public void DirectedGraphAllowsDuplicateEdgesTest()
{
var graph = new DirectedGraph<int>(new[] { 1, 2 });
graph.AddEdge(1, 2);
graph.AddEdge(1, 2);
graph.FindCycle().Should().BeEmpty("Expected no cycle vertices to be found");
}
public void DirectedGraphFindsNoCyclesInAcyclicGraphTest()
{
var graph = new DirectedGraph<int>(new[] { 1, 2, 3, 4, 5 });
// Add non-cyclic edges
graph.AddEdge(1, 2);
graph.AddEdge(1, 5);
graph.AddEdge(2, 3);
graph.AddEdge(2, 4);
graph.AddEdge(3, 4);
graph.AddEdge(3, 5);
graph.AddEdge(1, 5);
graph.FindCycle().Should().BeEmpty("Expected no cycle vertices to be found");
}
public void DirectedGraphFindsCyclesTest()
{
var graph = new DirectedGraph<int>(new[] { 1, 2, 3, 4, 5 });
// Add cycle
graph.AddEdge(1, 2);
graph.AddEdge(2, 3);
graph.AddEdge(3, 1);
// Add extra edges
graph.AddEdge(3, 4);
graph.AddEdge(4, 5);
graph.FindCycle().ShouldBeEquivalentTo(new[] { 1, 2, 3 }, "Expected cycle vertices to be found");
}
static IReadOnlyDictionary<string, IReadOnlyList<Export<IStyleRule, StyleRuleMetadata>>> OrderAndMapRules(
IReadOnlyList<Export<IStyleRule, StyleRuleMetadata>> rules)
{
var languageRuleMap = new Dictionary<string, IReadOnlyList<Export<IStyleRule, StyleRuleMetadata>>>();
ILookup<string, Export<IStyleRule, StyleRuleMetadata>> languageRuleLookup =
rules.ToLookup(r => r.Metadata.LanguageName);
foreach (IGrouping<string, Export<IStyleRule, StyleRuleMetadata>> languageRules in languageRuleLookup)
{
var graph = new DirectedGraph<Export<IStyleRule, StyleRuleMetadata>>(languageRules);
Dictionary<string, Export<IStyleRule, StyleRuleMetadata>> nameRuleMap =
languageRules.ToDictionary(r => r.Metadata.Name);
foreach (Export<IStyleRule, StyleRuleMetadata> languageRule in languageRules)
{
foreach (string afterName in languageRule.Metadata.AfterNames)
{
Export<IStyleRule, StyleRuleMetadata> afterRule;
if (nameRuleMap.TryGetValue(afterName, out afterRule))
{
graph.AddEdge(afterRule, languageRule);
}
}
foreach (string beforeName in languageRule.Metadata.BeforeNames)
{
Export<IStyleRule, StyleRuleMetadata> beforeRule;
if (nameRuleMap.TryGetValue(beforeName, out beforeRule))
{
graph.AddEdge(languageRule, beforeRule);
}
}
}
IReadOnlyList<Export<IStyleRule, StyleRuleMetadata>> cycle = graph.FindCycle();
if (cycle.Count > 0)
{
var ruleNames = String.Join(", ", cycle.Select(r => r.Metadata.Name));
throw new InvalidOperationException($"Dependency cycle exists in rules {ruleNames}");
}
languageRuleMap.Add(languageRules.Key, graph.Sort());
}
return languageRuleMap;
}
