MET-4188 add GetOptions extension to IConfiguration

Author: agentschmitt

README.md

@@ -1,4 +1,4 @@
-# Samhammer.Options
+# Samhammer.Options
 
 ## Usage
 
@@ -93,6 +93,29 @@ appsettings.json
 }
 ```
 
+### How to get options from IConfiguration ##
+It is possible to bind options directly from IConfiguration. \
+This can be helpful in Program.cs to use typed Options there, even before they are registered in IOC.
+
+```csharp
+var builder = WebApplication.CreateBuilder(args);
+var key = builder.Configuration.GetOptions<ExampleOptions>().MyKey;
+```
+
+```csharp
+[Option]
+public class ExampleOptions{
+    public string MyKey { get; set; }
+}
+```
+
+appsettings.json
+```json
+"ExampleOptions": {
+  "MyKey": "1234"
+}
+```
+
 ## Configuration
 Starting with version 3.1.5 all customizations needs to be done with the options action.
 

src/Samhammer.Options.Test/ConfigurationExtensionsTest.cs

@@ -0,0 +1,83 @@
+using System.Collections.Generic;
+using FluentAssertions;
+using Microsoft.Extensions.Configuration;
+using Samhammer.Options.Abstractions;
+using Xunit;
+
+namespace Samhammer.Options.Test
+{
+    public class ConfigurationExtensionsTest
+    {
+        private readonly ConfigurationBuilder configurationBuilder;
+
+        private readonly List<KeyValuePair<string, string>> configurationValues;
+
+        private IConfiguration Configuration => configurationBuilder.Build();
+
+        public ConfigurationExtensionsTest()
+        {
+            configurationBuilder = new ConfigurationBuilder();
+            configurationValues = new List<KeyValuePair<string, string>>();
+            configurationBuilder.AddInMemoryCollection(configurationValues);
+        }
+
+        [Fact]
+        public void GetOptions_FromConfiguration_WithAttribute()
+        {
+            // arrange
+            configurationValues.Add(new KeyValuePair<string, string>("TestOptions:Url", "http://localhost"));
+
+            // act
+            var options = Configuration.GetOptions<TestOptionsWithAttribute>();
+
+            // assert
+            var expectedOptions = new TestOptionsWithAttribute { Url = "http://localhost" };
+            options.Should().BeEquivalentTo(expectedOptions);
+        }
+
+        [Fact]
+        public void GetOptions_FromConfiguration_WithRootAttribute()
+        {
+            // arrange
+            configurationValues.Add(new KeyValuePair<string, string>("Url", "http://localhost"));
+
+            // act
+            var options = Configuration.GetOptions<TestOptionsWithRootAttribute>();
+
+            // assert
+            var expectedOptions = new TestOptionsWithRootAttribute { Url = "http://localhost" };
+            options.Should().BeEquivalentTo(expectedOptions);
+        }
+
+        [Fact]
+        public void GetOption_FromConfiguration_WithoutAttribute()
+        {
+            // arrange
+            configurationValues.Add(new KeyValuePair<string, string>("TestOptions:Url", "http://localhost"));
+
+            // act
+            var options = Configuration.GetOptions<TestOptions>();
+
+            // assert
+            var expectedOptions = new TestOptions { Url = "http://localhost" };
+            options.Should().BeEquivalentTo(expectedOptions);
+        }
+
+        [Option(sectionName: "TestOptions")]
+        private class TestOptionsWithAttribute
+        {
+            public string Url { get; set; }
+        }
+
+        [Option(FromRootSection = true)]
+        private class TestOptionsWithRootAttribute
+        {
+            public string Url { get; set; }
+        }
+
+        private class TestOptions
+        {
+            public string Url { get; set; }
+        }
+    }
+}

src/Samhammer.Options.sln.DotSettings

@@ -6,8 +6,12 @@
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=LocalConstants/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="AaBb" /&gt;</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=PrivateInstanceFields/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="aaBb" /&gt;</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=PrivateStaticFields/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="aaBb" /&gt;</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/UserRules/=4a98fdf6_002D7d98_002D4f5a_002Dafeb_002Dea44ad98c70c/@EntryIndexedValue">&lt;Policy&gt;&lt;Descriptor Staticness="Instance" AccessRightKinds="Private" Description="Instance fields (private)"&gt;&lt;ElementKinds&gt;&lt;Kind Name="FIELD" /&gt;&lt;Kind Name="READONLY_FIELD" /&gt;&lt;/ElementKinds&gt;&lt;/Descriptor&gt;&lt;Policy Inspect="True" WarnAboutPrefixesAndSuffixes="False" Prefix="" Suffix="" Style="aaBb" /&gt;&lt;/Policy&gt;</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/UserRules/=a4f433b8_002Dabcd_002D4e55_002Da08f_002D82e78cef0f0c/@EntryIndexedValue">&lt;Policy&gt;&lt;Descriptor Staticness="Any" AccessRightKinds="Any" Description="Local constants"&gt;&lt;ElementKinds&gt;&lt;Kind Name="LOCAL_CONSTANT" /&gt;&lt;/ElementKinds&gt;&lt;/Descriptor&gt;&lt;Policy Inspect="True" WarnAboutPrefixesAndSuffixes="False" Prefix="" Suffix="" Style="AaBb" /&gt;&lt;/Policy&gt;</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/UserRules/=f9fce829_002De6f4_002D4cb2_002D80f1_002D5497c44f51df/@EntryIndexedValue">&lt;Policy&gt;&lt;Descriptor Staticness="Static" AccessRightKinds="Private" Description="Static fields (private)"&gt;&lt;ElementKinds&gt;&lt;Kind Name="FIELD" /&gt;&lt;/ElementKinds&gt;&lt;/Descriptor&gt;&lt;Policy Inspect="True" WarnAboutPrefixesAndSuffixes="False" Prefix="" Suffix="" Style="aaBb" /&gt;&lt;/Policy&gt;</s:String>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpKeepExistingMigration/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpPlaceEmbeddedOnSameLineMigration/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpUseContinuousIndentInsideBracesMigration/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EMigrateBlankLinesAroundFieldToBlankLinesAroundProperty/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EPredefinedNamingRulesToUserRulesUpgrade/@EntryIndexedValue">True</s:Boolean>
 </wpf:ResourceDictionary>

src/Samhammer.Options/ConfigurationExtensions.cs

@@ -0,0 +1,23 @@
+using System.Linq;
+using Microsoft.Extensions.Configuration;
+using Samhammer.Options.Abstractions;
+using Samhammer.Options.Utils;
+
+namespace Samhammer.Options
+{
+    public static class ConfigurationExtensions
+    {
+        public static T GetOptions<T>(this IConfiguration configuration) where T : new()
+        {
+            var optionType = typeof(T);
+            var attributes = ReflectionUtils.GetAttributesOfType<OptionAttribute>(optionType).ToList();
+
+            var section = attributes.Count > 0
+                ? ConfigurationResolver.GetSection(configuration, optionType, attributes.First())
+                : ConfigurationResolver.GetSection(configuration, optionType);
+
+            var option = section.Get<T>();
+            return option != null ? option : new T();
+        }
+    }
+}

src/Samhammer.Options/ConfigurationResolver.cs

@@ -0,0 +1,38 @@
+using System;
+using Microsoft.Extensions.Configuration;
+using Samhammer.Options.Abstractions;
+
+namespace Samhammer.Options
+{
+    internal static class ConfigurationResolver
+    {
+        internal static IConfiguration GetSection(IConfiguration configuration, Type optionType, OptionAttribute optionAttribute)
+        {
+            var sectionName = GetSectionName(optionType, optionAttribute);
+            return optionAttribute.FromRootSection ? configuration : configuration.GetSection(sectionName);
+        }
+
+        internal static IConfiguration GetSection(IConfiguration configuration, Type optionType)
+        {
+            var sectionName = GetSectionName(optionType);
+            return configuration.GetSection(sectionName);
+        }
+
+        private static string GetSectionName(Type optionType, OptionAttribute attribute)
+        {
+            var key = attribute.SectionName;
+
+            if (string.IsNullOrWhiteSpace(key))
+            {
+                key = optionType.Name;
+            }
+
+            return key;
+        }
+
+        private static string GetSectionName(Type optionType)
+        {
+            return optionType.Name;
+        }
+    }
+}

src/Samhammer.Options/OptionsResolver.cs

@@ -51,25 +51,12 @@ public void ResolveConfigurations(IServiceCollection services)
 
         private void ResolveConfiguration(IServiceCollection services, Type optionType, OptionAttribute optionAttribute)
         {
-            var sectionName = GetSectionName(optionType, optionAttribute);
-            var section = optionAttribute.FromRootSection ? Configuration : Configuration.GetSection(sectionName);
+            var section = ConfigurationResolver.GetSection(Configuration, optionType, optionAttribute);
 
             var genericMethod = AddOptionMethod.MakeGenericMethod(optionType);
             genericMethod.Invoke(this, new object[] { services, section, optionAttribute.IocName });
         }
 
-        private string GetSectionName(Type optionType, OptionAttribute attribute)
-        {
-            var key = attribute.SectionName;
-
-            if (string.IsNullOrWhiteSpace(key))
-            {
-                key = optionType.Name;
-            }
-
-            return key;
-        }
-
         private void AddOption<T>(IServiceCollection services, IConfiguration section, string iocOptionName = null) where T : class
         {
             services.Configure<T>(