src/Tests/OneScript.StandardLibrary.Tests/FileBackingStreamTest.cs - develop - EvilBeaver/OneScript

src/Tests/OneScript.StandardLibrary.Tests/FileBackingStreamTest.cs
220 строк7 KB
Andrei Ovsiankin
Некоторая адаптация под нет8 в части указания фреймворка
17 июн 2025, 17:29
17 июн 2025, 17:296d8e2cb
/*----------------------------------------------------------
This Source Code Form is subject to the terms of the
Mozilla Public License, v.2.0. If a copy of the MPL
was not distributed with this file, You can obtain one
at http://mozilla.org/MPL/2.0/.
----------------------------------------------------------*/

using System;
using System.Collections.Generic;
using System.IO;
using Xunit;
using FluentAssertions;
using OneScript.StandardLibrary.Binary;

namespace OneScript.StandardLibrary.Tests
{
    public class FileBackingStreamTest
    {
        [Fact]
        public void CanDoBasicReadWithMemory()
        {
            using var stream = new FileBackingStream(10);
            stream.Write(new byte[] { 1, 2, 3, 4, 5 });

            stream.Position = 0;
            stream.Position.Should().Be(0);
            stream.HasBackingFile.Should().BeFalse();
            stream.Length.Should().Be(5);

            var dest = new byte[5];
            var size = stream.Read(dest, 0, 5);
            size.Should().Be(5);
            dest.Should().Equal(1, 2, 3, 4, 5);
        }

        [Fact]
        public void CanDoBasicReadWithFile()
        {
            using var stream = new FileBackingStream(10);
            stream.SwitchToFile();
            stream.Write(new byte[] { 1, 2, 3, 4, 5 });

            stream.Position = 0;
            stream.Position.Should().Be(0);
            stream.HasBackingFile.Should().BeTrue();
            stream.Length.Should().Be(5);

            var dest = new byte[5];
            var size = stream.Read(dest, 0, 5);
            size.Should().Be(5);
            dest.Should().Equal(1, 2, 3, 4, 5);
        }

        [Fact]
        public void GrowsOnWriteToEnd()
        {
            using var stream = new FileBackingStream(5);
            stream.Write(new byte[] { 1, 2, 3, 4, 5 });
            stream.HasBackingFile.Should().BeFalse();
            stream.Position.Should().Be(5);

            stream.Write(new byte[] { 1, 2, 3, 4, 5 });
            stream.HasBackingFile.Should().BeTrue();
            stream.Position.Should().Be(10);
            stream.Length.Should().Be(10);

            EnsureContent(stream, new byte[] { 1, 2, 3, 4, 5, 1, 2, 3, 4, 5 });
        }

        [Fact]
        public void GrowsOnWriteToMiddle()
        {
            using var stream = new FileBackingStream(5);
            stream.Write(new byte[] { 1, 2, 3, 4, 5 });
            stream.Position = 2;
            stream.HasBackingFile.Should().BeFalse();

            stream.Write(new byte[] { 6, 6, 6, 6, 6 });
            stream.HasBackingFile.Should().BeTrue();
            stream.Position.Should().Be(7);
            stream.Length.Should().Be(7);

            EnsureContent(stream, new byte[] { 1, 2, 6, 6, 6, 6, 6 });
        }

        [Fact]
        public void GrowsOnWriteToStart()
        {
            using var stream = new FileBackingStream(5);
            stream.Write(new byte[] { 1, 2, 3, 4, 5 });
            stream.Position = 0;
            stream.HasBackingFile.Should().BeFalse();

            stream.Write(new byte[] { 7, 6, 5, 4, 3, 2, 1 });
            stream.HasBackingFile.Should().BeTrue();
            stream.Position.Should().Be(7);
            stream.Length.Should().Be(7);

            EnsureContent(stream, new byte[] { 7, 6, 5, 4, 3, 2, 1 });
        }

        [Fact]
        public void DoesNotGrowOnWriteInsideLimit()
        {
            using var stream = new FileBackingStream(5);
            stream.Write(new byte[] { 1, 2, 3, 4, 5 });
            stream.Position = 2;
            stream.HasBackingFile.Should().BeFalse();

            stream.Write(new byte[] { 0, 0, 0 });
            stream.HasBackingFile.Should().BeFalse();
            stream.Position.Should().Be(5);
            stream.Length.Should().Be(5);

            EnsureContent(stream, new byte[] { 1, 2, 0, 0, 0 });
        }

        [Fact]
        public void CanCropIntoMemoryAgain()
        {
            using var stream = new FileBackingStream(5);
            stream.Write(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 });
            stream.HasBackingFile.Should().BeTrue();
            stream.Length.Should().Be(10);
            stream.SetLength(5);
            stream.HasBackingFile.Should().BeFalse();

            EnsureContent(stream, new byte[] { 1, 2, 3, 4, 5 });
        }

        [Fact]
        public void SettingLengthBeyondLimitSwitchesToFile()
        {
            using var stream = new FileBackingStream(5);
            stream.HasBackingFile.Should().BeFalse();
            stream.SetLength(15);
            stream.HasBackingFile.Should().BeTrue();
        }

        [Fact]
        public void ThrowsWhenCantSwitchIntoMemory()
        {
            using var stream = new FileBackingStream(5);
            stream.Write(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 });
            stream.HasBackingFile.Should().BeTrue();

            Assert.Throws<InvalidOperationException>(() => stream.SwitchToMemory());
        }

        [Fact]
        public void SetPositionBeyondLength()
        {
            using var stream = new FileBackingStream(5);
            stream.Position = 10;

            stream.Length.Should().Be(0);
            stream.HasBackingFile.Should().BeFalse();

            stream.Write(new byte[] { 1, 2, 3 });
            stream.Position.Should().Be(13);
            stream.Length.Should().Be(13);
            stream.HasBackingFile.Should().BeTrue();
        }

        [Fact]
        public void TempFileGetsDeletedOnClose()
        {
            using var stream = new FileBackingStream(5);
            stream.Write(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 });
            stream.HasBackingFile.Should().BeTrue();
            var tempFile = stream.FileName;

            stream.SetLength(4);
            stream.HasBackingFile.Should().BeFalse();
            File.Exists(tempFile).Should().BeFalse();
        }

        private void EnsureContent(Stream stream, IEnumerable<byte> expected)
        {
            stream.Position = 0;
            var actual = new byte[stream.Length];
            stream.Read(actual).Should().Be((int)stream.Length);

            actual.Should().Equal(expected);
        }

        [Fact(Skip = "Platform test")]
        public void SetPositionBeyondMemoryStream()
        {
            using var ms = new MemoryStream();
            ms.Position = 10;

            ms.Length.Should().Be(0);
            ms.Write(new byte[] { 1, 2, 3 });
            ms.Position.Should().Be(13);
            ms.Length.Should().Be(13);
        }

        [Fact(Skip = "Platform test")]
        public void SetPositionBeyondFileStream()
        {
            var path = Path.GetTempFileName();
            var fs = new FileStream(path, FileMode.Create);
            try
            {
                fs.Position = 10;

                fs.Length.Should().Be(0);
                fs.Write(new byte[] { 1, 2, 3 });
                fs.Position.Should().Be(13);
                fs.Length.Should().Be(13);
            }
            finally
            {
                fs.Close();
                File.Delete(path);
            }
        }
    }
}