sql-utilities/tests/Strata.SqlTools.SqlBreakdown.Tests/ExpressionTests/DateFunctionTests.cs

using Strata.SqlTools.SqlBreakdown.Classes;
using Strata.SqlTools.SqlBreakdown.Expressions;

namespace Strata.SqlTools.SqlBreakdown.Tests.ExpressionTests;

[TestFixture]
public class DateFunctionTests : ExpressionTestsBase
{
    private static IEnumerable<TestCaseData> DateFunctionTestCases()
    {
        var testCases = new[]
        {
            new ExpressionTestCase
            {
                Name = "GetFiscalYearMonthExpression_{m}",
                Arrange = new Dictionary<string, Expression>
                {
                    ["dischargeDate"] = new RegisteredTableColumnExpression(4, "DISCHARGE_DATE", new RegisteredTableSource(101, "CLIENT_DSS", "DEPT", "PES"))
                },
                Act = (columns, visitor) =>
                {
                    var dischargeDate = columns["dischargeDate"];
                    var fiscal = TestExpressionFactory.GetFiscalYearMonthExpression(dischargeDate, 7, 1);
                    return fiscal.Accept(visitor);
                },
                Assertions = result =>
                {
                    var sql = (string)result;
                    Assert.That(sql, Is.Not.Null);
                    Assert.That(sql, Is.Not.Empty);
                    Assert.That(sql, Is.EqualTo("DATE_TRUNC('month', DATEADD('month', 6, PES.DISCHARGE_DATE))"));
                    return true;
                }
            }
        };

        foreach (var testCase in testCases)
        {
            yield return new TestCaseData(testCase).SetName(testCase.Name);
        }
    }

    [TestCaseSource(nameof(DateFunctionTestCases))]
    public void DateFunction_GeneratesCorrectSql(ExpressionTestCase testCase)
        => ExecuteExpressionTest(testCase);
}