that folder would have true standalone modules in it. I’d generally say that if the folder can’t be taken and reused elsewhere, then it shouldn’t be in node_modules.
Update
For Babel v6, which was recently released, you will also need to specify which transformations you would like to perform on your code. For that, I would recommend creating a .babelrc file in your root directory to configure Babel.
{
"presets": ["es2015"]
}
and
npm install --save-dev babel-preset-es2015