feat: extend support for ConfigureAll OptionsBinding

Author: davidkallesen

CLAUDE.md

@@ -300,6 +300,7 @@ services.AddDependencyRegistrationsFromDomain(
 - Supports validation: `ValidateDataAnnotations`, `ValidateOnStart`, `ErrorOnMissingKeys` (fail-fast for missing sections), Custom validators (`IValidateOptions<T>`)
 - **Configuration change callbacks**: Auto-generated IHostedService for OnChange notifications with Monitor lifetime - perfect for feature flags and runtime configuration updates
 - **Post-configuration support**: `PostConfigure` callbacks for normalizing/transforming values after binding (e.g., path normalization, URL lowercase)
+- **ConfigureAll support**: Set common default values for all named options instances before individual binding with `ConfigureAll` callbacks (e.g., baseline retry/timeout settings)
 - **Named options support**: Multiple configurations of the same options type with different names (e.g., Primary/Secondary email servers)
 - **Nested subsection binding**: Automatic binding of complex properties to configuration subsections (e.g., `StorageOptions.Database.Retry` → `"Storage:Database:Retry"`) - supported out-of-the-box by Microsoft's `.Bind()` method
 - Supports lifetime selection: Singleton (IOptions), Scoped (IOptionsSnapshot), Monitor (IOptionsMonitor)
@@ -429,6 +430,31 @@ public partial class StorageOptions
 services.AddOptions<StorageOptions>()
     .Bind(configuration.GetSection("Storage"))
     .PostConfigure(options => StorageOptions.NormalizePaths(options));
+
+// Input with ConfigureAll (set defaults for all named instances):
+[OptionsBinding("Email:Primary", Name = "Primary", ConfigureAll = nameof(SetDefaults))]
+[OptionsBinding("Email:Secondary", Name = "Secondary")]
+[OptionsBinding("Email:Fallback", Name = "Fallback")]
+public partial class EmailOptions
+{
+    public string SmtpServer { get; set; } = string.Empty;
+    public int Port { get; set; } = 587;
+    public int MaxRetries { get; set; }
+    public int TimeoutSeconds { get; set; } = 30;
+
+    internal static void SetDefaults(EmailOptions options)
+    {
+        options.MaxRetries = 3;
+        options.TimeoutSeconds = 30;
+        options.Port = 587;
+    }
+}
+
+// Output with ConfigureAll (runs BEFORE individual configurations):
+services.ConfigureAll<EmailOptions>(options => EmailOptions.SetDefaults(options));
+services.Configure<EmailOptions>("Primary", configuration.GetSection("Email:Primary"));
+services.Configure<EmailOptions>("Secondary", configuration.GetSection("Email:Secondary"));
+services.Configure<EmailOptions>("Fallback", configuration.GetSection("Email:Fallback"));
 ```
 
 **Smart Naming:**
@@ -466,6 +492,9 @@ services.AddOptionsFromDomain(configuration, "DataAccess", "Infrastructure");
 - `ATCOPT008` - PostConfigure not supported with named options (Error)
 - `ATCOPT009` - PostConfigure callback method not found (Error)
 - `ATCOPT010` - PostConfigure callback has invalid signature (Error)
+- `ATCOPT011` - ConfigureAll requires multiple named options (Error)
+- `ATCOPT012` - ConfigureAll callback method not found (Error)
+- `ATCOPT013` - ConfigureAll callback has invalid signature (Error)
 
 ### MappingGenerator
 

docs/OptionsBindingGenerators-FeatureRoadmap.md

@@ -79,7 +79,7 @@ This roadmap is based on comprehensive analysis of:
 | ✅ | [Error on Missing Configuration Keys](#4-error-on-missing-configuration-keys) | 🔴 High |
 | ✅ | [Configuration Change Callbacks](#5-configuration-change-callbacks) | 🟡 Medium |
 | ✅ | [Bind Configuration Subsections to Properties](#6-bind-configuration-subsections-to-properties) | 🟡 Medium |
-| ❌ | [ConfigureAll Support](#7-configureall-support) | 🟢 Low-Medium |
+| ✅ | [ConfigureAll Support](#7-configureall-support) | 🟢 Low-Medium |
 | ❌ | [Options Snapshots for Specific Sections](#8-options-snapshots-for-specific-sections) | 🟢 Low-Medium |
 | ❌ | [Compile-Time Section Name Validation](#9-compile-time-section-name-validation) | 🟡 Medium |
 | ❌ | [Auto-Generate Options Classes from appsettings.json](#10-auto-generate-options-classes-from-appsettingsjson) | 🟢 Low |
@@ -599,28 +599,66 @@ public class DatabaseRetryPolicy
 ### 7. ConfigureAll Support
 
 **Priority**: 🟢 **Low-Medium**
-**Status**: ❌ Not Implemented
+**Status**: ✅ **Implemented**
 
-**Description**: Support configuring all named instances of an options type at once (e.g., setting defaults).
+**Description**: Support configuring all named instances of an options type at once, allowing you to set common defaults that apply to all named configurations before individual settings override them.
 
 **Example**:
 
 ```csharp
-// Configure defaults for ALL named DatabaseOptions instances
-services.ConfigureAll<DatabaseOptions>(options =>
+[OptionsBinding("Email:Primary", Name = "Primary", ConfigureAll = nameof(SetDefaults))]
+[OptionsBinding("Email:Secondary", Name = "Secondary")]
+[OptionsBinding("Email:Fallback", Name = "Fallback")]
+public partial class EmailOptions
 {
-    options.MaxRetries = 3;  // Default for all instances
-    options.CommandTimeout = TimeSpan.FromSeconds(30);
-});
+    public string SmtpServer { get; set; } = string.Empty;
+    public int Port { get; set; } = 587;
+    public int MaxRetries { get; set; }
+    public int TimeoutSeconds { get; set; } = 30;
 
-// Named instances override specific values
-services.Configure<DatabaseOptions>("Primary", config.GetSection("Databases:Primary"));
+    internal static void SetDefaults(EmailOptions options)
+    {
+        // Set common defaults for ALL email configurations
+        options.MaxRetries = 3;
+        options.TimeoutSeconds = 30;
+        options.Port = 587;
+    }
+}
 ```
 
-**Implementation Notes**:
+**Generated Code**:
+
+```csharp
+// Configure defaults for ALL named instances FIRST
+services.ConfigureAll<EmailOptions>(options => EmailOptions.SetDefaults(options));
+
+// Then configure individual instances (can override defaults)
+services.Configure<EmailOptions>("Primary", config.GetSection("Email:Primary"));
+services.Configure<EmailOptions>("Secondary", config.GetSection("Email:Secondary"));
+services.Configure<EmailOptions>("Fallback", config.GetSection("Email:Fallback"));
+```
+
+**Implementation Details**:
+
+- ✅ **Requires multiple named instances** - Cannot be used with single unnamed instance (compile-time error)
+- ✅ **Method signature validation** - Must be `static void MethodName(TOptions options)`
+- ✅ **Execution order** - ConfigureAll runs BEFORE individual Configure calls
+- ✅ **Flexible placement** - Can be specified on any one of the `[OptionsBinding]` attributes
+- ✅ **Override support** - Individual configurations can override defaults set by ConfigureAll
+- ✅ **Compile-time safety** - Diagnostics ATCOPT011-013 validate usage and method signature
+
+**Use Cases**:
+
+- **Baseline settings**: Set common retry, timeout, or connection defaults across all database connections
+- **Feature flags**: Enable/disable common features for all tenant configurations
+- **Security defaults**: Apply consistent security settings across all API client configurations
+- **Notification channels**: Set common rate limits and retry policies for all notification providers
+
+**Testing**:
 
-- Generate `ConfigureAll<T>()` call when multiple named instances exist
-- Useful for setting defaults across all instances
+- ✅ 14 comprehensive unit tests covering all scenarios
+- ✅ Sample project: EmailOptions demonstrates default retry/timeout settings
+- ✅ PetStore.Api sample: NotificationOptions demonstrates common defaults for Email/SMS/Push channels
 
 ---
 

docs/OptionsBindingGenerators-Samples.md

@@ -697,9 +697,9 @@ The generator enforces these rules at compile time:
 
 ## 📛 Named Options Support
 
-**Named Options** allow multiple configurations of the same options type with different names - perfect for fallback scenarios, multi-tenant applications, or multi-region deployments.
+**Named Options** allow multiple configurations of the same options type with different names - perfect for fallback scenarios, multi-tenant applications, or multi-region deployments. You can also use **ConfigureAll** to set common defaults for all named instances.
 
-### 🎯 Example: Email Server Fallback
+### 🎯 Example: Email Server Fallback with ConfigureAll
 
 **Options Class:**
 
@@ -708,7 +708,7 @@ using Atc.SourceGenerators.Annotations;
 
 namespace Atc.SourceGenerators.OptionsBinding.Options;
 
-[OptionsBinding("Email:Primary", Name = "Primary")]
+[OptionsBinding("Email:Primary", Name = "Primary", ConfigureAll = nameof(SetDefaults))]
 [OptionsBinding("Email:Secondary", Name = "Secondary")]
 [OptionsBinding("Email:Fallback", Name = "Fallback")]
 public partial class EmailOptions
@@ -718,6 +718,16 @@ public partial class EmailOptions
     public bool UseSsl { get; set; } = true;
     public string FromAddress { get; set; } = string.Empty;
     public int TimeoutSeconds { get; set; } = 30;
+    public int MaxRetries { get; set; }
+
+    internal static void SetDefaults(EmailOptions options)
+    {
+        // Set common defaults for ALL email configurations
+        options.UseSsl = true;
+        options.TimeoutSeconds = 30;
+        options.MaxRetries = 3;
+        options.Port = 587;
+    }
 }
 ```
 
@@ -763,6 +773,9 @@ public static class ServiceCollectionExtensions
         this IServiceCollection services,
         IConfiguration configuration)
     {
+        // Configure defaults for ALL named instances of EmailOptions
+        services.ConfigureAll<EmailOptions>(options => EmailOptions.SetDefaults(options));
+
         // Configure EmailOptions (Named: "Primary")
         services.Configure<EmailOptions>("Primary", configuration.GetSection("Email:Primary"));
 

docs/OptionsBindingGenerators.md

@@ -746,6 +746,7 @@ Console.WriteLine($"Other interval: {otherOptions.Value.RepeatIntervalInSeconds}
 - **🚨 Error on missing keys** - Fail-fast validation when configuration sections are missing (`ErrorOnMissingKeys`) to catch deployment issues at startup
 - **🔔 Configuration change callbacks** - Automatically respond to configuration changes at runtime with `OnChange` callbacks (requires Monitor lifetime)
 - **🔧 Post-configuration support** - Normalize or transform values after binding with `PostConfigure` callbacks (e.g., ensure paths have trailing slashes, lowercase URLs)
+- **🎛️ ConfigureAll support** - Set common default values for all named options instances before individual binding with `ConfigureAll` callbacks (e.g., baseline retry/timeout settings)
 - **📛 Named options** - Multiple configurations of the same options type with different names (e.g., Primary/Secondary email servers)
 - **🎯 Explicit section paths** - Support for nested sections like `"App:Database"` or `"Services:Email"`
 - **📂 Nested subsection binding** - Automatically bind complex properties to configuration subsections (e.g., `StorageOptions.Database.Retry` → `"Storage:Database:Retry"`)
@@ -1478,6 +1479,141 @@ The generator performs compile-time validation of PostConfigure callbacks:
 
 ---
 
+### 🎛️ ConfigureAll Support
+
+Set default values for **all named options instances** before individual configuration binding. This feature is perfect for establishing common baseline settings across multiple named configurations that can then be selectively overridden.
+
+**Requirements:**
+- Requires multiple named instances (at least 2)
+- Callback method must have signature: `static void MethodName(TOptions options)`
+- Runs **before** individual `Configure()` calls
+
+**Basic Example:**
+
+```csharp
+[OptionsBinding("Email:Primary", Name = "Primary", ConfigureAll = nameof(SetDefaults))]
+[OptionsBinding("Email:Secondary", Name = "Secondary")]
+[OptionsBinding("Email:Fallback", Name = "Fallback")]
+public partial class EmailOptions
+{
+    public string SmtpServer { get; set; } = string.Empty;
+    public int Port { get; set; } = 587;
+    public bool UseSsl { get; set; } = true;
+    public int TimeoutSeconds { get; set; } = 30;
+    public int MaxRetries { get; set; }
+
+    internal static void SetDefaults(EmailOptions options)
+    {
+        // Set common defaults for ALL email configurations
+        options.UseSsl = true;
+        options.TimeoutSeconds = 30;
+        options.MaxRetries = 3;
+        options.Port = 587;
+    }
+}
+```
+
+**Generated Code:**
+
+The generator automatically calls `.ConfigureAll()` **before** individual configurations:
+
+```csharp
+// Configure defaults for ALL named instances FIRST
+services.ConfigureAll<EmailOptions>(options => EmailOptions.SetDefaults(options));
+
+// Then configure individual instances (can override defaults)
+services.Configure<EmailOptions>("Primary", configuration.GetSection("Email:Primary"));
+services.Configure<EmailOptions>("Secondary", configuration.GetSection("Email:Secondary"));
+services.Configure<EmailOptions>("Fallback", configuration.GetSection("Email:Fallback"));
+```
+
+**Usage Scenarios:**
+
+```csharp
+// Notification channels - common defaults for all channels
+[OptionsBinding("Notifications:Email", Name = "Email", ConfigureAll = nameof(SetCommonDefaults))]
+[OptionsBinding("Notifications:SMS", Name = "SMS")]
+[OptionsBinding("Notifications:Push", Name = "Push")]
+public partial class NotificationOptions
+{
+    public bool Enabled { get; set; }
+    public int TimeoutSeconds { get; set; } = 30;
+    public int MaxRetries { get; set; } = 3;
+    public int RateLimitPerMinute { get; set; }
+
+    internal static void SetCommonDefaults(NotificationOptions options)
+    {
+        // All notification channels start with these defaults
+        options.TimeoutSeconds = 30;
+        options.MaxRetries = 3;
+        options.RateLimitPerMinute = 60;
+        options.Enabled = true;
+    }
+}
+
+// Database connections - common retry and timeout defaults
+[OptionsBinding("Database:Primary", Name = "Primary", ConfigureAll = nameof(SetConnectionDefaults))]
+[OptionsBinding("Database:ReadReplica", Name = "ReadReplica")]
+[OptionsBinding("Database:Analytics", Name = "Analytics")]
+public partial class DatabaseConnectionOptions
+{
+    public string ConnectionString { get; set; } = string.Empty;
+    public int MaxRetries { get; set; }
+    public int CommandTimeoutSeconds { get; set; }
+    public bool EnableRetry { get; set; }
+
+    internal static void SetConnectionDefaults(DatabaseConnectionOptions options)
+    {
+        // All database connections start with these baseline settings
+        options.MaxRetries = 3;
+        options.CommandTimeoutSeconds = 30;
+        options.EnableRetry = true;
+    }
+}
+```
+
+**Validation Errors:**
+
+The generator performs compile-time validation of ConfigureAll callbacks:
+
+- **ATCOPT011**: ConfigureAll requires multiple named options
+  ```csharp
+  // Error: ConfigureAll needs at least 2 named instances
+  [OptionsBinding("Settings", Name = "Default", ConfigureAll = nameof(SetDefaults))]
+  public partial class Settings { }
+  ```
+
+- **ATCOPT012**: ConfigureAll callback method not found
+  ```csharp
+  // Error: Method 'SetDefaults' does not exist
+  [OptionsBinding("Email", Name = "Primary", ConfigureAll = "SetDefaults")]
+  [OptionsBinding("Email", Name = "Secondary")]
+  public partial class EmailOptions { }
+  ```
+
+- **ATCOPT013**: ConfigureAll callback method has invalid signature
+  ```csharp
+  // Error: Must be static void with (TOptions) parameter
+  [OptionsBinding("Email", Name = "Primary", ConfigureAll = nameof(Configure))]
+  [OptionsBinding("Email", Name = "Secondary")]
+  public partial class EmailOptions
+  {
+      private void Configure() { }  // Wrong: not static, missing parameter
+  }
+  ```
+
+**Important Notes:**
+
+- ConfigureAll runs **before** individual named instance configurations
+- Individual configurations can override defaults set by ConfigureAll
+- Callback method can be `internal` or `public` (not `private`)
+- **Requires multiple named instances** - cannot be used with single unnamed instance
+- Perfect for establishing baseline settings across multiple configurations
+- Order of execution: ConfigureAll → Configure("Name1") → Configure("Name2") → ...
+- Can be specified on any one of the `[OptionsBinding]` attributes (only processed once)
+
+---
+
 ## 🔧 How It Works
 
 ### 1️⃣ Attribute Detection
@@ -2052,6 +2188,12 @@ See [Post-Configuration Support](#-post-configuration-support) section for detai
 
 ---
 
+### ❌ ATCOPT011-013: ConfigureAll Callback Diagnostics
+
+See [ConfigureAll Support](#️-configureall-support) section for details.
+
+---
+
 ## 🚀 Native AOT Compatibility
 
 The Options Binding Generator is **fully compatible with Native AOT** compilation, producing code that meets all AOT requirements:

sample/Atc.SourceGenerators.OptionsBinding/Options/EmailOptions.cs

@@ -4,8 +4,9 @@ namespace Atc.SourceGenerators.OptionsBinding.Options;
 /// Email server options with support for multiple named configurations.
 /// This class demonstrates the Named Options feature which allows the same options type
 /// to be bound to different configuration sections using different names.
+/// It also demonstrates the ConfigureAll feature which sets default values for ALL named instances.
 /// </summary>
-[OptionsBinding("Email:Primary", Name = "Primary")]
+[OptionsBinding("Email:Primary", Name = "Primary", ConfigureAll = nameof(SetDefaults))]
 [OptionsBinding("Email:Secondary", Name = "Secondary")]
 [OptionsBinding("Email:Fallback", Name = "Fallback")]
 public partial class EmailOptions
@@ -34,4 +35,23 @@ public partial class EmailOptions
     /// Gets or sets the timeout in seconds.
     /// </summary>
     public int TimeoutSeconds { get; set; } = 30;
+
+    /// <summary>
+    /// Gets or sets the maximum number of retry attempts.
+    /// </summary>
+    public int MaxRetries { get; set; }
+
+    /// <summary>
+    /// Configures default values for ALL email instances.
+    /// This method runs BEFORE individual configurations, allowing defaults to be set
+    /// that can be overridden by specific configuration sections.
+    /// </summary>
+    internal static void SetDefaults(EmailOptions options)
+    {
+        // Set defaults for all email configurations
+        options.UseSsl = true;
+        options.TimeoutSeconds = 30;
+        options.MaxRetries = 3;
+        options.Port = 587;
+    }
 }