/// <summary>
/// Given:
/// - a file-to-file map (<paramref name="file2file"/>), and
/// - indexes of changed nodes (<paramref name="changed"/>)
/// computes
/// - downstream nodes (and asserts they match <paramref name="expectedDownstream"/>
/// - upsteram nodes (and asserts they match <paramref name="expectedUpstream"/>
/// - indirect upstream nodes (and asserts they match <paramref name="expectedIndirectUpstream"/>
/// - all affected nodes (and asserts they match <paramref name="expectedAffected"/>
///
/// Definitions:
/// - 'downstream' nodes: all nodes reachable from <paramref name="changed"/> (excluding the
/// changed nodes themselves) by following the reverse edges in <paramref name="file2file"/>
/// - 'upstream' nodes: all nodes reachable from <paramref name="changed"/> (excluding the
/// changed nodes themselves) by following the edges in <paramref name="file2file"/>
/// - 'affected' nodes: upstream of 'changed' + 'downstream' nodes, including the changed and
/// downstream nodes themselves
/// - 'indirect upstream' nodes: 'affected' nodes that are neither 'changed' or 'upstream' or 'downstream'
/// </summary>
/// <remarks>
/// Some remarks about the notation in the comments below:
/// - the '^' means transitive closure
/// - the '*' means reflexive transitive closure
/// - the '.' means relational join
/// For example
/// - changed.^Edges means all reachable nodes from 'changed' by following 'Edges', excluding the nodes in 'changed'
/// - changed.*Edges means all reachable nodes from 'changed' by following 'Edges', including the nodes in 'changed'.
/// </remarks>
private void ComputeAndCheckSpecStates(SimpleGraph file2file, int[] changed, int[] expectedDownstream,
int[] expectedUpstream, int[] expectedIndirectUpstream, int[] expectedAffected)
{
// downstream = changed.^reverseEdges
var downstream = file2file.ComputeDownstream(changed);
XAssert.AreSetsEqual(expectedDownstream, downstream, expectedResult: true, format: "Downstream nodes don't match");
// upstream = changed.^edges
var upstream = file2file.ComputeUpstream(changed);
XAssert.AreSetsEqual(expectedUpstream, upstream, expectedResult: true, format: "Upstream nodes don't match");
// allAffected = (changed.*reverseEdges).*edges
var allAffected = file2file.ComputeReflexiveUpstream(file2file.ComputeReflexiveDownstream(changed));
XAssert.AreSetsEqual(expectedAffected, allAffected, expectedResult: true, format: "Affected nodes don't match");
// indirectUpstream = allAffected - changed - upstream - downstream
var indirectUpstream = allAffected.Except(changed).Except(upstream).Except(downstream);
XAssert.AreSetsEqual(expectedIndirectUpstream, indirectUpstream, expectedResult: true, format: "Indirect upstream nodes don't match");
}