Feature/get debug view value processing (#60391)

* Added parameter for processing the value of the configuration e.g. for obfuscation

* Rename

* Extension methods separated

* After review suggestion changes

* Documentation update

* Build fixes

* Documentation for ConfigurationDebugViewContext added

* Nullable string error fix

* Changed to nullable string

* PR fixes

* Definition fix

* Missing definition

* Added getters to the definition

* Update src/libraries/Microsoft.Extensions.Configuration.Abstractions/src/ConfigurationRootExtensions.cs

Co-authored-by: Santiago Fernandez Madero <[email protected]>

* Tests added

* Update src/libraries/Microsoft.Extensions.Configuration.Abstractions/src/ConfigurationDebugViewContext.cs

Docs update

Co-authored-by: Eric Erhardt <[email protected]>

* Update src/libraries/Microsoft.Extensions.Configuration.Abstractions/src/ConfigurationDebugViewContext.cs

Docs updateDocs update

Co-authored-by: Eric Erhardt <[email protected]>

* Update src/libraries/Microsoft.Extensions.Configuration.Abstractions/src/ConfigurationDebugViewContext.cs

Docs update

Co-authored-by: Eric Erhardt <[email protected]>

* Update src/libraries/Microsoft.Extensions.Configuration.Abstractions/src/ConfigurationDebugViewContext.cs

Docs update

Co-authored-by: Eric Erhardt <[email protected]>

* Update src/libraries/Microsoft.Extensions.Configuration.Abstractions/src/ConfigurationRootExtensions.cs

Docs update

Co-authored-by: Eric Erhardt <[email protected]>

* Update src/libraries/Microsoft.Extensions.Configuration.Abstractions/src/ConfigurationDebugViewContext.cs

Docs update

Co-authored-by: Eric Erhardt <[email protected]>

Co-authored-by: Santiago Fernandez Madero <[email protected]>
Co-authored-by: Eric Erhardt <[email protected]>

src/libraries/Common/tests/Extensions/ConfigurationRootTest.cs

@@ -11,6 +11,8 @@ namespace Microsoft.Extensions.Configuration.Test
 {
  public class ConfigurationRootTest
  {
+ private const string SecretCover = "*****";
+
  [Fact]
  public void RootDisposesProviders()
  {
@@ -77,12 +79,56 @@ public void ChainedConfigurationIsDisposed(bool shouldDispose)
  Assert.Equal(shouldDispose, provider.IsDisposed);
  }
 
+ [Fact]
+ public void SecretsAreConcealed()
+ {
+ var provider = new SecretConfigurationProvider("secret", "secret-value");
+
+ var config = new ConfigurationRoot(new IConfigurationProvider[] {
+ provider
+ });
+
+ var debugView = config.GetDebugView(ProcessValue);
+
+ Assert.Contains(SecretCover, debugView);
+ }
+
+ [Fact]
+ public void NonSecretsAreNotConcealed()
+ {
+ var provider = new TestConfigurationProvider("foo", "foo-value");
+
+ var config = new ConfigurationRoot(new IConfigurationProvider[] {
+ provider
+ });
+
+ var debugView = config.GetDebugView(ProcessValue);
+
+ Assert.DoesNotContain(SecretCover, debugView);
+ }
+
+ private string ProcessValue(ConfigurationDebugViewContext context)
+ {
+ if (context.ConfigurationProvider.ToString() == nameof(SecretConfigurationProvider))
+ {
+ return SecretCover;
+ }
+
+ return context.Value;
+ }
+
  private class TestConfigurationProvider : ConfigurationProvider
  {
  public TestConfigurationProvider(string key, string value)
  => Data.Add(key, value);
  }
 
+ private class SecretConfigurationProvider : ConfigurationProvider
+ {
+ public SecretConfigurationProvider(string key, string value)
+ => Data.Add(key, value);
+ }
+
  private class DisposableTestConfigurationProvider : ConfigurationProvider, IDisposable
  {
  public bool IsDisposed { get; set; }

src/libraries/Microsoft.Extensions.Configuration.Abstractions/ref/Microsoft.Extensions.Configuration.Abstractions.cs

@@ -33,6 +33,15 @@ public static partial class ConfigurationPath
  public static partial class ConfigurationRootExtensions
  {
  public static string GetDebugView(this Microsoft.Extensions.Configuration.IConfigurationRoot root) { throw null; }
+ public static string GetDebugView(this IConfigurationRoot root, System.Func<ConfigurationDebugViewContext, string>? processValue) { throw null; }
+ }
+ public readonly partial struct ConfigurationDebugViewContext
+ {
+ public ConfigurationDebugViewContext(string path, string key, string? value, IConfigurationProvider configurationProvider) { throw null; }
+ public string Path { get; }
+ public string Key { get; }
+ public string? Value { get; }
+ public IConfigurationProvider ConfigurationProvider { get; }
  }
  public partial interface IConfiguration
  {

src/libraries/Microsoft.Extensions.Configuration.Abstractions/src/ConfigurationDebugViewContext.cs

@@ -0,0 +1,39 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.Extensions.Configuration
+{
+ /// <summary>
+ /// Provides the data about current item of the configuration.
+ /// </summary>
+ public readonly struct ConfigurationDebugViewContext
+ {
+ public ConfigurationDebugViewContext(string path, string key, string? value, IConfigurationProvider configurationProvider)
+ {
+ Path = path;
+ Key = key;
+ Value = value;
+ ConfigurationProvider = configurationProvider;
+ }
+
+ /// <summary>
+ /// Gets the path of the current item.
+ /// </summary>
+ public string Path { get; }
+
+ /// <summary>
+ /// Gets the key of the current item.
+ /// </summary>
+ public string Key { get; }
+
+ /// <summary>
+ /// Gets the value of the current item.
+ /// </summary>
+ public string? Value { get; }
+
+ /// <summary>
+ /// Gets the <see cref="IConfigurationProvider" /> that was used to get the value of the current item.
+ /// </summary>
+ public IConfigurationProvider ConfigurationProvider { get; }
+ }
+}

src/libraries/Microsoft.Extensions.Configuration.Abstractions/src/ConfigurationRootExtensions.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
@@ -17,6 +18,22 @@ public static class ConfigurationRootExtensions
  /// </summary>
  /// <returns> The debug view. </returns>
  public static string GetDebugView(this IConfigurationRoot root)
+ {
+ return GetDebugView(root, processValue: null);
+ }
+
+ /// <summary>
+ /// Generates a human-readable view of the configuration showing where each value came from.
+ /// </summary>
+ /// <param name="root">Configuration root</param>
+ /// <param name="processValue">
+ /// Function for processing the value e.g. hiding secrets
+ /// Parameters:
+ /// ConfigurationDebugViewContext: Context of the current configuration item
+ /// returns: A string value is used to assign as the Value of the configuration section
+ /// </param>
+ /// <returns> The debug view. </returns>
+ public static string GetDebugView(this IConfigurationRoot root, Func<ConfigurationDebugViewContext, string>? processValue)
  {
  void RecurseChildren(
  StringBuilder stringBuilder,
@@ -29,11 +46,15 @@ void RecurseChildren(
 
  if (valueAndProvider.Provider != null)
  {
+ string? value = processValue != null
+ ? processValue(new ConfigurationDebugViewContext(child.Key, child.Path, valueAndProvider.Value, valueAndProvider.Provider))
+ : valueAndProvider.Value;
+
  stringBuilder
  .Append(indent)
  .Append(child.Key)
  .Append('=')
- .Append(valueAndProvider.Value)
+ .Append(value)
  .Append(" (")
  .Append(valueAndProvider.Provider)
  .AppendLine(")");