public void Ctor_checks_else_result_type()
{
var ex = Assert.Throws <ArgumentException>(
() => new CaseExpression(
new[] { new CaseWhenClause(Expression.Constant(false), Expression.Constant(false)) },
Expression.Constant(0)));
Assert.Contains(
RelationalStrings.CaseElseResultTypeUnexpected(typeof(int), typeof(bool)),
ex.Message);
Assert.Equal("elseResult", ex.ParamName);
}
/// <summary>
/// Initializes a new instance of the <see cref="CaseExpression" /> class.
/// </summary>
/// <param name="operand"> The case operand expression. </param>
/// <param name="whenClauses"> The list of when clauses. </param>
/// <param name="elseResult"> The else result expression. </param>
public CaseExpression(
[CanBeNull] Expression operand,
[NotNull] IReadOnlyList <CaseWhenClause> whenClauses,
[CanBeNull] Expression elseResult)
{
Check.NotEmpty(whenClauses, nameof(whenClauses));
var resultType = whenClauses[0].Result.Type;
var expectedWhenOperandType = operand?.Type ?? typeof(bool);
foreach (var whenClause in whenClauses)
{
if (operand != null &&
whenClause.Test.Type != expectedWhenOperandType)
{
throw new ArgumentException(
RelationalStrings.CaseWhenClauseTestTypeUnexpected(
whenClause.Test.Type,
expectedWhenOperandType),
nameof(whenClauses));
}
if (whenClause.Result.Type != resultType)
{
throw new ArgumentException(
RelationalStrings.CaseWhenClauseResultTypeUnexpected(whenClause.Result.Type, resultType),
nameof(whenClauses));
}
}
if (elseResult != null &&
elseResult.Type != resultType)
{
throw new ArgumentException(
RelationalStrings.CaseElseResultTypeUnexpected(elseResult.Type, resultType),
nameof(elseResult));
}
Type = resultType;
Operand = operand;
ElseResult = elseResult;
WhenClauses = whenClauses;
}