Remove redundant routes

Burgyn · Dec 3, 2023 · bb579b1 · bb579b1
1 parent 698d55b
commit bb579b1
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Showing 3 changed files with 31 additions and 5 deletions.
diff --git a/src/MMLib.SwaggerForOcelot/Aggregates/RoutesDocumentationProvider.cs b/src/MMLib.SwaggerForOcelot/Aggregates/RoutesDocumentationProvider.cs
@@ -46,7 +46,7 @@ private RouteDocs GetRouteDocs(RouteOptions route)
             JToken paths = docs[OpenApiProperties.Paths];
             string downstreamPath = GetDownstreamPath(route);
             JProperty path = paths.OfType<JProperty>().FirstOrDefault(p =>
-                downstreamPath.Equals(p.Name.WithSlashEnding(), StringComparison.CurrentCultureIgnoreCase));
+                downstreamPath.Equals(p.Name.WithSlashEnding(), StringComparison.OrdinalIgnoreCase));
 
             return new RouteDocs()
             {

diff --git a/src/MMLib.SwaggerForOcelot/Configuration/RouteOptions.cs b/src/MMLib.SwaggerForOcelot/Configuration/RouteOptions.cs
@@ -162,7 +162,7 @@ private string DownstreamPathWithVirtualDirectory
         /// Gets a value indicating whether this instance can catch all.
         /// </summary>
         public bool CanCatchAll
-            => DownstreamPathTemplate.EndsWith(CatchAllPlaceHolder, StringComparison.CurrentCultureIgnoreCase);
+            => DownstreamPathTemplate.EndsWith(CatchAllPlaceHolder, StringComparison.OrdinalIgnoreCase);
 
         /// <summary>
         /// Gets the upstream path.

diff --git a/src/MMLib.SwaggerForOcelot/Transformation/SwaggerJsonTransformer.cs b/src/MMLib.SwaggerForOcelot/Transformation/SwaggerJsonTransformer.cs
@@ -171,7 +171,7 @@ private string TransformOpenApi(
         private void RenameAndRemovePaths(IEnumerable<RouteOptions> routes, JToken paths, string basePath)
         {
             var oldPaths = new List<JProperty>();
-            var newPaths = new Dictionary<string, JProperty>();
+            var newPaths = new Dictionary<string, JProperty>(StringComparer.OrdinalIgnoreCase);
             for (int i = 0; i < paths.Count(); i++)
             {
                 var oldPath = paths.ElementAt(i) as JProperty;
@@ -281,9 +281,35 @@ static bool MatchPaths(RouteOptions route, string downstreamPath)
                     : route.DownstreamPathWithSlash.Equals(downstreamPath, StringComparison.OrdinalIgnoreCase);
 
             string downstreamPathWithBasePath = PathHelper.BuildPath(basePath, downstreamPath);
-            return routes
+            var matchedRoutes = routes
                 .Where(route => route.ContainsHttpMethod(method) && MatchPaths(route, downstreamPathWithBasePath))
                 .ToList();
+
+            RemoveRedundantRoutes(matchedRoutes);
+            return matchedRoutes;
+        }
+
+        // Redundant routes are routes with the ALMOST same upstream path templates. For example these path templates
+        // are redundant:
+        //   - /api/projects/Projects
+        //   - /api/projects/Projects/
+        //   - /api/projects/Projects/{everything}
+        //
+        // `route.UpstreamPath` contains route without trailing slash and without catch-all placeholder, so all previous
+        // routes have the same upstream path `/api/projects/Projects`. The logic is to keep just the shortestof the path
+        // templates. If we would keep all routes, it will throw an exception during the generation of the swagger document
+        // later because of the same paths.
+        private static void RemoveRedundantRoutes(List<RouteOptions> routes)
+        {
+            IEnumerable<IGrouping<string, RouteOptions>> groups = routes
+                .GroupBy(route => route.UpstreamPath, StringComparer.OrdinalIgnoreCase)
+                .Where(group => group.Count() > 1);
+            foreach (var group in groups)
+            {
+                group.OrderBy(r => r.DownstreamPathTemplate.Length)
+                    .Skip(1)
+                    .ForEach(r => routes.Remove(r));
+            }
         }
 
         private static void AddHost(JObject swagger, string swaggerHost)
@@ -305,7 +331,7 @@ private static string ConvertDownstreamPathToUpstreamPath(string downstreamPath,
                 downstreamPath = PathHelper.BuildPath(downstreamBasePath, downstreamPath);
             }
 
-            int pos = downstreamPath.IndexOf(downstreamPattern, StringComparison.CurrentCultureIgnoreCase);
+            int pos = downstreamPath.IndexOf(downstreamPattern, StringComparison.OrdinalIgnoreCase);
             if (pos < 0)
             {
                 return downstreamPath;