public static void GetCyclePaths_GivenEmptyTables_ReturnsEmptyCollection()
{
var cycleDetector = new CycleDetector();
var result = cycleDetector.GetCyclePaths(Array.Empty <IRelationalDatabaseTable>());
Assert.That(result, Is.Empty);
}
/// <summary>
/// Analyses database tables. Reports messages when a set of foreign key relationships forms a cycle.
/// </summary>
/// <param name="tables">A set of database tables.</param>
/// <param name="cancellationToken">A cancellation token used to interrupt analysis.</param>
/// <returns>A set of linting messages used for reporting. An empty set indicates no issues discovered.</returns>
/// <exception cref="ArgumentNullException"><paramref name="tables"/> is <c>null</c>.</exception>
public IAsyncEnumerable <IRuleMessage> AnalyseTables(IEnumerable <IRelationalDatabaseTable> tables, CancellationToken cancellationToken = default)
{
if (tables == null)
{
throw new ArgumentNullException(nameof(tables));
}
var cycleDetector = new CycleDetector();
var cycles = cycleDetector.GetCyclePaths(tables.ToList());
return(cycles.Select(BuildMessage).ToAsyncEnumerable());
}
public async Task RenderAsync(CancellationToken cancellationToken = default)
{
if (!ExportDirectory.Exists)
{
ExportDirectory.Create();
}
var cycleDetector = new CycleDetector();
var cycles = cycleDetector.GetCyclePaths(Tables);
var hasCycles = cycles.Count > 0;
// TODO acutlly use the canellation tokens here
await ExportInsertionOrderAsync(hasCycles, cancellationToken).ConfigureAwait(false);
await ExportDeletionOrderAsync(hasCycles, cancellationToken).ConfigureAwait(false);
}
public static void GetCyclePaths_GivenTablesWithCycle_ReturnsEmptyCollection()
{
var cycleDetector = new CycleDetector();
var mockChildKey = new Mock <IDatabaseKey>();
mockChildKey.Setup(c => c.KeyType).Returns(DatabaseKeyType.Foreign);
var childKey = mockChildKey.Object;
var mockParentKey = new Mock <IDatabaseKey>();
mockParentKey.Setup(p => p.KeyType).Returns(DatabaseKeyType.Primary);
var parentKey = mockParentKey.Object;
// create tables with no cycle where the path is a -> b -> c -> a
var tableAMock = new Mock <IRelationalDatabaseTable>();
tableAMock.Setup(t => t.Name).Returns(Identifier.CreateQualifiedIdentifier("a"));
tableAMock.Setup(t => t.ParentKeys).Returns(new[]
{
new DatabaseRelationalKey(
Identifier.CreateQualifiedIdentifier("a"),
childKey,
Identifier.CreateQualifiedIdentifier("b"),
parentKey,
ReferentialAction.NoAction,
ReferentialAction.NoAction
)
});
var tableBMock = new Mock <IRelationalDatabaseTable>();
tableBMock.Setup(t => t.Name).Returns(Identifier.CreateQualifiedIdentifier("b"));
tableBMock.Setup(t => t.ParentKeys).Returns(new[]
{
new DatabaseRelationalKey(
Identifier.CreateQualifiedIdentifier("b"),
childKey,
Identifier.CreateQualifiedIdentifier("c"),
parentKey,
ReferentialAction.NoAction,
ReferentialAction.NoAction
)
});
var tableCMock = new Mock <IRelationalDatabaseTable>();
tableCMock.Setup(t => t.Name).Returns(Identifier.CreateQualifiedIdentifier("c"));
tableCMock.Setup(t => t.ParentKeys).Returns(new[]
{
new DatabaseRelationalKey(
Identifier.CreateQualifiedIdentifier("c"),
childKey,
Identifier.CreateQualifiedIdentifier("a"),
parentKey,
ReferentialAction.NoAction,
ReferentialAction.NoAction
)
});
var tables = new[]
{
tableAMock.Object,
tableBMock.Object,
tableCMock.Object
};
var result = cycleDetector.GetCyclePaths(tables);
var cycleTableNames = result.SelectMany(c => c.Select(t => t.LocalName)).ToList();
var expectedCycle = new[] { "a", "b", "c" };
Assert.Multiple(() =>
{
Assert.That(result, Has.Exactly(1).Items);
Assert.That(cycleTableNames, Has.Exactly(3).Items);
Assert.That(cycleTableNames, Is.EquivalentTo(expectedCycle));
});
}
public static void GetCyclePaths_GivenTablesWithNoCycle_ReturnsEmptyCollection()
{
var cycleDetector = new CycleDetector();
var mockChildKey = new Mock <IDatabaseKey>();
mockChildKey.Setup(c => c.KeyType).Returns(DatabaseKeyType.Foreign);
var childKey = mockChildKey.Object;
var mockParentKey = new Mock <IDatabaseKey>();
mockParentKey.Setup(p => p.KeyType).Returns(DatabaseKeyType.Primary);
var parentKey = mockParentKey.Object;
// create tables with no cycle where the path is a -> b -> c
var tableAMock = new Mock <IRelationalDatabaseTable>();
tableAMock.Setup(t => t.Name).Returns(Identifier.CreateQualifiedIdentifier("a"));
tableAMock.Setup(t => t.ParentKeys).Returns(new[]
{
new DatabaseRelationalKey(
Identifier.CreateQualifiedIdentifier("a"),
childKey,
Identifier.CreateQualifiedIdentifier("b"),
parentKey,
ReferentialAction.NoAction,
ReferentialAction.NoAction
)
});
var tableBMock = new Mock <IRelationalDatabaseTable>();
tableBMock.Setup(t => t.Name).Returns(Identifier.CreateQualifiedIdentifier("b"));
tableBMock.Setup(t => t.ParentKeys).Returns(new[]
{
new DatabaseRelationalKey(
Identifier.CreateQualifiedIdentifier("b"),
childKey,
Identifier.CreateQualifiedIdentifier("c"),
parentKey,
ReferentialAction.NoAction,
ReferentialAction.NoAction
)
});
var tableCMock = new Mock <IRelationalDatabaseTable>();
tableCMock.Setup(t => t.Name).Returns(Identifier.CreateQualifiedIdentifier("c"));
tableCMock.Setup(t => t.ParentKeys).Returns(Array.Empty <IDatabaseRelationalKey>());
var tables = new[]
{
tableAMock.Object,
tableBMock.Object,
tableCMock.Object
};
var result = cycleDetector.GetCyclePaths(tables);
Assert.That(result, Is.Empty);
}
public static void GetCyclePaths_GivenNullTables_ThrowsArgumentNullException()
{
var cycleDetector = new CycleDetector();
Assert.That(() => cycleDetector.GetCyclePaths(null), Throws.ArgumentNullException);
}
