enable decompression methods during http get operations

src/NJsonSchema.Yaml.Tests/References/YamlReferencesTests.cs

@@ -50,7 +50,7 @@ public async Task When_yaml_OpenAPI_spec_has_external_schema_refs_they_are_resol
             OpenApiResponse Unauthorized = responses["401"].ActualResponse;
 
             ////Assert
-            
+
             // Header schema loaded correctly from headers.yaml
             Assert.True(OKheaders.ContainsKey(header));
             Assert.NotNull(OKheaders[header]);
@@ -62,6 +62,20 @@ public async Task When_yaml_OpenAPI_spec_has_external_schema_refs_they_are_resol
             Assert.NotNull(Unauthorized.Schema);
         }
 
+        [Theory]
+        [InlineData("https://www.zuora.com/developer/yaml/swagger.yaml", "https://rest.zuora.com/")]
+        public async Task When_yaml_OpenAPI_spec_is__served_with_gzip_compression__it_works(string inputYamlUrl, string expectedBaseUrl)
+        {
+            //// Act
+            OpenApiDocument doc = await OpenApiYamlDocument.FromUrlAsync(inputYamlUrl);
+
+            ////Assert
+            Assert.NotNull(doc);
+            Assert.NotNull(doc.Paths);
+            Assert.NotEmpty(doc.Paths);
+            Assert.Equal(expectedBaseUrl, doc.BaseUrl);
+        }
+
         [Theory]
         [InlineData("/References/YamlReferencesTest/subdir_spec/yaml_spec_with_yaml_schema_with_relative_subdir_refs.yaml")]
         public async Task When_yaml_OpenAPI_spec_has__relative_external_schema_refs_in_subdirs__they_are_resolved(string relativePath)

src/NJsonSchema/Infrastructure/DynamicApis.cs

@@ -25,6 +25,7 @@ public static class DynamicApis
         private static readonly Type FileType;
         private static readonly Type DirectoryType;
         private static readonly Type PathType;
+        private static readonly Type DecompressionMethodsType;
         private static readonly Type HttpClientHandlerType;
         private static readonly Type HttpClientType;
 
@@ -34,6 +35,10 @@ static DynamicApis()
                 "System.Xml.XPath.Extensions, System.Xml.XPath.XDocument",
                 "System.Xml.XPath.Extensions, System.Xml.Linq, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089");
 
+            DecompressionMethodsType = TryLoadType(
+                "System.Net.DecompressionMethods, System.Net.Primitives",
+                "System.Net.DecompressionMethods, System.Net.Primitives, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a");
+
             HttpClientHandlerType = TryLoadType(
                 "System.Net.Http.HttpClientHandler, System.Net.Http",
                 "System.Net.Http.HttpClientHandler, System.Net.Http, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a");
@@ -79,12 +84,34 @@ public static async Task<string> HttpGetAsync(string url, CancellationToken canc
             {
                 handler.UseDefaultCredentials = true;
 
+                // enable all decompression methods
+                var calculatedAllValue = GenerateAllDecompressionMethodsEnumValue();
+                var allDecompressionMethodsValue = Enum.ToObject(DecompressionMethodsType, calculatedAllValue);
+                handler.AutomaticDecompression = (dynamic)allDecompressionMethodsValue;
+
                 var response = await client.GetAsync(url, cancellationToken).ConfigureAwait(false);
                 response.EnsureSuccessStatusCode();
                 return await response.Content.ReadAsStringAsync().ConfigureAwait(false);
             }
         }
 
+        // see https://learn.microsoft.com/en-us/dotnet/api/system.net.decompressionmethods?view=net-7.0
+        private static int GenerateAllDecompressionMethodsEnumValue()
+        {
+            // calculate the set of all possible values (the set will depend on which version of the enum was loaded)
+            // NOTE: we can't use All or -1 since those weren't in the 4.0 version of the enum, but we
+            // still want to enable additional decompression methods like Brotli (and potentially
+            // additional ones in the future) if the loaded httpclient supports it.
+            // while the existing values would allow doing a Sum, we still bitwise or to be defensive about
+            // potential additions in the future of values like "GZipOrDeflate"
+            var calculatedAllValue = Enum.GetValues(DecompressionMethodsType)
+                .Cast<int>()
+                .Where(val => val > 0) // filter to only positive so we're not including All or None
+                .Aggregate(0, (accumulated, newValue) => accumulated | newValue);
+
+            return calculatedAllValue;
+        }
+
         /// <summary>Gets the current working directory.</summary>
         /// <returns>The directory path.</returns>
         /// <exception cref="NotSupportedException">The System.IO.Directory API is not available on this platform.</exception>