Dump the environment variable prefix in ToString (#56685)

* Dump the environment variable prefix in ToString
- This allows tools that dump the providers (like GetDebugView) to see a little more data about the configured providers when debugging.

diff --git a/src/libraries/Microsoft.Extensions.Configuration.EnvironmentVariables/src/EnvironmentVariablesConfigurationProvider.cs b/src/libraries/Microsoft.Extensions.Configuration.EnvironmentVariables/src/EnvironmentVariablesConfigurationProvider.cs
index 294956a..5ea2911 100644 (file)
--- a/src/libraries/Microsoft.Extensions.Configuration.EnvironmentVariables/src/EnvironmentVariablesConfigurationProvider.cs
+++ b/src/libraries/Microsoft.Extensions.Configuration.EnvironmentVariables/src/EnvironmentVariablesConfigurationProvider.cs
@@ -38,6 +38,13 @@ namespace Microsoft.Extensions.Configuration.EnvironmentVariables
         public override void Load() =>
             Load(Environment.GetEnvironmentVariables());
 
+        /// <summary>
+        /// Generates a string representing this provider name and relevant details.
+        /// </summary>
+        /// <returns> The configuration name. </returns>
+        public override string ToString()
+            => $"{GetType().Name} Prefix: '{_prefix}'";
+
         internal void Load(IDictionary envVariables)
         {
             var data = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);