Add 6MB request and response size check

.autover/changes/e65c21d6-7608-481f-8135-198a7ab8ad54.json

@@ -0,0 +1,11 @@
+{
+  "Projects": [
+    {
+      "Name": "Amazon.Lambda.TestTool",
+      "Type": "Patch",
+      "ChangelogMessages": [
+        "Add 6MB request and response size validation."
+      ]
+    }
+  ]
+}

Tools/LambdaTestTool-v2/src/Amazon.Lambda.TestTool/Components/Pages/Home.razor

@@ -77,8 +77,26 @@ else
                 <label for="sample-requests">Example Requests</label>
             </div>
             <div class="mt-1 flex-grow-1 flex-fill">
-                <label class="form-label" for="function-payload">Function Input</label>
-                <StandaloneCodeEditor Id="function-payload" @ref="_editor" ConstructionOptions="EditorConstructionOptions" CssClass="rounded-4 overflow-hidden border"/>
+                <div class="d-flex justify-content-start align-items-center">
+                    <label class="form-label mb-0" for="function-payload">Function Input</label>
+                    @if (!string.IsNullOrEmpty(_errorMessage))
+                    {
+                        <div class="text-danger ms-auto">
+                            <i class="bi bi-exclamation-triangle-fill"></i>
+                        </div>
+                    }
+                </div>
+                <StandaloneCodeEditor
+                    Id="function-payload"
+                    @ref="_editor"
+                    ConstructionOptions="EditorConstructionOptions"
+                    CssClass="@($"rounded-4 overflow-hidden border {(!string.IsNullOrEmpty(_errorMessage) ? "border-danger border-2" : "")}")"/>
+                @if (!string.IsNullOrEmpty(_errorMessage))
+                {
+                    <div class="text-danger">
+                        @_errorMessage
+                    </div>
+                }
             </div>
         </div>
         <div class="col-lg-6 d-flex flex-column">

Tools/LambdaTestTool-v2/src/Amazon.Lambda.TestTool/Components/Pages/Home.razor.cs

@@ -1,6 +1,7 @@
 // Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
+using Amazon.Lambda.Model;
 using Microsoft.AspNetCore.Components;
 using Amazon.Lambda.TestTool.Services;
 using Amazon.Lambda.TestTool.Models;
@@ -9,6 +10,7 @@
 using BlazorMonaco.Editor;
 using Microsoft.JSInterop;
 using Microsoft.AspNetCore.WebUtilities;
+using Microsoft.Extensions.Options;
 
 namespace Amazon.Lambda.TestTool.Components.Pages;
 
@@ -21,6 +23,8 @@ public partial class Home : ComponentBase, IDisposable
     [Inject] public required IDirectoryManager DirectoryManager { get; set; }
     [Inject] public required IThemeService ThemeService { get; set; }
     [Inject] public required IJSRuntime JsRuntime { get; set; }
+    [Inject] public required ILambdaClient LambdaClient { get; set; }
+    [Inject] public IOptions<LambdaOptions> LambdaOptions { get; set; }
 
     private StandaloneCodeEditor? _editor;
     private StandaloneCodeEditor? _activeEditor;
@@ -33,6 +37,8 @@ public partial class Home : ComponentBase, IDisposable
 
     private const string NoSampleSelectedId = "void-select-request";
 
+    private string _errorMessage = string.Empty;
+
     private IDictionary<string, IList<LambdaRequest>> SampleRequests { get; set; } = new Dictionary<string, IList<LambdaRequest>>();
 
     private IRuntimeApiDataStore? DataStore { get; set; }
@@ -184,9 +190,12 @@ async Task OnAddEventClick()
             DataStore is null)
             return;
         var editorValue = await _editor.GetValue();
-        DataStore.QueueEvent(editorValue, false);
-        await _editor.SetValue(string.Empty);
-        SelectedSampleRequestName = NoSampleSelectedId;
+        var success = await InvokeLambdaFunction(editorValue);
+        if (success)
+        {
+            await _editor.SetValue(string.Empty);
+            SelectedSampleRequestName = NoSampleSelectedId;
+        }
         StateHasChanged();
     }
 
@@ -202,7 +211,7 @@ void OnClearExecuted()
         StateHasChanged();
     }
 
-    void OnRequeue(string awsRequestId)
+    async Task OnRequeue(string awsRequestId)
     {
         if (DataStore is null)
             return;
@@ -218,8 +227,7 @@ void OnRequeue(string awsRequestId)
 
         if (evnt == null)
             return;
-
-        DataStore.QueueEvent(evnt.EventJson, false);
+        await InvokeLambdaFunction(evnt.EventJson);
         StateHasChanged();
     }
 
@@ -326,4 +334,32 @@ private StandaloneEditorConstructionOptions ActiveErrorEditorConstructionOptions
             }
         };
     }
+
+    private async Task<bool> InvokeLambdaFunction(string payload)
+    {
+        var invokeRequest = new InvokeRequest
+        {
+            FunctionName = SelectedFunctionName,
+            Payload = payload,
+            InvocationType = InvocationType.Event
+        };
+
+        try
+        {
+            await LambdaClient.InvokeAsync(invokeRequest, LambdaOptions.Value.Endpoint);
+            _errorMessage = string.Empty;
+            return true;
+        }
+        catch (AmazonLambdaException e)
+        {
+            Logger.LogInformation(e.Message);
+
+            // lambda client automatically adds some extra verbiage: "The service returned an error with Error Code xxxx and HTTP Body: <bodyhere>".
+            // removing the extra verbiage to make the error message smaller and look better on the ui.
+            _errorMessage = e.Message.Contains("HTTP Body: ")
+                ? e.Message.Split("HTTP Body: ")[1]
+                : e.Message;
+        }
+        return false;
+    }
 }

Tools/LambdaTestTool-v2/src/Amazon.Lambda.TestTool/Exceptions.cs

@@ -0,0 +1,16 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+namespace Amazon.Lambda.TestTool;
+
+/// <summary>
+/// Contains constant string values for AWS Lambda exception types.
+/// </summary>
+public class Exceptions
+{
+    /// <summary>
+    /// Exception thrown when the request payload size exceeds AWS Lambda's limits.
+    /// This occurs when the request payload is larger than 6 MB for synchronous invocations.
+    /// </summary>
+    public const string RequestEntityTooLargeException = "RequestEntityTooLargeException";
+}

Tools/LambdaTestTool-v2/src/Amazon.Lambda.TestTool/Extensions/InvokeResponseExtensions.cs

@@ -6,6 +6,8 @@
 using Amazon.Lambda.Model;
 using Amazon.Lambda.TestTool.Models;
 
+namespace Amazon.Lambda.TestTool.Extensions;
+
 /// <summary>
 /// Provides extension methods for converting Lambda InvokeResponse to API Gateway response types.
 /// </summary>
@@ -83,6 +85,52 @@ public static APIGatewayProxyResponse ToApiGatewayErrorResponse(ApiGatewayEmulat
         }
     }
 
+    /// <summary>
+    /// Creates a standard API Gateway response for a "Request Entity Too Large" (413) error.
+    /// Not compatible with HTTP V2 API Gateway mode.
+    /// </summary>
+    /// <param name="emulatorMode">The API Gateway emulator mode (Rest or HttpV1 only).</param>
+    /// <returns>An APIGatewayProxyResponse configured with:
+    /// - Status code 413
+    /// - JSON error message ("Request Too Long" for REST, "Request Entity Too Large" for HTTP V1)
+    /// - Content-Type header set to application/json
+    /// </returns>
+    /// <exception cref="InvalidOperationException">Thrown when emulatorMode is HttpV2 or invalid value</exception>
+    /// <remarks>
+    /// This method only supports REST and HTTP V1 API Gateway modes. For HTTP V2,
+    /// use <seealso cref="ToHttpApiV2RequestTooLargeResponse"/>.
+    /// </remarks>
+    public static APIGatewayProxyResponse ToHttpApiRequestTooLargeResponse(ApiGatewayEmulatorMode emulatorMode)
+    {
+        if (emulatorMode == ApiGatewayEmulatorMode.Rest)
+        {
+            return new APIGatewayProxyResponse
+            {
+                StatusCode = 413,
+                Body = "{\"message\":\"Request Too Long\"}",
+                Headers = new Dictionary<string, string>
+                {
+                    { "Content-Type", "application/json" }
+                },
+                IsBase64Encoded = false
+            };
+        }
+        if (emulatorMode == ApiGatewayEmulatorMode.HttpV1)
+        {
+            return new APIGatewayProxyResponse
+            {
+                StatusCode = 413,
+                Body = "{\"message\":\"Request Entity Too Large\"}",
+                Headers = new Dictionary<string, string>
+                {
+                    { "Content-Type", "application/json" }
+                },
+                IsBase64Encoded = false
+            };
+        }
+        throw new ArgumentException($"Unsupported API Gateway emulator mode: {emulatorMode}. Only Rest and HttpV1 modes are supported.");
+    }
+
     /// <summary>
     /// Converts an Amazon Lambda InvokeResponse to an APIGatewayHttpApiV2ProxyResponse.
     /// </summary>
@@ -209,4 +257,25 @@ public static APIGatewayHttpApiV2ProxyResponse ToHttpApiV2ErrorResponse()
         };
     }
 
+    /// <summary>
+    /// Creates a standard HTTP API v2 response for a "Request Entity Too Large" (413) error.
+    /// </summary>
+    /// <returns>An APIGatewayHttpApiV2ProxyResponse configured with:
+    /// - Status code 413
+    /// - JSON error message
+    /// - Content-Type header set to application/json
+    /// </returns>
+    public static APIGatewayHttpApiV2ProxyResponse ToHttpApiV2RequestTooLargeResponse()
+    {
+        return new APIGatewayHttpApiV2ProxyResponse
+        {
+            StatusCode = 413,
+            Body = "{\"message\":\"Request Entity Too Large\"}",
+            Headers = new Dictionary<string, string>
+            {
+                { "Content-Type", "application/json" }
+            },
+            IsBase64Encoded = false
+        };
+    }
 }

Tools/LambdaTestTool-v2/src/Amazon.Lambda.TestTool/Models/LambdaOptions.cs

@@ -0,0 +1,18 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+namespace Amazon.Lambda.TestTool.Models;
+
+/// <summary>
+/// Configuration options for invoking lambda functions.
+/// </summary>
+public class LambdaOptions
+{
+    /// <summary>
+    /// Gets or sets the endpoint URL for Lambda function invocations.
+    /// </summary>
+    /// <value>
+    /// A string containing the endpoint URL. Defaults to an empty string.
+    /// </value>
+    public string Endpoint { get; set; } = string.Empty;
+}

Tools/LambdaTestTool-v2/src/Amazon.Lambda.TestTool/Processes/ApiGatewayEmulatorProcess.cs

@@ -52,6 +52,7 @@ public static ApiGatewayEmulatorProcess Startup(RunCommandSettings settings, Can
         Utils.ConfigureWebApplicationBuilder(builder);
 
         builder.Services.AddApiGatewayEmulatorServices();
+        builder.Services.AddSingleton<ILambdaClient, LambdaClient>();
 
         var serviceUrl = $"http://{settings.LambdaEmulatorHost}:{settings.ApiGatewayEmulatorPort}";
         builder.WebHost.UseUrls(serviceUrl);
@@ -68,7 +69,7 @@ public static ApiGatewayEmulatorProcess Startup(RunCommandSettings settings, Can
             app.Logger.LogInformation("The API Gateway Emulator is available at: {ServiceUrl}", serviceUrl);
         });
 
-        app.Map("/{**catchAll}", async (HttpContext context, IApiGatewayRouteConfigService routeConfigService) =>
+        app.Map("/{**catchAll}", async (HttpContext context, IApiGatewayRouteConfigService routeConfigService, ILambdaClient lambdaClient) =>
         {
             var routeConfig = routeConfigService.GetRouteConfig(context.Request.Method, context.Request.Path);
             if (routeConfig == null)
@@ -101,38 +102,56 @@ public static ApiGatewayEmulatorProcess Startup(RunCommandSettings settings, Can
                 PayloadStream = lambdaRequestStream
             };
 
-            using var lambdaClient = CreateLambdaServiceClient(routeConfig, settings);
-            var response =  await lambdaClient.InvokeAsync(invokeRequest);
-
-            if (response.FunctionError == null) // response is successful
+            try
             {
-                if (settings.ApiGatewayEmulatorMode.Equals(ApiGatewayEmulatorMode.HttpV2))
+                var endpoint = routeConfig.Endpoint ?? $"http://{settings.LambdaEmulatorHost}:{settings.LambdaEmulatorPort}";
+                var response = await lambdaClient.InvokeAsync(invokeRequest, endpoint);
+
+                if (response.FunctionError == null) // response is successful
                 {
-                    var lambdaResponse = response.ToApiGatewayHttpApiV2ProxyResponse();
-                    await lambdaResponse.ToHttpResponseAsync(context);
+                    if (settings.ApiGatewayEmulatorMode.Equals(ApiGatewayEmulatorMode.HttpV2))
+                    {
+                        var lambdaResponse = response.ToApiGatewayHttpApiV2ProxyResponse();
+                        await lambdaResponse.ToHttpResponseAsync(context);
+                    }
+                    else
+                    {
+                        var lambdaResponse = response.ToApiGatewayProxyResponse(settings.ApiGatewayEmulatorMode.Value);
+                        await lambdaResponse.ToHttpResponseAsync(context, settings.ApiGatewayEmulatorMode.Value);
+                    }
                 }
                 else
                 {
-                    var lambdaResponse = response.ToApiGatewayProxyResponse(settings.ApiGatewayEmulatorMode.Value);
-                    await lambdaResponse.ToHttpResponseAsync(context, settings.ApiGatewayEmulatorMode.Value);
+                    // For errors that happen within the function they still come back as 200 status code (they dont throw exception) but have FunctionError populated.
+                    // Api gateway just displays them as an internal server error, so we convert them to the correct error response here.
+                    if (settings.ApiGatewayEmulatorMode.Equals(ApiGatewayEmulatorMode.HttpV2))
+                    {
+                        var lambdaResponse = InvokeResponseExtensions.ToHttpApiV2ErrorResponse();
+                        await lambdaResponse.ToHttpResponseAsync(context);
+                    }
+                    else
+                    {
+                        var lambdaResponse = InvokeResponseExtensions.ToApiGatewayErrorResponse(settings.ApiGatewayEmulatorMode.Value);
+                        await lambdaResponse.ToHttpResponseAsync(context, settings.ApiGatewayEmulatorMode.Value);
+                    }
                 }
             }
-            else
+            catch (AmazonLambdaException e)
             {
-                // For function errors, api gateway just displays them as an internal server error, so we convert them to the correct error response here.
-
-                if (settings.ApiGatewayEmulatorMode.Equals(ApiGatewayEmulatorMode.HttpV2))
+                if (e.ErrorCode == Exceptions.RequestEntityTooLargeException)
                 {
-                    var lambdaResponse = InvokeResponseExtensions.ToHttpApiV2ErrorResponse();
-                    await lambdaResponse.ToHttpResponseAsync(context);
-                }
-                else
-                {
-                    var lambdaResponse = InvokeResponseExtensions.ToApiGatewayErrorResponse(settings.ApiGatewayEmulatorMode.Value);
-                    await lambdaResponse.ToHttpResponseAsync(context, settings.ApiGatewayEmulatorMode.Value);
+                    if (settings.ApiGatewayEmulatorMode.Equals(ApiGatewayEmulatorMode.HttpV2))
+                    {
+                        var lambdaResponse = InvokeResponseExtensions.ToHttpApiV2RequestTooLargeResponse();
+                        await lambdaResponse.ToHttpResponseAsync(context);
+                    }
+                    else
+                    {
+                        var lambdaResponse = InvokeResponseExtensions.ToHttpApiRequestTooLargeResponse(settings.ApiGatewayEmulatorMode.Value);
+                        await lambdaResponse.ToHttpResponseAsync(context, settings.ApiGatewayEmulatorMode.Value);
+                    }
                 }
             }
-
         });
 
         var runTask = app.RunAsync(cancellationToken);
@@ -144,30 +163,4 @@ public static ApiGatewayEmulatorProcess Startup(RunCommandSettings settings, Can
             ServiceUrl = serviceUrl
         };
     }
-
-    /// <summary>
-    /// Creates an Amazon Lambda service client with the specified configuration.
-    /// </summary>
-    /// <param name="routeConfig">The API Gateway route configuration containing the endpoint information.
-    /// If the endpoint is specified in routeConfig, it will be used as the service URL.</param>
-    /// <param name="settings">The run command settings containing host and port information.
-    /// If routeConfig endpoint is null, the service URL will be constructed using settings.Host and settings.Port.</param>
-    /// <returns>An instance of IAmazonLambda configured with the specified endpoint and credentials.</returns>
-    /// <remarks>
-    /// The function uses hard-coded AWS credentials ("accessKey", "secretKey") for authentication since they are not actually being used.
-    /// The service URL is determined by either:
-    /// - Using routeConfig.Endpoint if it's not null
-    /// - Combining settings.Host and settings.Port if routeConfig.Endpoint is null
-    /// </remarks>
-    private static IAmazonLambda CreateLambdaServiceClient(ApiGatewayRouteConfig routeConfig, RunCommandSettings settings)
-    {
-        var endpoint = routeConfig.Endpoint ?? $"http://{settings.LambdaEmulatorHost}:{settings.LambdaEmulatorPort}";
-
-        var lambdaConfig = new AmazonLambdaConfig
-        {
-            ServiceURL = endpoint
-        };
-
-        return new AmazonLambdaClient(new Amazon.Runtime.BasicAWSCredentials("accessKey", "secretKey"), lambdaConfig);
-    }
 }