feat: support IPFS_PATH, closes #12

doc/articles/envvars.md

@@ -7,3 +7,4 @@ are used  to control the behaviour of the library
 | --- | --- |
 | HOME | The user's home directory |
 | HOMEPATH | same as `HOME` |
+| IPFS_PATH | The folder of the IPFS [repository](repository) |

doc/articles/repository.md

@@ -2,4 +2,6 @@
 
 The repository is a persistent store for IPFS data. By default, it is located at `$HOME/.csipfs`.  If not present, the [IPFS Engine](xref:Ipfs.Engine.IpfsEngine) will create it with the factory defaults.
 
+To change its name and/or location use the [environment variables](envvars) or the [Repository Options](xref:Ipfs.Engine.IpfsEngine.RepositoryOptions)
+
 A [SQLite database](https://sqlite.org/), named `ipfs.db`, stores most of the information.  You can use [DB Browser](http://sqlitebrowser.org/) to examine and modify the information.

src/Cryptography/KeyChainOptions.cs

@@ -9,6 +9,7 @@ namespace Ipfs.Engine.Cryptography
     /// <summary>
     ///   Configuration options for the <see cref="KeyChain"/>.
     /// </summary>
+    /// <seealso cref="IpfsEngine.Options"/>
     public class KeyChainOptions
     {
         /// <summary>

src/IpfsEngineOptions.cs

@@ -10,6 +10,7 @@ namespace Ipfs.Engine
     /// <summary>
     ///   Configuration options for the <see cref="IpfsEngine"/>.
     /// </summary>
+    /// <seealso cref="IpfsEngine.Options"/>
     public class IpfsEngineOptions
     {
         /// <summary>

src/RepositoryOptions.cs

@@ -10,16 +10,37 @@ namespace Ipfs.Engine
     /// <summary>
     ///   Configuration options for the <see cref="Repository"/>.
     /// </summary>
+    /// <seealso cref="IpfsEngineOptions"/>
     public class RepositoryOptions
     {
+        /// <summary>
+        ///   Creates a new instance of the <see cref="RepositoryOptions"/> class
+        ///   with the default values.
+        /// </summary>
+        public RepositoryOptions()
+        {
+            var path = Environment.GetEnvironmentVariable("IPFS_PATH");
+            if (path != null)
+            {
+                Folder = path;
+            }
+            else
+            {
+                Folder = Path.Combine(
+                    Environment.GetEnvironmentVariable("HOME") ??
+                    Environment.GetEnvironmentVariable("HOMEPATH"),
+                    ".csipfs");
+            }
+        }
+
         /// <summary>
         ///   The directory of the repository.
         /// </summary>
+        /// <value>
+        ///   The default value is <c>$IPFS_PATH</c> or <c>$HOME/.csipfs</c> or
+        ///   <c>$HOMEPATH/.csipfs</c>.
+        /// </value>
         public string Folder { get; set; }
-            = Path.Combine(
-                Environment.GetEnvironmentVariable("HOME") ??
-                Environment.GetEnvironmentVariable("HOMEPATH"),
-                ".csipfs");
 
         /// <summary>
         ///   The fully qualified name of the database.

test/RepositoryOptionsTest.cs

@@ -0,0 +1,129 @@
+using Ipfs.Engine.Cryptography;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Newtonsoft.Json.Linq;
+using System;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Ipfs.Engine
+{
+
+    [TestClass]
+    public class RepositoryOptionsTest
+    {
+        [TestMethod]
+        public void Defaults()
+        {
+            var options = new RepositoryOptions();
+            Assert.IsNotNull(options.Folder);
+            Assert.IsNotNull(options.DatabaseName);
+        }
+
+        [TestMethod]
+        public void Folder()
+        {
+            var options = new RepositoryOptions { Folder = "x" };
+            var sep = Path.DirectorySeparatorChar;
+            Assert.AreEqual($"x{sep}ipfs.db", options.DatabaseName);
+        }
+
+        [TestMethod]
+        public void Environment_Home()
+        {
+            var names = new string[] { "IPFS_PATH", "HOME", "HOMEPATH" };
+            var values = names.Select(n => Environment.GetEnvironmentVariable(n));
+            var sep = Path.DirectorySeparatorChar;
+            try
+            {
+                foreach (var name in names)
+                {
+                    Environment.SetEnvironmentVariable(name, null);
+                }
+                Environment.SetEnvironmentVariable("HOME", $"{sep}home1");
+                var options = new RepositoryOptions();
+                Assert.AreEqual($"{sep}home1{sep}.csipfs", options.Folder);
+                Assert.AreEqual($"{sep}home1{sep}.csipfs{sep}ipfs.db", options.DatabaseName);
+
+                Environment.SetEnvironmentVariable("HOME", $"{sep}home2{sep}");
+                options = new RepositoryOptions();
+                Assert.AreEqual($"{sep}home2{sep}.csipfs", options.Folder);
+                Assert.AreEqual($"{sep}home2{sep}.csipfs{sep}ipfs.db", options.DatabaseName);
+            }
+            finally
+            {
+                var pairs = names.Zip(values, (name, value) => new { name = name, value = value });
+                foreach (var pair in pairs)
+                {
+                    Environment.SetEnvironmentVariable(pair.name, pair.value);
+                }
+            }
+        }
+
+        [TestMethod]
+        public void Environment_HomePath()
+        {
+            var names = new string[] { "IPFS_PATH", "HOME", "HOMEPATH" };
+            var values = names.Select(n => Environment.GetEnvironmentVariable(n));
+            var sep = Path.DirectorySeparatorChar;
+            try
+            {
+                foreach (var name in names)
+                {
+                    Environment.SetEnvironmentVariable(name, null);
+                }
+                Environment.SetEnvironmentVariable("HOMEPATH", $"{sep}home1");
+                var options = new RepositoryOptions();
+                Assert.AreEqual($"{sep}home1{sep}.csipfs", options.Folder);
+                Assert.AreEqual($"{sep}home1{sep}.csipfs{sep}ipfs.db", options.DatabaseName);
+
+                Environment.SetEnvironmentVariable("HOMEPATH", $"{sep}home2{sep}");
+                options = new RepositoryOptions();
+                Assert.AreEqual($"{sep}home2{sep}.csipfs", options.Folder);
+                Assert.AreEqual($"{sep}home2{sep}.csipfs{sep}ipfs.db", options.DatabaseName);
+            }
+            finally
+            {
+                var pairs = names.Zip(values, (name, value) => new { name = name, value = value });
+                foreach (var pair in pairs)
+                {
+                    Environment.SetEnvironmentVariable(pair.name, pair.value);
+                }
+            }
+        }
+
+        [TestMethod]
+        public void Environment_IpfsPath()
+        {
+            var names = new string[] { "IPFS_PATH", "HOME", "HOMEPATH" };
+            var values = names.Select(n => Environment.GetEnvironmentVariable(n));
+            var sep = Path.DirectorySeparatorChar;
+            try
+            {
+                foreach (var name in names)
+                {
+                    Environment.SetEnvironmentVariable(name, null);
+                }
+                Environment.SetEnvironmentVariable("IPFS_PATH", $"{sep}x1");
+                var options = new RepositoryOptions();
+                Assert.AreEqual($"{sep}x1", options.Folder);
+                Assert.AreEqual($"{sep}x1{sep}ipfs.db", options.DatabaseName);
+
+                Environment.SetEnvironmentVariable("IPFS_PATH", $"{sep}x2{sep}");
+                options = new RepositoryOptions();
+                Assert.AreEqual($"{sep}x2{sep}", options.Folder);
+                Assert.AreEqual($"{sep}x2{sep}ipfs.db", options.DatabaseName);
+            }
+            finally
+            {
+                var pairs = names.Zip(values, (name, value) => new { name = name, value = value });
+                foreach (var pair in pairs)
+                {
+                    Environment.SetEnvironmentVariable(pair.name, pair.value);
+                }
+            }
+        }
+
+    }
+}