MutableNetwork.hasEdgeConnecting throw IllegalArgumentException when node are missing

[fathzer]

According to the javadoc, the hasEdgeConnecting method is equivalent to nodes().contains(nodeU) && successors(nodeU).contains(nodeV).
But, unlike this expression, it throws an exception if the nodes are unknown.
Here is a simple demonstration

import com.google.common.graph.MutableNetwork;
import com.google.common.graph.NetworkBuilder;

public class Bug {
	public static void main(String[] args) {
		final MutableNetwork<String, String> graph = NetworkBuilder.undirected().allowsParallelEdges(false).build();
		// Foolowing line prints false
		System.out.println(graph.nodes().contains("1") && graph.successors("1").contains("2"));
		// Next should print false but throws an IllegalArgumentException
		System.out.println(graph.hasEdgeConnecting("1", "2"));
	}
}

version guava-28.1-jre

[nick-someone]

It looks like a bit subtle, but successors(nodeU).contains(nodeV) throws an IllegalArgumentException when nodeU is not in the network (which is the actual behavior you're seeing here).

However, you're right that the short-circuiting behavior of && isn't replicating here. That seems like an important part of the documented behavior :). FWIW, it appears to also throw an IllegalArgumentException even if "1" is in the network but "2" isn't.

[jrtom]

This is just a straight-up bug on our parts; I'm coding up a fix now.

The problem originates in the fact that hasEdgeConnecting() is actually (in effect) calling edgesConnecting().isEmpty(). This seems reasonable on the face of it, but edgesConnecting(u, v) has the contract that it throws if either u or v are not in the graph; this is consistent with the contracts for the other Set-returning accessors, but it's not what we want for boolean-returning queries like hasEdgeConnecting().

Sorry about that; thanks for the catch. :)

[jrtom]

I've submitted an internal fix; this should be propagating externally soon.

[jrtom]

This is fixed in v28.2: https://github.com/google/guava/releases/tag/v28.2