Just.Core/Core.Tests/Base32Conversions/Decode.cs

namespace Just.Core.Tests.Base32Conversions;

public class Decode
{
    [Theory]
    [InlineData(15243, Base32EncodeOptions.None)]
    [InlineData(15243, Base32EncodeOptions.LowerCase)]
    [InlineData(15243, Base32EncodeOptions.NoPadding)]
    [InlineData(15243, Base32EncodeOptions.LowerCaseNoPadding)]
    [InlineData(812010, Base32EncodeOptions.None)]
    [InlineData(812010, Base32EncodeOptions.LowerCase)]
    [InlineData(812010, Base32EncodeOptions.NoPadding)]
    [InlineData(812010, Base32EncodeOptions.LowerCaseNoPadding)]
    [InlineData(97331334, Base32EncodeOptions.None)]
    [InlineData(97331334, Base32EncodeOptions.LowerCase)]
    [InlineData(97331334, Base32EncodeOptions.NoPadding)]
    [InlineData(97331334, Base32EncodeOptions.LowerCaseNoPadding)]
    [InlineData(20354, Base32EncodeOptions.None)]
    [InlineData(20354, Base32EncodeOptions.LowerCase)]
    [InlineData(20354, Base32EncodeOptions.NoPadding)]
    [InlineData(20354, Base32EncodeOptions.LowerCaseNoPadding)]
    [InlineData(33409, Base32EncodeOptions.None)]
    [InlineData(33409, Base32EncodeOptions.LowerCase)]
    [InlineData(33409, Base32EncodeOptions.NoPadding)]
    [InlineData(33409, Base32EncodeOptions.LowerCaseNoPadding)]
    [InlineData(59113, Base32EncodeOptions.None)]
    [InlineData(59113, Base32EncodeOptions.LowerCase)]
    [InlineData(59113, Base32EncodeOptions.NoPadding)]
    [InlineData(59113, Base32EncodeOptions.LowerCaseNoPadding)]
    public void WhenEncodedToString_ShouldBeDecodedToTheSameByteArray(int seed, Base32EncodeOptions options)
    {
        var rng = new Random(seed);

        for (int i = 1; i <= 512; i++)
        {
            var testBytes = new byte[i];
            rng.NextBytes(testBytes);

            var resultString = Base32.Encode(testBytes, options);
            var resultBytes = Base32.Decode(resultString);

            resultBytes.ShouldBeEquivalentTo(testBytes);
        }
    }

    [Theory]
    [InlineData("FG4M3ZQM3TVWDMBUP5L7N7V3JS7KBM2E", new byte[] { 0x29, 0xb8, 0xcd, 0xe6, 0x0c, 0xdc, 0xeb, 0x61, 0xb0, 0x34, 0x7f, 0x57, 0xf6, 0xfe, 0xbb, 0x4c, 0xbe, 0xa0, 0xb3, 0x44, })]
    [InlineData("fg4m3zqm3tvwdmbup5l7n7v3js7kbm2e", new byte[] { 0x29, 0xb8, 0xcd, 0xe6, 0x0c, 0xdc, 0xeb, 0x61, 0xb0, 0x34, 0x7f, 0x57, 0xf6, 0xfe, 0xbb, 0x4c, 0xbe, 0xa0, 0xb3, 0x44, })]
    [InlineData("WXYEOQUZULMCY6ZQTDOLTRUZZMKQ====", new byte[] { 0xb5, 0xf0, 0x47, 0x42, 0x99, 0xa2, 0xd8, 0x2c, 0x7b, 0x30, 0x98, 0xdc, 0xb9, 0xc6, 0x99, 0xcb, 0x15, })]
    [InlineData("wxyeoquzulmcy6zqtdoltruzzmkq====", new byte[] { 0xb5, 0xf0, 0x47, 0x42, 0x99, 0xa2, 0xd8, 0x2c, 0x7b, 0x30, 0x98, 0xdc, 0xb9, 0xc6, 0x99, 0xcb, 0x15, })]
    [InlineData("2IO2HTALCXZWCBD2", new byte[] { 0xd2, 0x1d, 0xa3, 0xcc, 0x0b, 0x15, 0xf3, 0x61, 0x04, 0x7a, })]
    [InlineData("ZFXJMF5N", new byte[] { 0b11001001, 0b01101110, 0b10010110, 0b00010111, 0b10101101, })]
    [InlineData("zfxjmf5n", new byte[] { 0b11001001, 0b01101110, 0b10010110, 0b00010111, 0b10101101, })]
    [InlineData("CPIKTMY=", new byte[] { 0b00010011, 0b11010000, 0b10101001, 0b10110011, })]
    [InlineData("EFCDEAA=", new byte[] { 0x21, 0x44, 0x32, 0x00, })]
    [InlineData("EFCDEAI=", new byte[] { 0x21, 0x44, 0x32, 0x01, })]
    [InlineData("EFCDEAQ=", new byte[] { 0x21, 0x44, 0x32, 0x02, })]
    [InlineData("EFCDEAY=", new byte[] { 0x21, 0x44, 0x32, 0x03, })]
    [InlineData("EFCDEBA=", new byte[] { 0x21, 0x44, 0x32, 0x04, })]
    [InlineData("JVNJA===", new byte[] { 0b01001101, 0b01011010, 0b10010000, })]
    [InlineData("74OQ====", new byte[] { 0b11111111, 0b00011101, })]
    public void WhenCalledWithValidString_ShouldReturnValidByteArray(string str, byte[] expected)
    {
        var actualBytesArray = Base32.Decode(str);
        actualBytesArray.ShouldBe(expected);
    }

    [Theory]
    [InlineData("ZFXJMF5N====", new byte[] { 0b11001001, 0b01101110, 0b10010110, 0b00010111, 0b10101101, })]
    [InlineData("CPIKTMY=====", new byte[] { 0b00010011, 0b11010000, 0b10101001, 0b10110011, })]
    [InlineData("JVNJA=======", new byte[] { 0b01001101, 0b01011010, 0b10010000, })]
    public void WhenCalledWithValidStringThatEndsWithPaddingSign_ShouldReturnValidByteArray(string testString, byte[] expected)
    {
        var actualBytesArray = Base32.Decode(testString);
        actualBytesArray.ShouldBe(expected);
    }

    [Theory]
    [InlineData("ZFXJMF5N", new byte[] { 0b11001001, 0b01101110, 0b10010110, 0b00010111, 0b10101101, })]
    [InlineData("CPIKTMY", new byte[] { 0b00010011, 0b11010000, 0b10101001, 0b10110011, })]
    [InlineData("JVNJA", new byte[] { 0b01001101, 0b01011010, 0b10010000, })]
    public void WhenCalledWithValidStringWithoutPaddingSign_ShouldReturnValidByteArray(string testString, byte[] expected)
    {
        var actualBytesArray = Base32.Decode(testString);
        actualBytesArray.ShouldBe(expected);
    }

    [Theory]
    [InlineData("  ")]
    [InlineData("hg2515i3215q")]
    [InlineData("hg712)21")]
    [InlineData("hg712f 211")]
    [InlineData("AEBAGB^F")]
    public void WhenCalledWithNotValidString_ShouldThrowFormatException(string testString)
    {
        Action action = () => _ = Base32.Decode(testString);
        action.ShouldThrow<FormatException>()
            .WithMessage("Provided string contains invalid characters.");
    }

    [Theory]
    [InlineData("A")]
    [InlineData("AAA")]
    [InlineData("AAAAAA")]
    [InlineData("AEBAGBAFA")]
    [InlineData("AEBAGBAFAAA")]
    [InlineData("AEBAGBAFAAAAAA")]
    public void WhenCalledWithInvalidStringLength_ShouldThrowFormatException(string testString)
    {
        Action action = () => _ = Base32.Decode(testString);
        action.ShouldThrow<FormatException>()
            .WithMessage("Invalid Base32 string length.");
    }

    [Theory]
    [InlineData("ABCDEFG")]
    [InlineData("AAAAAAB")]
    [InlineData("EFCDF5J")]
    [InlineData("EFCDF5P")]
    public void WhenCalledWithInvalidLastByteEncoding_ShouldThrowFormatException(string testString)
    {
        Action action = () => _ = Base32.Decode(testString);
        action.ShouldThrow<FormatException>()
            .WithMessage("Invalid Base32 string. Inconsistent tail bits.");
    }

    [Theory]
    [InlineData(null)]
    [InlineData("")]
    public void WhenCalledWithNullString_ShouldReturnEmptyArray(string? testString)
    {
        Base32.Decode(testString).ShouldBeEmpty();
    }

    [Theory]
    [InlineData("====")]
    [InlineData("============")]
    public void WhenCalledWithOnlyPadding_ShouldReturnEmptyArray(string testString)
    {
        Base32.Decode(testString).ShouldBeEmpty();
    }

    [Theory]
    [InlineData("AEBAGBAF", 1)]
    [InlineData("AEBAGBAF", 2)]
    [InlineData("AEBAGBAF", 3)]
    [InlineData("AEBAGBAFAY", 5)]
    [InlineData("AEBAGBAFAYDQ", 6)]
    public void SpanTooSmall_ThrowsArgumentException(string input, int outputLength)
    {
        byte[] output = new byte[outputLength];
        Action action = () => _ = Base32.Decode(input, output);
        action.ShouldThrow<ArgumentException>()
            .WithMessage("Decoded input can not fit in output span. (Parameter 'output')");
    }
}