Feature: Edges have a "bundled" getter for when they represents a bundled dependency

[kumavis]

when analyzing a dep graph its useful to see if an Edge is a bundledDependencies edge. this is especially useful when trying to understand the provenance of a package's content.

This PR adds a bundled getter property to the Edge.prototype which returns true if its a bundledDependencies edge or not.

References

Related to npm/cli#2750

[isaacs]

Since it's only checking that the edge.from is the bundler (and not that the node is in a bundle at all), it would be more efficient to check edge.from.package.bundleDependencies.includes(edge.name). This would also mark the edge as a bundling edge, even if it is not resolved.

[isaacs]

This would be really handy to make the code in a few places easier to follow, I like the idea a lot.

[kumavis]

yeah sounds good, I was thrown off by this part and wasn't sure what the appropriate check was

arborist/lib/node.js

Lines 435 to 440 in 6f99a5e

	const eBundler = edge.from.getBundler(path)
	if (!eBundler)
	continue
	if (eBundler === parent)
	return eBundler

any situation where it would be bundled but this.to.name would differ from whats in this.from.package.bundleDependencies?

[kumavis]

neat. im happy with this