feat: implement GetTempFileName for simulated Path (#570)

vbreuss · web-flow · commit 6d984e25c45a · 2024-04-20T21:58:54.000Z
Implement the `GetTempFileName` methods for `Path` and allow initialization with `IRandomProvider` to test random edge cases.
diff --git a/Source/Testably.Abstractions.Testing/Helpers/Execute.MacPath.cs b/Source/Testably.Abstractions.Testing/Helpers/Execute.MacPath.cs
@@ -4,12 +4,14 @@ internal partial class Execute
 {
 	private sealed class MacPath(MockFileSystem fileSystem) : LinuxPath(fileSystem)
 	{
+		private readonly MockFileSystem _fileSystem = fileSystem;
 		private string? _tempPath;
 
 		/// <inheritdoc cref="IPath.GetTempPath()" />
 		public override string GetTempPath()
 		{
-			_tempPath ??= $"/var/folders/{RandomString(2)}/{RandomString(2)}_{RandomString(27)}/T/";
+			_tempPath ??=
+				$"/var/folders/{RandomString(_fileSystem, 2)}/{RandomString(_fileSystem, 2)}_{RandomString(_fileSystem, 27)}/T/";
 			return _tempPath;
 		}
 	}
diff --git a/Source/Testably.Abstractions.Testing/Helpers/Execute.NativePath.cs b/Source/Testably.Abstractions.Testing/Helpers/Execute.NativePath.cs
@@ -198,7 +198,7 @@ public string GetRelativePath(string relativeTo, string path)
 			"Insecure temporary file creation methods should not be used. Use `Path.Combine(Path.GetTempPath(), Path.GetRandomFileName())` instead.")]
 #endif
 		public string GetTempFileName()
-			=> System.IO.Path.GetTempFileName();
+			=> CreateTempFileName(fileSystem);
 
 		/// <inheritdoc cref="Path.GetTempPath()" />
 		public string GetTempPath()
diff --git a/Source/Testably.Abstractions.Testing/Helpers/Execute.SimulatedPath.cs b/Source/Testably.Abstractions.Testing/Helpers/Execute.SimulatedPath.cs
@@ -1,7 +1,6 @@
 ﻿using System;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
-using System.Linq;
 using System.Text;
 #if FEATURE_FILESYSTEM_NET7
 using Testably.Abstractions.Testing.Storage;
@@ -284,7 +283,7 @@ public ReadOnlySpan<char> GetPathRoot(ReadOnlySpan<char> path)
 
 		/// <inheritdoc cref="IPath.GetRandomFileName()" />
 		public string GetRandomFileName()
-			=> $"{RandomString(8)}.{RandomString(3)}";
+			=> $"{RandomString(fileSystem, 8)}.{RandomString(fileSystem, 3)}";
 
 #if FEATURE_PATH_RELATIVE
 		/// <inheritdoc cref="IPath.GetRelativePath(string, string)" />
@@ -306,7 +305,7 @@ public string GetRelativePath(string relativeTo, string path)
 			"Insecure temporary file creation methods should not be used. Use `Path.Combine(Path.GetTempPath(), Path.GetRandomFileName())` instead.")]
 #endif
 		public string GetTempFileName()
-			=> System.IO.Path.GetTempFileName();
+			=> CreateTempFileName(fileSystem);
 
 		/// <inheritdoc cref="IPath.GetTempPath()" />
 		public abstract string GetTempPath();
@@ -573,13 +572,6 @@ private string JoinInternal(string?[] paths)
 
 		protected abstract string NormalizeDirectorySeparators(string path);
 
-		protected string RandomString(int length)
-		{
-			const string chars = "abcdefghijklmnopqrstuvwxyz0123456789";
-			return new string(Enumerable.Repeat(chars, length)
-				.Select(s => s[fileSystem.RandomSystem.Random.Shared.Next(s.Length)]).ToArray());
-		}
-
 		/// <summary>
 		///     Remove relative segments from the given path (without combining with a root).
 		/// </summary>
diff --git a/Source/Testably.Abstractions.Testing/Helpers/Execute.cs b/Source/Testably.Abstractions.Testing/Helpers/Execute.cs
@@ -1,4 +1,6 @@
 ﻿using System;
+using System.IO;
+using System.Linq;
 using System.Runtime.InteropServices;
 
 namespace Testably.Abstractions.Testing.Helpers;
@@ -78,4 +80,32 @@ internal Execute(MockFileSystem fileSystem)
 			: StringComparison.OrdinalIgnoreCase;
 		Path = new NativePath(fileSystem);
 	}
+
+	internal static string CreateTempFileName(MockFileSystem fileSystem)
+	{
+		int i = 0;
+		string tempPath = fileSystem.Path.GetTempPath();
+		fileSystem.Directory.CreateDirectory(tempPath);
+		while (true)
+		{
+			string fileName = $"{RandomString(fileSystem, 8)}.tmp";
+			string path = string.Concat(tempPath, fileName);
+			try
+			{
+				fileSystem.File.Open(path, FileMode.CreateNew, FileAccess.Write).Dispose();
+				return path;
+			}
+			catch (IOException) when (i < 100)
+			{
+				i++; // Don't let unforeseen circumstances cause us to loop forever
+			}
+		}
+	}
+
+	internal static string RandomString(MockFileSystem fileSystem, int length)
+	{
+		const string chars = "abcdefghijklmnopqrstuvwxyz0123456789";
+		return new string(Enumerable.Repeat(chars, length)
+			.Select(s => s[fileSystem.RandomSystem.Random.Shared.Next(s.Length)]).ToArray());
+	}
 }
diff --git a/Source/Testably.Abstractions.Testing/MockFileSystem.cs b/Source/Testably.Abstractions.Testing/MockFileSystem.cs
@@ -4,6 +4,7 @@
 using System.IO;
 using Testably.Abstractions.Testing.FileSystem;
 using Testably.Abstractions.Testing.Helpers;
+using Testably.Abstractions.Testing.RandomSystem;
 using Testably.Abstractions.Testing.Statistics;
 using Testably.Abstractions.Testing.Storage;
 
@@ -107,7 +108,7 @@ internal MockFileSystem(Action<Initialization> initializationCallback)
 			: new Execute(this, SimulationMode);
 		StatisticsRegistration = new FileSystemStatistics(this);
 		using IDisposable release = StatisticsRegistration.Ignore();
-		RandomSystem = new MockRandomSystem();
+		RandomSystem = new MockRandomSystem(initialization.RandomProvider ?? RandomProvider.Default());
 		TimeSystem = new MockTimeSystem(TimeProvider.Now());
 		_pathMock = new PathMock(this);
 		_storage = new InMemoryStorage(this);
@@ -231,6 +232,11 @@ internal class Initialization
 		/// </summary>
 		internal string? CurrentDirectory { get; private set; }
 
+		/// <summary>
+		///     The <see cref="IRandomProvider" /> for the <see cref="RandomSystem" />.
+		/// </summary>
+		internal IRandomProvider? RandomProvider { get; private set; }
+
 		/// <summary>
 		///     The simulated operating system.
 		/// </summary>
@@ -262,5 +268,14 @@ internal Initialization UseCurrentDirectory()
 			CurrentDirectory = System.IO.Directory.GetCurrentDirectory();
 			return this;
 		}
+
+		/// <summary>
+		///     Use the given <paramref name="randomProvider" /> for the <see cref="RandomSystem" />.
+		/// </summary>
+		internal Initialization UseRandomProvider(IRandomProvider randomProvider)
+		{
+			RandomProvider = randomProvider;
+			return this;
+		}
 	}
 }
diff --git a/Source/Testably.Abstractions.Testing/MockRandomSystem.cs b/Source/Testably.Abstractions.Testing/MockRandomSystem.cs
@@ -26,11 +26,11 @@ public MockRandomSystem() : this(Testing.RandomProvider.Default())
 	}
 
 	/// <summary>
-	///     Initializes the <see cref="MockRandomSystem" /> with the specified <paramref name="randomProviderProvider" />.
+	///     Initializes the <see cref="MockRandomSystem" /> with the specified <paramref name="randomProvider" />.
 	/// </summary>
-	public MockRandomSystem(IRandomProvider randomProviderProvider)
+	public MockRandomSystem(IRandomProvider randomProvider)
 	{
-		RandomProvider = randomProviderProvider;
+		RandomProvider = randomProvider;
 		_guidMock = new GuidMock(this);
 		_randomFactoryMock = new RandomFactoryMock(this);
 	}
diff --git a/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_net6.0.txt b/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_net6.0.txt
@@ -122,7 +122,7 @@ namespace Testably.Abstractions.Testing
     public sealed class MockRandomSystem : Testably.Abstractions.IRandomSystem
     {
         public MockRandomSystem() { }
-        public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProviderProvider) { }
+        public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProvider) { }
         public Testably.Abstractions.RandomSystem.IGuid Guid { get; }
         public Testably.Abstractions.RandomSystem.IRandomFactory Random { get; }
         public Testably.Abstractions.Testing.RandomSystem.IRandomProvider RandomProvider { get; }
diff --git a/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_net7.0.txt b/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_net7.0.txt
@@ -122,7 +122,7 @@ namespace Testably.Abstractions.Testing
     public sealed class MockRandomSystem : Testably.Abstractions.IRandomSystem
     {
         public MockRandomSystem() { }
-        public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProviderProvider) { }
+        public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProvider) { }
         public Testably.Abstractions.RandomSystem.IGuid Guid { get; }
         public Testably.Abstractions.RandomSystem.IRandomFactory Random { get; }
         public Testably.Abstractions.Testing.RandomSystem.IRandomProvider RandomProvider { get; }
diff --git a/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_net8.0.txt b/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_net8.0.txt
@@ -122,7 +122,7 @@ namespace Testably.Abstractions.Testing
     public sealed class MockRandomSystem : Testably.Abstractions.IRandomSystem
     {
         public MockRandomSystem() { }
-        public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProviderProvider) { }
+        public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProvider) { }
         public Testably.Abstractions.RandomSystem.IGuid Guid { get; }
         public Testably.Abstractions.RandomSystem.IRandomFactory Random { get; }
         public Testably.Abstractions.Testing.RandomSystem.IRandomProvider RandomProvider { get; }
diff --git a/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_netstandard2.0.txt b/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_netstandard2.0.txt
@@ -120,7 +120,7 @@ namespace Testably.Abstractions.Testing
     public sealed class MockRandomSystem : Testably.Abstractions.IRandomSystem
     {
         public MockRandomSystem() { }
-        public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProviderProvider) { }
+        public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProvider) { }
         public Testably.Abstractions.RandomSystem.IGuid Guid { get; }
         public Testably.Abstractions.RandomSystem.IRandomFactory Random { get; }
         public Testably.Abstractions.Testing.RandomSystem.IRandomProvider RandomProvider { get; }
diff --git a/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_netstandard2.1.txt b/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_netstandard2.1.txt
@@ -120,7 +120,7 @@ namespace Testably.Abstractions.Testing
     public sealed class MockRandomSystem : Testably.Abstractions.IRandomSystem
     {
         public MockRandomSystem() { }
-        public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProviderProvider) { }
+        public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProvider) { }
         public Testably.Abstractions.RandomSystem.IGuid Guid { get; }
         public Testably.Abstractions.RandomSystem.IRandomFactory Random { get; }
         public Testably.Abstractions.Testing.RandomSystem.IRandomProvider RandomProvider { get; }
diff --git a/Tests/Helpers/Testably.Abstractions.Tests.SourceGenerator/ClassGenerators/FileSystemClassGenerator.cs b/Tests/Helpers/Testably.Abstractions.Tests.SourceGenerator/ClassGenerators/FileSystemClassGenerator.cs
@@ -272,6 +272,7 @@ private bool IncludeSimulatedTests(ClassModel @class)
 			"GetFullPathTests",
 			"GetPathRootTests",
 			"GetRandomFileNameTests",
+			"GetTempFileNameTests",
 			"GetTempPathTests",
 			"HasExtensionTests",
 			"IsPathRootedTests",
diff --git a/Tests/Testably.Abstractions.Testing.Tests/FileSystem/PathMockTests.cs b/Tests/Testably.Abstractions.Testing.Tests/FileSystem/PathMockTests.cs
@@ -0,0 +1,29 @@
+﻿using System.IO;
+
+namespace Testably.Abstractions.Testing.Tests.FileSystem;
+
+public sealed class PathMockTests
+{
+	[Theory]
+	[InlineAutoData(SimulationMode.Native)]
+	[InlineAutoData(SimulationMode.Linux)]
+	[InlineAutoData(SimulationMode.MacOS)]
+	[InlineAutoData(SimulationMode.Windows)]
+	public void GetTempFileName_WithCollisions_ShouldThrowIOException(
+		SimulationMode simulationMode, int fixedRandomValue)
+	{
+		MockFileSystem fileSystem = new(i => i
+			.SimulatingOperatingSystem(simulationMode)
+			.UseRandomProvider(RandomProvider.Generate(
+				intGenerator: new RandomProvider.Generator<int>(() => fixedRandomValue))));
+		string result = fileSystem.Path.GetTempFileName();
+
+		Exception? exception = Record.Exception(() =>
+		{
+			_ = fileSystem.Path.GetTempFileName();
+		});
+
+		exception.Should().BeOfType<IOException>();
+		fileSystem.File.Exists(result).Should().BeTrue();
+	}
+}
diff --git a/Tests/Testably.Abstractions.Testing.Tests/MockFileSystemInitializationTests.cs b/Tests/Testably.Abstractions.Testing.Tests/MockFileSystemInitializationTests.cs
@@ -1,4 +1,6 @@
-﻿using System.IO;
+﻿using System.Collections.Generic;
+using System.IO;
+using System.Linq;
 using Testably.Abstractions.Testing.Tests.TestHelpers;
 #if NET6_0_OR_GREATER
 #endif
@@ -124,6 +126,22 @@ public void UseCurrentDirectory_WithPath_ShouldUsePathCurrentDirectory(string pa
 		sut.CurrentDirectory.Should().Be(path);
 	}
 
+	[Theory]
+	[AutoData]
+	public void UseRandomProvider_ShouldUseFixedRandomValue(int fixedRandomValue)
+	{
+		MockFileSystem fileSystem = new(i => i
+			.UseRandomProvider(RandomProvider.Generate(
+				intGenerator: new RandomProvider.Generator<int>(() => fixedRandomValue))));
+
+		List<int> results = Enumerable.Range(1, 100)
+			.Select(_ => fileSystem.RandomSystem.Random.New().Next())
+			.ToList();
+		results.Add(fileSystem.RandomSystem.Random.Shared.Next());
+
+		results.Should().AllBeEquivalentTo(fixedRandomValue);
+	}
+
 	#region Helpers
 
 	public static TheoryData<SimulationMode> ValidOperatingSystems()
diff --git a/Tests/Testably.Abstractions.Tests/FileSystem/Path/GetTempFileNameTests.cs b/Tests/Testably.Abstractions.Tests/FileSystem/Path/GetTempFileNameTests.cs
@@ -0,0 +1,25 @@
+namespace Testably.Abstractions.Tests.FileSystem.Path;
+
+// ReSharper disable once PartialTypeWithSinglePart
+public abstract partial class GetTempFileNameTests<TFileSystem>
+	: FileSystemTestBase<TFileSystem>
+	where TFileSystem : IFileSystem
+{
+	[SkippableFact]
+	public void GetTempFileName_ShouldBeInTempPath()
+	{
+		string tempPath = FileSystem.Path.GetTempPath();
+
+		string result = FileSystem.Path.GetTempFileName();
+
+		result.Should().StartWith(tempPath);
+	}
+
+	[SkippableFact]
+	public void GetTempFileName_ShouldExist()
+	{
+		string result = FileSystem.Path.GetTempFileName();
+
+		FileSystem.File.Exists(result).Should().BeTrue();
+	}
+}

Original file line number	Diff line number	Diff line change
`@@ -4,12 +4,14 @@ internal partial class Execute`
`4`	`4`	`{`
`5`	`5`	`private sealed class MacPath(MockFileSystem fileSystem) : LinuxPath(fileSystem)`
`6`	`6`	`{`
	`7`	`+ private readonly MockFileSystem _fileSystem = fileSystem;`
`7`	`8`	`private string? _tempPath;`
`8`	`9`
`9`	`10`	`/// <inheritdoc cref="IPath.GetTempPath()" />`
`10`	`11`	`public override string GetTempPath()`
`11`	`12`	`{`
`12`		`- _tempPath ??= $"/var/folders/{RandomString(2)}/{RandomString(2)}_{RandomString(27)}/T/";`
	`13`	`+ _tempPath ??=`
	`14`	`+ $"/var/folders/{RandomString(_fileSystem, 2)}/{RandomString(_fileSystem, 2)}_{RandomString(_fileSystem, 27)}/T/";`
`13`	`15`	`return _tempPath;`
`14`	`16`	`}`
`15`	`17`	`}`
Original file line number	Diff line number	Diff line change
`@@ -26,11 +26,11 @@ public MockRandomSystem() : this(Testing.RandomProvider.Default())`
`26`	`26`	`}`
`27`	`27`
`28`	`28`	`/// <summary>`
`29`		`- /// Initializes the <see cref="MockRandomSystem" /> with the specified <paramref name="randomProviderProvider" />.`
	`29`	`+ /// Initializes the <see cref="MockRandomSystem" /> with the specified <paramref name="randomProvider" />.`
`30`	`30`	`/// </summary>`
`31`		`- public MockRandomSystem(IRandomProvider randomProviderProvider)`
	`31`	`+ public MockRandomSystem(IRandomProvider randomProvider)`
`32`	`32`	`{`
`33`		`- RandomProvider = randomProviderProvider;`
	`33`	`+ RandomProvider = randomProvider;`
`34`	`34`	`_guidMock = new GuidMock(this);`
`35`	`35`	`_randomFactoryMock = new RandomFactoryMock(this);`
`36`	`36`	`}`
Original file line number	Diff line number	Diff line change
`@@ -122,7 +122,7 @@ namespace Testably.Abstractions.Testing`
`122`	`122`	`public sealed class MockRandomSystem : Testably.Abstractions.IRandomSystem`
`123`	`123`	`{`
`124`	`124`	`public MockRandomSystem() { }`
`125`		`- public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProviderProvider) { }`
	`125`	`+ public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProvider) { }`
`126`	`126`	`public Testably.Abstractions.RandomSystem.IGuid Guid { get; }`
`127`	`127`	`public Testably.Abstractions.RandomSystem.IRandomFactory Random { get; }`
`128`	`128`	`public Testably.Abstractions.Testing.RandomSystem.IRandomProvider RandomProvider { get; }`
Original file line number	Diff line number	Diff line change
`@@ -120,7 +120,7 @@ namespace Testably.Abstractions.Testing`
`120`	`120`	`public sealed class MockRandomSystem : Testably.Abstractions.IRandomSystem`
`121`	`121`	`{`
`122`	`122`	`public MockRandomSystem() { }`
`123`		`- public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProviderProvider) { }`
	`123`	`+ public MockRandomSystem(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProvider) { }`
`124`	`124`	`public Testably.Abstractions.RandomSystem.IGuid Guid { get; }`
`125`	`125`	`public Testably.Abstractions.RandomSystem.IRandomFactory Random { get; }`
`126`	`126`	`public Testably.Abstractions.Testing.RandomSystem.IRandomProvider RandomProvider { get; }`