Add support for passing API spec variables values. Closes #1019 (#1074)

Author: waldekmastykarz

dev-proxy-abstractions/IProxyConfiguration.cs

@@ -11,6 +11,7 @@ public interface IProxyConfiguration
     int ApiPort { get; }
     bool AsSystemProxy { get; }
     string ConfigFile { get; }
+    Dictionary<string, string> Env { get; set; }
     MockRequestHeader[]? FilterByHeaders { get; }
     bool InstallCert { get; }
     string? IPAddress { get; }

dev-proxy-abstractions/ProxyUtils.cs

@@ -496,4 +496,18 @@ private static string GetCommonPrefix(List<string> paths)
             return (false, [ex.Message]);
         }
     }
+
+    public static string ReplaceVariables(string s, Dictionary<string, string> variables, Func<string, string>? formatVariableRef = null)
+    {
+        formatVariableRef ??= v => $"@{v}";
+
+        var s1 = s;
+
+        foreach (var variable in variables)
+        {
+            s1 = s1.Replace(formatVariableRef(variable.Key), variable.Value, StringComparison.OrdinalIgnoreCase);
+        }
+
+        return s1;
+    }
 }

dev-proxy-plugins/RequestLogs/MinimalPermissionsGuidancePlugin.cs

@@ -187,7 +187,10 @@ private Dictionary<string, OpenApiDocument> LoadApiSpecs(string apiSpecsFolderPa
             Logger.LogDebug("Processing file '{file}'...", file);
             try
             {
-                var apiDefinition = new OpenApiStringReader().Read(File.ReadAllText(file), out _);
+                var fileContents = File.ReadAllText(file);
+                fileContents = ProxyUtils.ReplaceVariables(fileContents, Context.Configuration.Env, v => $"{{{v}}}");
+
+                var apiDefinition = new OpenApiStringReader().Read(fileContents, out _);
                 if (apiDefinition is null)
                 {
                     continue;

dev-proxy-plugins/RequestLogs/MinimalPermissionsPlugin.cs

@@ -68,8 +68,7 @@ private async Task AfterRecordingStopAsync(object sender, RecordingArgs e)
             .Where(l =>
                 l.MessageType == MessageType.InterceptedRequest &&
                 !l.Message.StartsWith("OPTIONS") &&
-                l.Context?.Session is not null &&
-                l.Context.Session.HttpClient.Request.Headers.Any(h => h.Name.Equals("authorization", StringComparison.OrdinalIgnoreCase))
+                l.Context?.Session is not null
             );
         if (!interceptedRequests.Any())
         {
@@ -165,7 +164,10 @@ private Dictionary<string, OpenApiDocument> LoadApiSpecs(string apiSpecsFolderPa
             Logger.LogDebug("Processing file '{file}'...", file);
             try
             {
-                var apiDefinition = new OpenApiStringReader().Read(File.ReadAllText(file), out _);
+                var fileContents = File.ReadAllText(file);
+                fileContents = ProxyUtils.ReplaceVariables(fileContents, Context.Configuration.Env, v => $"{{{v}}}");
+
+                var apiDefinition = new OpenApiStringReader().Read(fileContents, out _);
                 if (apiDefinition is null)
                 {
                     continue;

dev-proxy/CommandHandlers/ProxyCommandHandler.cs

@@ -161,6 +161,20 @@ private void ParseOptions(InvocationContext context)
         {
             Configuration.Record = true;
         }
+        var env = context.ParseResult.GetValueForOption<string[]?>(ProxyHost.EnvOptionName, _options);
+        if (env is not null)
+        {
+            Configuration.Env = env.Select(e =>
+            {
+                // Split on first '=' only
+                var parts = e.Split('=', 2);
+                if (parts.Length != 2)
+                {
+                    throw new ArgumentException($"Invalid env format: {e}. Expected format is 'key=value'.");
+                }
+                return new KeyValuePair<string, string>(parts[0], parts[1]);
+            }).ToDictionary(kvp => kvp.Key, kvp => kvp.Value);
+        }
     }
 
     private async Task CheckForNewVersionAsync()

dev-proxy/ProxyConfiguration.cs

@@ -24,6 +24,7 @@ public class ProxyConfiguration : IProxyConfiguration
     public int ApiPort { get; set; } = 8897;
     public bool AsSystemProxy { get; set; } = true;
     public string ConfigFile { get; set; } = "devproxyrc.json";
+    public Dictionary<string, string> Env { get; set; } = [];
     public MockRequestHeader[]? FilterByHeaders { get; set; }
     public string? IPAddress { get; set; } = "127.0.0.1";
     public bool InstallCert { get; set; } = true;

dev-proxy/ProxyHost.cs

@@ -39,6 +39,8 @@ internal class ProxyHost
     private readonly Option<long?> _timeoutOption;
     internal static readonly string DiscoverOptionName = "--discover";
     private readonly Option<bool?> _discoverOption;
+    internal static readonly string EnvOptionName = "--env";
+    private readonly Option<string[]?> _envOption;
 
     private static bool _configFileResolved = false;
     private static string _configFile = "devproxyrc.json";
@@ -273,7 +275,7 @@ public ProxyHost()
             Arity = ArgumentArity.ZeroOrMore
         };
         _urlsToWatchOption.AddAlias("-u");
-        
+
         _timeoutOption = new Option<long?>(TimeoutOptionName, "Time in seconds after which Dev Proxy exits. Resets when Dev Proxy intercepts a request.")
         {
             ArgumentHelpName = "timeout",
@@ -294,6 +296,40 @@ public ProxyHost()
         });
         _timeoutOption.AddAlias("-t");
 
+        _envOption = new Option<string[]?>(EnvOptionName, "Variables to set for the Dev Proxy process")
+        {
+            ArgumentHelpName = "env",
+            AllowMultipleArgumentsPerToken = true,
+            Arity = ArgumentArity.ZeroOrMore
+        };
+        _envOption.AddAlias("-e");
+        _envOption.AddValidator(input =>
+        {
+            try
+            {
+                var envVars = input.GetValueForOption(_envOption);
+                if (envVars is null || envVars.Length == 0)
+                {
+                    return;
+                }
+
+                foreach (var envVar in envVars)
+                {
+                    // Split on first '=' only
+                    var parts = envVar.Split('=', 2);
+                    if (parts.Length != 2)
+                    {
+                        input.ErrorMessage = $"Invalid environment variable format: '{envVar}'. Expected format is 'name=value'.";
+                        return;
+                    }
+                }
+            }
+            catch (InvalidOperationException ex)
+            {
+                input.ErrorMessage = ex.Message;
+            }
+        });
+
         ProxyCommandHandler.Configuration.ConfigFile = ConfigFile;
     }
 
@@ -318,7 +354,8 @@ public RootCommand GetRootCommand(ILogger logger)
             // As such, it's always set here
             _urlsToWatchOption!,
             _timeoutOption,
-            _discoverOption
+            _discoverOption,
+            _envOption
         };
         command.Description = "Dev Proxy is a command line tool for testing Microsoft Graph, SharePoint Online and any other HTTP APIs.";
 
@@ -492,6 +529,7 @@ public RootCommand GetRootCommand(ILogger logger)
             _installCertOption,
             _timeoutOption,
             _discoverOption,
+            _envOption,
             .. optionsFromPlugins,
         ],
         urlsToWatch,