The tool might have to recursively parse each file into an AST to find the `require` statements, and potentially apply various transforms (e.g. coffeescript).
On large frontend codebases, these tasks can take an annoyingly long time. Hence, some tools cache (e.g. see browserify vs. watchify).
Yup, it will cache the files automatically and check mtime's so that only the changed files need to be reparsed for dependencies. It ends up being really fast to build once dependencies are installed.
On large frontend codebases, these tasks can take an annoyingly long time. Hence, some tools cache (e.g. see browserify vs. watchify).