basic-computer-games/00_Common/dotnet/Games.Common.Test/IO/TokenReaderTests.cs

using System;
using System.IO;
using System.Linq;
using FluentAssertions;
using FluentAssertions.Execution;
using Xunit;

using static System.Environment;
using static Games.Common.IO.Strings;

namespace Games.Common.IO
{
    public class TokenReaderTests
    {
        private readonly StringWriter _outputWriter;

        public TokenReaderTests()
        {
            _outputWriter = new StringWriter();
        }

        [Fact]
        public void ReadTokens_QuantityNeededZero_ThrowsArgumentException()
        {
            var sut = TokenReader.ForStrings(new TextIO(new StringReader(""), _outputWriter));

            Action readTokens = () => sut.ReadTokens("", 0);

            readTokens.Should().Throw<ArgumentOutOfRangeException>()
                .WithMessage("'quantityNeeded' must be greater than zero.*")
                .WithParameterName("quantityNeeded");
        }


        [Theory]
        [MemberData(nameof(ReadTokensTestCases))]
        public void ReadTokens_ReadingValuesHasExpectedPromptsAndResults(
            string prompt,
            uint tokenCount,
            string input,
            string expectedOutput,
            string[] expectedResult)
        {
            var sut = TokenReader.ForStrings(new TextIO(new StringReader(input + NewLine), _outputWriter));

            var result = sut.ReadTokens(prompt, tokenCount);
            var output = _outputWriter.ToString();

            using var _ = new AssertionScope();
            output.Should().Be(expectedOutput);
            result.Select(t => t.String).Should().BeEquivalentTo(expectedResult);
        }

        [Theory]
        [MemberData(nameof(ReadNumericTokensTestCases))]
        public void ReadTokens_Numeric_ReadingValuesHasExpectedPromptsAndResults(
            string prompt,
            uint tokenCount,
            string input,
            string expectedOutput,
            float[] expectedResult)
        {
            var sut = TokenReader.ForNumbers(new TextIO(new StringReader(input + NewLine), _outputWriter));

            var result = sut.ReadTokens(prompt, tokenCount);
            var output = _outputWriter.ToString();

            using var _ = new AssertionScope();
            output.Should().Be(expectedOutput);
            result.Select(t => t.Number).Should().BeEquivalentTo(expectedResult);
        }

        public static TheoryData<string, uint, string, string, string[]> ReadTokensTestCases()
        {
            return new()
            {
                { "Name", 1, "Bill", "Name? ", new[] { "Bill" } },
                { "Names", 2, " Bill , Bloggs ", "Names? ", new[] { "Bill", "Bloggs" } },
                { "Names", 2, $" Bill{NewLine}Bloggs ", "Names? ?? ", new[] { "Bill", "Bloggs" } },
                {
                    "Foo",
                    6,
                    $"1,2{NewLine}\" a,b \"{NewLine},\"\"c,d{NewLine}d\"x,e,f",
                    $"Foo? ?? ?? ?? {ExtraInput}{NewLine}",
                    new[] { "1", "2", " a,b ", "", "", "d\"x" }
                }
            };
        }

        public static TheoryData<string, uint, string, string, float[]> ReadNumericTokensTestCases()
        {
            return new()
            {
                { "Age", 1, "23", "Age? ", new[] { 23F } },
                { "Constants", 2, " 3.141 , 2.71 ", "Constants? ", new[] { 3.141F, 2.71F } },
                { "Answer", 1, $"Forty-two{NewLine}42 ", $"Answer? {NumberExpected}{NewLine}? ", new[] { 42F } },
                {
                    "Foo",
                    6,
                    $"1,2{NewLine}\" a,b \"{NewLine}3, 4  {NewLine}5.6,7,a, b",
                    $"Foo? ?? {NumberExpected}{NewLine}? ?? {ExtraInput}{NewLine}",
                    new[] { 1, 2, 3, 4, 5.6F, 7 }
                }
            };
        }
    }
}