Updated OpenApiWorkspaceLoader to support loading external references

Author: darrelmiller

src/Microsoft.OpenApi.Readers/OpenApiReaderSettings.cs

@@ -3,10 +3,13 @@
 
 using Microsoft.OpenApi.Any;
 using Microsoft.OpenApi.Interfaces;
+using Microsoft.OpenApi.Readers.Interface;
 using Microsoft.OpenApi.Readers.ParseNodes;
+using Microsoft.OpenApi.Readers.Services;
 using Microsoft.OpenApi.Validations;
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
@@ -56,5 +59,13 @@ public class OpenApiReaderSettings
         /// URL where relative references should be resolved from if the description does not contain Server definitions
         /// </summary>
         public Uri BaseUrl { get; set; }
+
+        /// <summary>
+        /// Function used to provide an alternative loader for accessing external references.  
+        /// </summary>
+        /// <remarks>
+        /// Default loader will attempt to dereference http(s) urls and file urls.
+        /// </remarks>
+        public Func<Uri, Task<Stream>> CustomExternalLoader { get; set; }
     }
 }

src/Microsoft.OpenApi.Readers/OpenApiYamlDocumentReader.cs

@@ -2,6 +2,7 @@
 // Licensed under the MIT license. 
 
 using System;
+using System.IO;
 using Microsoft.OpenApi.Exceptions;
 using Microsoft.OpenApi.Extensions;
 using Microsoft.OpenApi.Interfaces;
@@ -54,6 +55,14 @@ public OpenApiDocument Read(YamlDocument input, out OpenApiDiagnostic diagnostic
                 switch (_settings.ReferenceResolution)
                 {
                     case ReferenceResolutionSetting.ResolveAllReferences:
+                        var openApiWorkSpace = new OpenApiWorkspace();
+                        document.Workspace = openApiWorkSpace;
+                        var streamLoader = new DefaultStreamLoader();
+                        
+                        var workspaceLoader = new OpenApiWorkspaceLoader(openApiWorkSpace, _settings.CustomExternalLoader ?? streamLoader.LoadAsync, _settings);
+                        workspaceLoader.LoadAsync(new OpenApiReference() { ExternalResource="/" }, document);
+
+                        // TODO:  Need to add ReadAsync for resolving all references.
                         throw new ArgumentException(Properties.SRResource.CannotResolveRemoteReferencesSynchronously);
                     case ReferenceResolutionSetting.ResolveLocalReferences:
                         var errors = document.ResolveReferences(false);

src/Microsoft.OpenApi.Readers/Services/OpenApiWorkspaceLoader.cs

@@ -7,21 +7,22 @@
 using Microsoft.OpenApi.Models;
 using Microsoft.OpenApi.Readers.Interface;
 using Microsoft.OpenApi.Services;
+using SharpYaml.Model;
 
 namespace Microsoft.OpenApi.Readers.Services
 {
-    internal class OpenApiWorkspaceLoader<TInput,TDiagnostic> where TDiagnostic: IDiagnostic
+    internal class OpenApiWorkspaceLoader 
     {
         private OpenApiWorkspace _workspace;
-        private IInputLoader<TInput> _loader;
-        private TDiagnostic _diagnostics;
-        private IOpenApiReader<TInput, TDiagnostic> _reader;
+        private Func<Uri, Task<Stream>> _loader;
+        private OpenApiDiagnostic _diagnostics;
+        private OpenApiReaderSettings _readerSettings;
 
-        public OpenApiWorkspaceLoader(OpenApiWorkspace workspace, IInputLoader<TInput> loader, IOpenApiReader<TInput, TDiagnostic> reader)
+        public OpenApiWorkspaceLoader(OpenApiWorkspace workspace, Func<Uri,Task<Stream>> loader, OpenApiReaderSettings readerSettings)
         {
             _workspace = workspace;
             _loader = loader;
-            _reader = reader;
+            _readerSettings = readerSettings;
         }
 
         internal async Task LoadAsync(OpenApiReference reference, OpenApiDocument document)
@@ -34,14 +35,16 @@ internal async Task LoadAsync(OpenApiReference reference, OpenApiDocument docume
             var collectorWalker = new OpenApiWalker(referenceCollector);
             collectorWalker.Walk(document);
 
+            var reader = new OpenApiStreamReader(_readerSettings);
+
             // Walk references
             foreach (var item in referenceCollector.References)
             {
                 // If not already in workspace, load it and process references
                 if (!_workspace.Contains(item.ExternalResource))
                 {
-                    var input = await _loader.LoadAsync(new Uri(item.ExternalResource));
-                    var newDocument = _reader.Read(input, out _diagnostics);
+                    var input = await _loader(new Uri(item.ExternalResource));
+                    var newDocument = reader.Read(input, out _diagnostics); // TODO merge _diagnositics
                     await LoadAsync(item, newDocument);
                 }
             }

test/Microsoft.OpenApi.Readers.Tests/OpenApiWorkspaceTests/OpenApiWorkspaceStreamTests.cs

@@ -1,12 +1,37 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using Microsoft.OpenApi.Models;
+using Microsoft.OpenApi.Readers.Interface;
+using Microsoft.OpenApi.Readers.Services;
+using Microsoft.OpenApi.Services;
+using Xunit;
 
 namespace Microsoft.OpenApi.Readers.Tests.OpenApiWorkspaceTests
 {
-    class OpenApiWorkspaceStreamTests
+    public class OpenApiWorkspaceStreamTests
     {
+
+
+        // Use OpenApiWorkspace to load a document and a referenced document
+
+        //[Fact]
+        public void LoadDocumentIntoWorkspace()
+        {
+            // Create a reader that will resolve all references
+            var reader = new OpenApiStringReader(new OpenApiReaderSettings() {
+                ReferenceResolution = ReferenceResolutionSetting.ResolveAllReferences, 
+                CustomExternalLoader = (url) => { return null; }
+            });
+
+            // Todo: this should be ReadAsync
+            var doc = reader.Read("", out OpenApiDiagnostic diagnostic);
+
+            Assert.NotNull(doc.Workspace);
+
+        }
     }
 }