sql-utilities/tests/Strata.SqlTools.PostgreSql.Tests/PostgreSql/CommandVisitorTests.cs

using Strata.SqlTools.Visitors.PostgreSql;

namespace Strata.SqlTools.PostgreSql.Tests.PostgreSql;

[TestFixture]
public class CommandVisitorTests
{
    [Test]
    public void TwoVisitors_HaveIndependentParameterIndices()
    {
        var visitor1 = new CommandVisitor();
        var visitor2 = new CommandVisitor();

        var param1a = InvokeFormatParameterName(visitor1, "p");
        var param1b = InvokeFormatParameterName(visitor1, "p");
        var param2a = InvokeFormatParameterName(visitor2, "p");

        Assert.That(param1a, Is.EqualTo("$1"), "first visitor's first parameter should be $1");
        Assert.That(param1b, Is.EqualTo("$2"), "first visitor's second parameter should be $2");
        Assert.That(param2a, Is.EqualTo("$1"), "second visitor must start at $1, not inherit visitor1's counter");
    }

    private static string InvokeFormatParameterName(CommandVisitor visitor, string name)
    {
        var method = typeof(CommandVisitor).GetMethod(
            "FormatParameterName",
            System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Public)
            ?? typeof(Strata.SqlTools.Visitors.SqlServer.CommandVisitor).GetMethod(
                "FormatParameterName",
                System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
        Assert.That(method, Is.Not.Null, "FormatParameterName must exist as a protected method on the visitor hierarchy");
        return (string)method!.Invoke(visitor, new object[] { name })!;
    }
}