CSHARP-4730: Always encode CompressionType.ZStandard as zstd. (#1207)

Author: JamesKovacs

src/MongoDB.Driver/MongoClientSettings.cs

@@ -20,6 +20,7 @@
 using System.Text;
 using MongoDB.Bson;
 using MongoDB.Driver.Core.Clusters;
+using MongoDB.Driver.Core.Compression;
 using MongoDB.Driver.Core.Configuration;
 using MongoDB.Driver.Core.Misc;
 using MongoDB.Driver.Encryption;
@@ -1221,7 +1222,7 @@ public override string ToString()
             }
             if (_compressors?.Any() ?? false)
             {
-                sb.AppendFormat("Compressors=[{0}];", string.Join(",", _compressors));
+                sb.AppendFormat("Compressors=[{0}];", string.Join(",", _compressors.Select(x => CompressorTypeMapper.ToServerName(x.Type))));
             }
             if (_connectionModeSwitch == ConnectionModeSwitch.UseConnectionMode)
             {

src/MongoDB.Driver/MongoUrlBuilder.cs

@@ -923,7 +923,7 @@ public override string ToString()
 
             if (_compressors?.Any() ?? false)
             {
-                query.AppendFormat("compressors={0}&", string.Join(",", _compressors.Select(x => x.Type.ToString().ToLowerInvariant())));
+                query.AppendFormat("compressors={0}&", string.Join(",", _compressors.Select(x => CompressorTypeMapper.ToServerName(x.Type))));
                 foreach (var compressor in _compressors)
                 {
                     ParseAndAppendCompressorOptions(query, compressor);

tests/MongoDB.Driver.Tests/MongoClientSettingsTests.cs

@@ -188,6 +188,20 @@ public void TestCompressors()
             Assert.Throws<InvalidOperationException>(() => { settings.Compressors = compressors; });
         }
 
+        [Theory]
+        [InlineData(new[]{CompressorType.Snappy}, "Compressors=[snappy]")]
+        [InlineData(new[]{CompressorType.Zlib}, "Compressors=[zlib]")]
+        [InlineData(new[]{CompressorType.ZStandard}, "Compressors=[zstd]")]
+        [InlineData(new[]{CompressorType.ZStandard, CompressorType.Snappy, CompressorType.Zlib}, "Compressors=[zstd,snappy,zlib]")]
+        public void Compressors_ToString_outputs_correct_compressors(CompressorType[] compressors, string expectedConnectionString)
+        {
+            var settings = new MongoClientSettings {Compressors = compressors.Select(x => new CompressorConfiguration(x)).ToList()};
+
+            var result = settings.ToString();
+
+            Assert.Contains(expectedConnectionString, result);
+        }
+
 #pragma warning disable CS0618 // Type or member is obsolete
         [Fact]
         public void TestConnectionMode()

tests/MongoDB.Driver.Tests/MongoUrlBuilderTests.cs

@@ -346,39 +346,32 @@ public void TestComputedWaitQueueSize_UsingSize()
         }
 
         [Theory]
-        [InlineData(null, null, "mongodb://localhost", null)]
-        [InlineData(new[] { CompressorType.Zlib }, null, "mongodb://localhost/?compressors={0}", new[] { CompressorType.Zlib })]
-        [InlineData(new[] { CompressorType.Zlib }, "Level&zlibCompressionLevel&1", "mongodb://localhost/?compressors={0}", new[] { CompressorType.Zlib })]
-        [InlineData(new[] { CompressorType.Snappy }, null, "mongodb://localhost/?compressors={0}", new[] { CompressorType.Snappy })]
-        [InlineData(new[] { CompressorType.Snappy, CompressorType.Zlib }, null, "mongodb://localhost/?compressors={0}", new[] { CompressorType.Snappy, CompressorType.Zlib })]
-        public void TestCompressors(CompressorType[] compressors, string compressionProperty, string formatString, CompressorType[] values)
+        [InlineData(null, "mongodb://localhost")]
+        [InlineData(new[] { CompressorType.Zlib }, "mongodb://localhost/?compressors=zlib")]
+        [InlineData(new[] { CompressorType.ZStandard }, "mongodb://localhost/?compressors=zstd")]
+        [InlineData(new[] { CompressorType.Snappy }, "mongodb://localhost/?compressors=snappy")]
+        [InlineData(new[] { CompressorType.Snappy, CompressorType.Zlib }, "mongodb://localhost/?compressors=snappy,zlib")]
+        [InlineData(new[] { CompressorType.ZStandard, CompressorType.Snappy, CompressorType.Zlib }, "mongodb://localhost/?compressors=zstd,snappy,zlib")]
+        public void TestCompressors(CompressorType[] compressors, string expectedConnectionString)
         {
             var subject = new MongoUrlBuilder { Server = _localhost };
-            if (compressors != null)
-            {
-                subject.Compressors = compressors
-                    .Select(x =>
-                    {
-                        var compression = new CompressorConfiguration(x);
-                        if (!string.IsNullOrWhiteSpace(compressionProperty))
-                        {
-                            var @params = compressionProperty.Split('&');
-                            compression.Properties.Add(@params[0], @params[2]);
-                        }
-                        return compression;
-                    })
-                    .ToList();
-            }
 
-            Assert.Equal(compressors ?? new CompressorType[0], subject.Compressors.Select(x => x.Type));
-            var expectedValues = values == null ? string.Empty : string.Join(",", values.Select(c => c.ToString().ToLower()));
-            if (!string.IsNullOrWhiteSpace(compressionProperty))
-            {
-                var @params = compressionProperty.Split('&');
-                expectedValues += $"&{@params[1]}={@params[2]}";
-            }
-            var canonicalConnectionString = string.Format(formatString, expectedValues);
-            Assert.Equal(canonicalConnectionString, subject.ToString());
+            subject.Compressors = compressors?.Select(x => new CompressorConfiguration(x)).ToList();
+            var connectionString = subject.ToString();
+
+            Assert.Equal(expectedConnectionString, connectionString);
+        }
+
+        [Fact]
+        public void TestCompressorProperties()
+        {
+            var subject = new MongoUrlBuilder { Server = _localhost };
+
+            var zlibCompressor = new CompressorConfiguration(CompressorType.Zlib) { Properties = {{ "Level", 1 }} };
+            subject.Compressors = new[] { zlibCompressor };
+            var connectionString = subject.ToString();
+
+            Assert.Equal("mongodb://localhost/?compressors=zlib&zlibCompressionLevel=1", connectionString);
         }
 
         [Theory]