/// <summary>
/// If (a) <paramref name="expression"/> is of type `bool` and (b) it is `false`, attempts to return a string representation of *why* it is `false`.
/// Otherwise, behaves the same as <see cref="GetFullString"/>.
/// <paramref name="expression"/> must be compilable without arguments.
/// </summary>
public static (string ExpressionString, IReadOnlyCollection <(string Name, object Value)> DebugValues) GetDiagnosticString(Expression expression)
{
var vistor = new DebugValueExpressionVisitor();
vistor.VisitDiagnosticRoot(expression);
return(vistor.ToString(), vistor.DebugValues);
}
/// <summary>
/// Starts a chain of assertions on <paramref name="value"/>.
/// Asserts that <paramref name="value"/> is not `null`.
/// </summary>
public static Assertable <T> HasValue <T>(T value, string name = null)
where T : class
{
var parameter = DebugValueExpressionVisitor.GetDebugExpresssion(name ?? "value", value);
if (value == null)
{
TestFrameworkProvider.Fail(GetDiagnosticMessage(Expression.NotEqual(parameter, Expression.Constant(null, typeof(T))), null, s_emptyContext));
return(Assertable <T> .NoOp());
}
return(Assertable <T> .FromValueExpression(value, parameter));
}
