green: implemented HTTP #load

src/ConfigR.Roslyn.CSharp/ConfigR.Roslyn.CSharp.csproj

@@ -51,6 +51,7 @@
       <Link>Properties\CommonAssemblyInfo.cs</Link>
     </Compile>
     <Compile Include="App_Packages\LibLog.4.2\LibLog.cs" />
+    <Compile Include="Internal\HttpSourceFileResolver.cs" />
     <Compile Include="Internal\StringExtensions.cs" />
     <Compile Include="ScriptOptionsExtensions.cs" />
     <Compile Include="Internal\ScriptGlobals.cs" />

src/ConfigR.Roslyn.CSharp/Internal/HttpSourceFileResolver.cs

@@ -0,0 +1,58 @@
+// <copyright file="HttpSourceFileResolver.cs" company="ConfigR contributors">
+//  Copyright (c) ConfigR contributors. (configr.net@gmail.com)
+// </copyright>
+
+namespace ConfigR.Roslyn.CSharp.Internal
+{
+    using System;
+    using System.Collections.Immutable;
+    using System.IO;
+    using System.Net;
+    using ConfigR.Roslyn.CSharp.Logging;
+    using Microsoft.CodeAnalysis;
+    using static System.FormattableString;
+
+    [CLSCompliant(false)]
+    public class HttpSourceFileResolver : SourceFileResolver, IEquatable<HttpSourceFileResolver>
+    {
+        private static readonly ILog log = LogProvider.GetCurrentClassLogger();
+
+        [CLSCompliant(false)]
+        public HttpSourceFileResolver(ImmutableArray<string> searchPaths, string baseDirectory)
+            : base(searchPaths, baseDirectory)
+        {
+        }
+
+        public override string ResolveReference(string path, string baseFilePath)
+        {
+            Uri uri;
+            if (Uri.TryCreate(path, UriKind.Absolute, out uri) && (uri.Scheme == "http" || uri.Scheme == "https"))
+            {
+                path = Path.GetTempFileName();
+                log.InfoFormat("Downloading '{0}' to '{1}'.", uri.ToString(), path);
+
+                using (var response = WebRequest.Create(uri).GetResponse())
+                using (var responseStream = response.GetResponseStream())
+                using (var fileStream = File.OpenWrite(path))
+                {
+                    if (responseStream == null)
+                    {
+                        throw new InvalidOperationException(Invariant($"No response received from '{uri}'."));
+                    }
+
+                    responseStream.CopyTo(fileStream);
+                }
+
+                return path;
+            }
+
+            return base.ResolveReference(path, baseFilePath);
+        }
+
+        public bool Equals(HttpSourceFileResolver other) => base.Equals(other);
+
+        public override int GetHashCode() => base.GetHashCode();
+
+        public override bool Equals(object obj) => base.Equals(obj);
+    }
+}

src/ConfigR.Roslyn.CSharp/ScriptOptionsExtensions.cs

@@ -6,6 +6,7 @@ namespace ConfigR
 {
     using System;
     using System.Collections.Generic;
+    using System.Collections.Immutable;
     using System.IO;
     using System.Linq;
     using System.Reflection;
@@ -61,9 +62,12 @@ public static ScriptOptions ForConfigScript(this ScriptOptions options, string s
                 references.Add(assembly);
             }
 
+            var sourceResolver =
+                new HttpSourceFileResolver(searchPaths.ToImmutableArray(), ScriptSourceResolver.Default.BaseDirectory);
+
             return options
                 ?.WithMetadataResolver(ScriptMetadataResolver.Default.WithSearchPaths(searchPaths))
-                .WithSourceResolver(ScriptSourceResolver.Default.WithSearchPaths(searchPaths))
+                .WithSourceResolver(sourceResolver)
                 .AddReferences(references);
         }
     }