Add tests for special file

csharp/UnitTests/SpecialFileTests.cs

@@ -0,0 +1,102 @@
+using System.IO;
+using System.Threading.Tasks;
+using keyboards;
+using NUnit.Framework;
+
+namespace UnitTests
+{
+    public class SpecialFileTests
+    {
+        private static string ExistsPath => Path.GetTempFileName();
+        private static string NoPermsPath
+        {
+            get
+            {
+                var path = Path.GetTempFileName();
+                File.SetAttributes(path, FileAttributes.ReadOnly);
+                return path;
+            }
+        }
+
+        private const string NoExistsPath = "noexists";
+
+        [Test]
+        public void CanCheckExists()
+        {
+            var exists = new SpecialFile(ExistsPath);
+            var noExists = new SpecialFile(NoExistsPath);
+
+            Assert.IsTrue(exists.Exists);
+            Assert.IsFalse(noExists.Exists);
+        }
+
+        [Test]
+        public void HasWritePermissionsWithWritableFile()
+        {
+            var canWrite = new SpecialFile(ExistsPath);
+
+            Assert.IsTrue(canWrite.HasPermission);
+        }
+
+        [Test]
+        public void NoPermissionsWithReadOnlyFile()
+        {
+            var noWrite = new SpecialFile(NoPermsPath);
+            Assert.IsFalse(noWrite.HasPermission);
+        }
+
+        [Test]
+        public void PermissionsToNonExistingFile()
+        {
+            var noExists = new SpecialFile(NoExistsPath);
+            Assert.IsTrue(noExists.HasPermission);
+        }
+
+        [Test]
+        public async Task CanWriteToRegularFile()
+        {
+            var exists = new SpecialFile(Path.GetTempFileName());
+            await exists.Commit("test");
+            Assert.AreEqual("test", await exists.Read());
+            Assert.AreEqual("test", exists.Contents);
+            Assert.AreEqual("test", (await exists.Lines())[0]);
+        }
+
+        [Test]
+        public async Task CannotWriteToUnwritableFile()
+        {
+            var no = new SpecialFile(NoPermsPath);
+            await no.Commit("test");
+            Assert.AreEqual("", no.Contents);
+        }
+
+        [Test]
+        public void CanDeleteNonExistentFile()
+        {
+            Assert.IsFalse(File.Exists(NoExistsPath));
+            var no = new SpecialFile(NoExistsPath);
+            no.Delete();
+            Assert.DoesNotThrow(() => no.Delete());
+        }
+
+        [Test]
+        public void CanDeleteRegularFile()
+        {
+            var path = ExistsPath;
+            Assert.IsTrue(File.Exists(path));
+            var file = new SpecialFile(path);
+            Assert.DoesNotThrow(() => file.Delete());
+            Assert.IsFalse(File.Exists(path));
+        }
+
+        [Test]
+        public void CanDeleteReadOnlyFile()
+        {
+            var path = NoPermsPath;
+            Assert.IsTrue(File.Exists(path));
+            var file = new SpecialFile(path);
+            Assert.DoesNotThrow(() => file.Delete());
+            Assert.IsTrue(File.Exists(path));
+        }
+    }
+}