Fix misleading mock sort comment and use stable sort in MockGeneratorPlugin. Closes #1974 (#1997)

The comment claimed mocks are sorted by URL length so that the most
specific comes first, but the code sorts by descending ordinal URL.
Generated mocks use exact URLs, so the order doesn't affect matching.
Update the comment to reflect this and replace the unstable List.Sort
with a stable OrderByDescending so repeated requests to the same URL
keep their recorded order.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: e010e7fb-27f1-4b60-b3a6-1717b55ced91

Author: waldekmastykarz

DevProxy.Integration.Tests/GenerationPluginsIntegrationTests.cs

@@ -161,6 +161,49 @@ public async Task MockGenerator_WritesMockFile()
         }
     }
 
+    [Fact]
+    public async Task MockGenerator_PreservesRecordedOrderForSameUrl()
+    {
+        var plugin = new MockGeneratorPlugin(NullLogger<MockGeneratorPlugin>.Instance, Watch);
+
+        // enough entries to exceed the insertion-sort threshold of an unstable sort
+        const int count = 40;
+        var logs = Enumerable.Range(0, count)
+            .Select(i => TestExchange
+                .Request("GET", i % 2 == 0 ? "https://api.contoso.com/a" : "https://api.contoso.com/b")
+                .WithResponse(
+                    HttpStatusCode.OK,
+                    headers: [("Content-Type", "application/json")],
+                    body: $$"""{ "seq": {{i}} }""")
+                .AsRequestLog(MessageType.InterceptedResponse))
+            .ToList();
+
+        var args = Recording(logs);
+        var dir = await InTempCwdAsync(() => plugin.AfterRecordingStopAsync(args, CancellationToken.None));
+        try
+        {
+            var mockFile = dir.GetFiles("mocks-*.json").Single();
+            using var doc = JsonDocument.Parse(await File.ReadAllTextAsync(mockFile.FullName));
+            var mocks = doc.RootElement.GetProperty("mocks").EnumerateArray()
+                .Select(m => (
+                    Url: m.GetProperty("request").GetProperty("url").GetString(),
+                    Seq: m.GetProperty("response").GetProperty("body").GetProperty("seq").GetInt32()))
+                .ToArray();
+
+            Assert.Equal(count, mocks.Length);
+
+            var expected = Enumerable.Range(0, count).Where(i => i % 2 == 1)
+                .Select(i => ("https://api.contoso.com/b", i))
+                .Concat(Enumerable.Range(0, count).Where(i => i % 2 == 0)
+                    .Select(i => ("https://api.contoso.com/a", i)));
+            Assert.Equal(expected, mocks.Select(m => (m.Url!, m.Seq)));
+        }
+        finally
+        {
+            dir.Delete(recursive: true);
+        }
+    }
+
     [Fact]
     public async Task HttpFileGenerator_WritesHttpFile()
     {

DevProxy.Plugins/Generation/MockGeneratorPlugin.cs

@@ -81,8 +81,10 @@ request.Context.Session is null ||
         }
 
         Logger.LogDebug("Sorting mocks...");
-        // sort mocks descending by url length so that most specific mocks are first
-        mocks.Sort((a, b) => string.CompareOrdinal(b.Request!.Url, a.Request!.Url));
+        // group mocks by URL (descending ordinal order) for readability. Generated
+        // mocks use exact URLs, so this order doesn't affect matching. The sort is
+        // stable so that repeated requests to the same URL keep their recorded order.
+        mocks = [.. mocks.OrderByDescending(m => m.Request!.Url, StringComparer.Ordinal)];
 
         var mocksFile = new MockResponseConfiguration { Mocks = mocks };