[feat] Add function to retrieve API keys for a specific user

CHANGELOG.md

@@ -1,5 +1,9 @@
 # CHANGELOG
 
+## Next Release
+
+- Add `RetrieveApiKeysForUser` to `ApiKey` service
+
 ## v5.7.0 (2023-09-05)
 
 - Fix FedEx SmartPost carrier account creation not going to the correct endpoint

EasyPost.Tests/ServicesTests/ApiKeyServiceTest.cs

@@ -1,4 +1,7 @@
+using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
+using EasyPost.Exceptions.General;
 using EasyPost.Models.API;
 using EasyPost.Tests._Utilities;
 using EasyPost.Tests._Utilities.Attributes;
@@ -39,6 +42,33 @@ public async Task TestAll()
             }
         }
 
+        [Fact]
+        [CrudOperations.Read]
+        public async Task TestRetrieveApiKeys()
+        {
+            UseVCR("retrieve_api_keys");
+
+            User user = await Client.User.RetrieveMe();
+
+            List<ApiKey> apiKeys = await Client.ApiKey.RetrieveApiKeysForUser(user.Id);
+
+            Assert.IsType<List<ApiKey>>(apiKeys);
+        }
+
+        [Fact]
+        [CrudOperations.Read]
+        public async Task TestRetrieveApiKeysChild()
+        {
+            UseVCR("retrieve_api_keys_child");
+
+            const string fakeChildId = "user_123456789";
+
+            // Test suite user has no child users, so this should throw a FilteringError
+            Exception? possibleException = await Record.ExceptionAsync(async () => await Client.ApiKey.RetrieveApiKeysForUser(fakeChildId));
+
+            Assert.IsType<FilteringError>(possibleException);
+        }
+
         #endregion
 
         #endregion

EasyPost/Services/ApiKeyService.cs

@@ -1,6 +1,10 @@
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using EasyPost._base;
+using EasyPost.Exceptions.General;
 using EasyPost.Http;
 using EasyPost.Models.API;
 using EasyPost.Utilities.Internal.Attributes;
@@ -33,6 +37,35 @@ internal ApiKeyService(EasyPostClient client)
         [CrudOperations.Read]
         public async Task<ApiKeyCollection> All(CancellationToken cancellationToken = default) => await RequestAsync<ApiKeyCollection>(Method.Get, "api_keys", cancellationToken);
 
+        /// <summary>
+        ///     Retrieve the <see cref="ApiKey"/>s for a specific <see cref="User"/>.
+        /// </summary>
+        /// <param name="id">The ID of the <see cref="User"/> to retrieve keys for.</param>
+        /// <param name="cancellationToken"><see cref="CancellationToken"/> to use for the HTTP request.</param>
+        /// <returns>A list of <see cref="ApiKey"/>s for the specified <see cref="User"/>.</returns>
+        /// <exception cref="FilteringError">Thrown if the specified <see cref="User"/> does not exist.</exception>
+        public async Task<List<ApiKey>?> RetrieveApiKeysForUser(string id, CancellationToken cancellationToken = default)
+        {
+            ApiKeyCollection apiKeyCollection = await All(cancellationToken);
+
+            if (apiKeyCollection.Id == id)
+            {
+                return apiKeyCollection.Keys;
+            }
+
+            if (apiKeyCollection.Children == null)
+            {
+                throw new FilteringError(string.Format(CultureInfo.InvariantCulture, Constants.ErrorMessages.NoObjectFound, "child"));
+            }
+
+            foreach (ApiKeyCollection child in apiKeyCollection.Children.Where(child => child.Id == id))
+            {
+                return child.Keys;
+            }
+
+            throw new FilteringError(string.Format(CultureInfo.InvariantCulture, Constants.ErrorMessages.NoObjectFound, "child"));
+        }
+
         #endregion
     }
 }