/// <summary>
/// Validates the mapping/configuration of the model for cycles.
/// </summary>
/// <param name="model">The model to validate.</param>
/// <param name="logger">The logger to use.</param>
protected virtual void ValidateNoCycles(
IModel model,
IDiagnosticsLogger <DbLoggerCategory.Model.Validation> logger)
{
var graph = new Multigraph <IEntityType, IForeignKey>();
foreach (var entityType in model.GetEntityTypes())
{
var primaryKey = entityType.FindPrimaryKey();
if (primaryKey == null)
{
continue;
}
foreach (var foreignKey in entityType.GetForeignKeys())
{
var principalType = foreignKey.PrincipalEntityType;
if (!foreignKey.PrincipalKey.IsPrimaryKey() ||
!PropertyListComparer.Instance.Equals(foreignKey.Properties, primaryKey.Properties) ||
foreignKey.PrincipalEntityType.IsAssignableFrom(entityType))
{
continue;
}
graph.AddVertex(entityType);
graph.AddVertex(principalType);
graph.AddEdge(entityType, principalType, foreignKey);
}
}
graph.TopologicalSort(
tryBreakEdge: null,
formatCycle: c => c.Select(d => d.Item1.DisplayName()).Join(" -> "),
c => CoreStrings.IdentifyingRelationshipCycle(c));
}
public void AddEdges_throws_on_verticies_not_in_the_graph()
{
var vertexOne = new Vertex {
Id = 1
};
var vertexTwo = new Vertex {
Id = 2
};
var edgeOne = new Edge {
Id = 1
};
var graph = new Multigraph <Vertex, Edge>();
graph.AddVertex(vertexOne);
Assert.Equal(
Strings.GraphDoesNotContainVertex(vertexTwo),
Assert.Throws <InvalidOperationException>(() => graph.AddEdges(vertexOne, vertexTwo, new[] { edgeOne })).Message);
Assert.Equal(
Strings.GraphDoesNotContainVertex(vertexTwo),
Assert.Throws <InvalidOperationException>(() => graph.AddEdges(vertexTwo, vertexOne, new[] { edgeOne })).Message);
}
public void TopologicalSort_on_self_ref_can_break_cycle()
{
var vertexOne = new Vertex {
Id = 1
};
var edgeOne = new Edge {
Id = 1
};
var graph = new Multigraph <Vertex, Edge>();
graph.AddVertex(vertexOne);
// 1 -> {1}
graph.AddEdge(vertexOne, vertexOne, edgeOne);
Assert.Equal(
new[] { vertexOne },
graph.TopologicalSort(
(from, to, edges) =>
(from == vertexOne) &&
(to == vertexOne) &&
(edges.Intersect(new[] { edgeOne }).Count() == 1)).ToArray());
}
public void AddVertex_adds_a_vertex()
{
var vertexOne = new Vertex {
Id = 1
};
var vertexTwo = new Vertex {
Id = 2
};
var graph = new Multigraph <Vertex, Edge>();
graph.AddVertex(vertexOne);
graph.AddVertex(vertexTwo);
Assert.Equal(2, graph.Vertices.Count());
Assert.Equal(2, graph.Vertices.Intersect(new[] { vertexOne, vertexTwo }).Count());
}