Adds support for server path variables. Closes #1292 (#1296)

Author: waldekmastykarz

DevProxy.Abstractions/Utils/ProxyUtils.cs

@@ -509,6 +509,15 @@ public static IEnumerable<string> GetWildcardPatterns(ReadOnlyCollection<string>
             .OrderBy(x => x)];
     }
 
+#pragma warning disable CA1055
+    public static string UrlWithParametersToRegex(string urlWithParameters)
+#pragma warning restore CA1055
+    {
+        ArgumentNullException.ThrowIfNull(urlWithParameters);
+
+        return $"^{Regex.Replace(Regex.Escape(urlWithParameters), "\\\\{[^}]+}", ".*")}";
+    }
+
     internal static Assembly GetAssembly()
             => _assembly ??= (Assembly.GetEntryAssembly() ?? Assembly.GetExecutingAssembly());
 

DevProxy.Plugins/Extensions/OpenApiDocumentExtensions.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using DevProxy.Abstractions.Proxy;
+using DevProxy.Abstractions.Utils;
 using DevProxy.Plugins.Models;
 using DevProxy.Plugins.Utils;
 using Microsoft.Extensions.Logging;
@@ -116,27 +117,26 @@ [.. operationsFromRequests
         {
             logger.LogDebug("Checking server URL {ServerUrl}...", server.Url);
 
-            if (!requestUrl.StartsWith(server.Url, StringComparison.OrdinalIgnoreCase))
+            if (!UrlMatchesServerUrl(requestUrl, server.Url))
             {
                 logger.LogDebug("Request URL {RequestUrl} does not match server URL {ServerUrl}", requestUrl, server.Url);
                 continue;
             }
 
-            var serverUrl = new Uri(server.Url);
-            var serverPath = serverUrl.AbsolutePath.TrimEnd('/');
             var requestUri = new Uri(requestUrl);
-            var urlPathFromRequest = requestUri.GetLeftPart(UriPartial.Path).Replace(server.Url.TrimEnd('/'), "", StringComparison.OrdinalIgnoreCase);
+            var absoluteUrlPathFromRequest = requestUri.GetLeftPart(UriPartial.Path);
 
             foreach (var path in openApiDocument.Paths)
             {
                 var urlPathFromSpec = path.Key;
-                logger.LogDebug("Checking path {UrlPath}...", urlPathFromSpec);
+                var absolutePathFromSpec = server.Url.TrimEnd('/') + urlPathFromSpec;
+                logger.LogDebug("Checking path {UrlPath}...", absolutePathFromSpec);
 
                 // check if path contains parameters. If it does,
                 // replace them with regex
-                if (urlPathFromSpec.Contains('{', StringComparison.OrdinalIgnoreCase))
+                if (absolutePathFromSpec.Contains('{', StringComparison.OrdinalIgnoreCase))
                 {
-                    logger.LogDebug("Path {UrlPath} contains parameters and will be converted to Regex", urlPathFromSpec);
+                    logger.LogDebug("Path {UrlPath} contains parameters and will be converted to Regex", absolutePathFromSpec);
 
                     // force replace all parameters with regex
                     // this is more robust than replacing parameters by name
@@ -147,24 +147,24 @@ [.. operationsFromRequests
                     // we also escape the path to make sure that regex special
                     // characters are not interpreted so that we won't fail
                     // on matching URLs that contain ()
-                    urlPathFromSpec = Regex.Replace(Regex.Escape(urlPathFromSpec), @"\\\{[^}]+\}", $"([^/]+)");
+                    absolutePathFromSpec = Regex.Replace(Regex.Escape(absolutePathFromSpec), @"\\\{[^}]+\}", $"([^/]+)");
 
-                    logger.LogDebug("Converted path to Regex: {UrlPath}", urlPathFromSpec);
-                    var regex = new Regex($"^{urlPathFromSpec}$");
-                    if (regex.IsMatch(urlPathFromRequest))
+                    logger.LogDebug("Converted path to Regex: {UrlPath}", absolutePathFromSpec);
+                    var regex = new Regex($"^{absolutePathFromSpec}$");
+                    if (regex.IsMatch(absoluteUrlPathFromRequest))
                     {
-                        logger.LogDebug("Regex matches {RequestUrl}", urlPathFromRequest);
+                        logger.LogDebug("Regex matches {RequestUrl}", absoluteUrlPathFromRequest);
 
                         return path;
                     }
 
-                    logger.LogDebug("Regex does not match {RequestUrl}", urlPathFromRequest);
+                    logger.LogDebug("Regex does not match {RequestUrl}", absoluteUrlPathFromRequest);
                 }
                 else
                 {
-                    if (urlPathFromRequest.Equals(urlPathFromSpec, StringComparison.OrdinalIgnoreCase))
+                    if (absoluteUrlPathFromRequest.Equals(absolutePathFromSpec, StringComparison.OrdinalIgnoreCase))
                     {
-                        logger.LogDebug("{RequestUrl} matches {UrlPath}", requestUrl, urlPathFromSpec);
+                        logger.LogDebug("{RequestUrl} matches {UrlPath}", requestUrl, absolutePathFromSpec);
                         return path;
                     }
 
@@ -216,4 +216,21 @@ public static OpenApiSecurityScheme[] GetOAuth2Schemes(this OpenApiDocument open
             .Where(s => s.Value.Type == SecuritySchemeType.OAuth2)
             .Select(s => s.Value)];
     }
+
+    private static bool UrlMatchesServerUrl(string absoluteUrl, string serverUrl)
+    {
+        if (absoluteUrl.StartsWith(serverUrl, StringComparison.OrdinalIgnoreCase))
+        {
+            return true;
+        }
+
+        // If serverUrl contains parameters, use regex to compare it
+        if (!serverUrl.Contains('{', StringComparison.Ordinal))
+        {
+            return false;
+        }
+
+        var serverUrlPattern = ProxyUtils.UrlWithParametersToRegex(serverUrl);
+        return Regex.IsMatch(absoluteUrl, serverUrlPattern, RegexOptions.IgnoreCase);
+    }
 }

DevProxy.Plugins/Reporting/MinimalPermissionsPlugin.cs

@@ -10,6 +10,7 @@
 using Microsoft.Extensions.Logging;
 using Microsoft.OpenApi.Models;
 using Microsoft.OpenApi.Readers;
+using System.Text.RegularExpressions;
 
 namespace DevProxy.Plugins.Reporting;
 
@@ -185,7 +186,17 @@ private async Task<Dictionary<string, OpenApiDocument>> LoadApiSpecsAsync(string
                         Logger.LogDebug("No URL found for server '{Server}'", server.Description ?? "unnamed");
                         continue;
                     }
-                    apiDefinitions[server.Url] = apiDefinition;
+
+                    Logger.LogDebug("Found server '{Server}' with URL '{Url}'", server.Description ?? "unnamed", server.Url);
+
+                    var serverUrl = server.Url;
+                    if (server.Url.Contains('{', StringComparison.Ordinal))
+                    {
+                        serverUrl = ProxyUtils.UrlWithParametersToRegex(server.Url);
+                        Logger.LogDebug("Transformed server URL '{OriginalUrl}' to '{TransformedUrl}'", server.Url, serverUrl);
+                    }
+
+                    apiDefinitions[serverUrl] = apiDefinition;
                 }
             }
             catch (Exception ex)
@@ -205,7 +216,9 @@ private async Task<Dictionary<string, OpenApiDocument>> LoadApiSpecsAsync(string
             var url = request.Message.Split(' ')[1];
             Logger.LogDebug("Matching request {RequestUrl} to API specs...", url);
 
-            var matchingKey = apiSpecsByUrl.Keys.FirstOrDefault(url.StartsWith);
+            var matchingKey = apiSpecsByUrl.Keys.FirstOrDefault(urlOrPattern =>
+                url.StartsWith(urlOrPattern, StringComparison.OrdinalIgnoreCase) ||
+                Regex.IsMatch(url, urlOrPattern));
             if (matchingKey is null)
             {
                 Logger.LogDebug("No matching API spec found for {RequestUrl}", url);