Move config file to jsonc, make config class nullable

Author: benrr101

.gitignore

@@ -370,6 +370,7 @@ MigrationBackup/
 
 # Config Json file
 **/config.json
+**/config.jsonc
 
 # Generated Milestone PR metadata files
 .milestone-prs/

src/Microsoft.Data.SqlClient/tests/tools/Microsoft.Data.SqlClient.TestUtilities/Config.cs

@@ -6,69 +6,63 @@
 using System.IO;
 using Newtonsoft.Json;
 
+#nullable enable
+
 namespace Microsoft.Data.SqlClient.TestUtilities
 {
     public class Config
     {
-        public string TCPConnectionString = null;
-        public string NPConnectionString = null;
-        public string TCPConnectionStringHGSVBS = null;
-        public string TCPConnectionStringNoneVBS = null;
-        public string TCPConnectionStringAASSGX = null;
+        public string? TCPConnectionString = null;
+        public string? NPConnectionString = null;
+        public string? TCPConnectionStringHGSVBS = null;
+        public string? TCPConnectionStringNoneVBS = null;
+        public string? TCPConnectionStringAASSGX = null;
         public bool EnclaveEnabled = false;
         public bool TracingEnabled = false;
-        public string AADAuthorityURL = null;
-        public string AADPasswordConnectionString = null;
-        public string AADServicePrincipalId = null;
-        public string AADServicePrincipalSecret = null;
-        public string AzureKeyVaultURL = null;
-        public string AzureKeyVaultTenantId = null;
+        public string? AADAuthorityURL = null;
+        public string? AADPasswordConnectionString = null;
+        public string? AADServicePrincipalId = null;
+        public string? AADServicePrincipalSecret = null;
+        public string? AzureKeyVaultURL = null;
+        public string? AzureKeyVaultTenantId = null;
         public bool SupportsIntegratedSecurity = false;
-        public string LocalDbAppName = null;
-        public string LocalDbSharedInstanceName = null;
-        public string FileStreamDirectory = null;
+        public string? LocalDbAppName = null;
+        public string? LocalDbSharedInstanceName = null;
+        public string? FileStreamDirectory = null;
         public bool UseManagedSNIOnWindows = false;
-        public string DNSCachingConnString = null;
-        public string DNSCachingServerCR = null;  // this is for the control ring
-        public string DNSCachingServerTR = null;  // this is for the tenant ring
+        public string? DNSCachingConnString = null;
+        public string? DNSCachingServerCR = null;  // this is for the control ring
+        public string? DNSCachingServerTR = null;  // this is for the tenant ring
         public bool IsDNSCachingSupportedCR = false;  // this is for the control ring
         public bool IsDNSCachingSupportedTR = false;  // this is for the tenant ring
-        public string EnclaveAzureDatabaseConnString = null;
+        public string? EnclaveAzureDatabaseConnString = null;
         public bool ManagedIdentitySupported = true;
-        public string UserManagedIdentityClientId = null;
-        public string PowerShellPath = null;
-        public string AliasName = null;
-        public string KerberosDomainPassword = null;
-        public string KerberosDomainUser = null;
+        public string? UserManagedIdentityClientId = null;
+        public string? PowerShellPath = null;
+        public string? AliasName = null;
+        public string? KerberosDomainPassword = null;
+        public string? KerberosDomainUser = null;
         public bool IsManagedInstance = false;
 
-        public static Config Load(string configPath = @"config.json")
+        public static Config Load(string configPath)
         {
-            // Allow an override of the config path via an environment variable.
-            configPath = Environment.GetEnvironmentVariable("TEST_MDS_CONFIG") ?? configPath;
+            Config config = LoadInternal(Environment.GetEnvironmentVariable("TEST_MDS_CONFIG")) ??
+                            LoadInternal(configPath) ??
+                            throw new FileNotFoundException("Could not find test configuration file.");
 
-            Config config;
-            try
-            {
-                using (StreamReader r = new StreamReader(configPath))
-                {
-                    config = JsonConvert.DeserializeObject<Config>(r.ReadToEnd())
-                        ?? throw new InvalidOperationException($"Failed to deserialize config from '{configPath}'.");
-                }
-            }
-            catch
-            {
-                throw;
-            }
+            // Allow environment variables to override individual config values.
+            SetFromEnv("MDS_TCPConnectionString", ref config.TCPConnectionString);
 
-            static void SetFromEnv(string envVar, ref string configValue)
-            {
-                string envValue = Environment.GetEnvironmentVariable(envVar);
-                if (!string.IsNullOrEmpty(envValue))
-                {
-                    configValue = envValue;
-                }
-            }
+            return config;
+        }
+
+        public static Config Load()
+        {
+            // Load config from environment variable first, jsonc file second, json file last.
+            Config config = LoadInternal(Environment.GetEnvironmentVariable("TEST_MDS_CONFIG")) ??
+                            LoadInternal("config.jsonc") ??
+                            LoadInternal("config.json") ??
+                            throw new FileNotFoundException("Could not find test configuration file.");
 
             // Allow environment variables to override individual config values.
             SetFromEnv("MDS_TCPConnectionString", ref config.TCPConnectionString);
@@ -81,5 +75,34 @@ public static void UpdateConfig(Config updatedConfig, string configPath = @"conf
             string config = JsonConvert.SerializeObject(updatedConfig);
             File.WriteAllText(configPath, config);
         }
+
+        private static Config? LoadInternal(string? configPath)
+        {
+            if (configPath is null)
+            {
+                return null;
+            }
+
+            try
+            {
+                using StreamReader sr = new StreamReader(configPath);
+                return JsonConvert.DeserializeObject<Config>(sr.ReadToEnd()) ??
+                       throw new InvalidOperationException($"Failed to deserialize config from '{configPath}'");
+            }
+            catch (FileNotFoundException)
+            {
+                // File did not exist at the path given. We will try a different location.
+                return null;
+            }
+        }
+
+        private static void SetFromEnv(string envVar, ref string? configValue)
+        {
+            string? envValue = Environment.GetEnvironmentVariable(envVar);
+            if (!string.IsNullOrEmpty(envValue))
+            {
+                configValue = envValue;
+            }
+        }
     }
 }

src/Microsoft.Data.SqlClient/tests/tools/Microsoft.Data.SqlClient.TestUtilities/Microsoft.Data.SqlClient.TestUtilities.csproj

@@ -3,10 +3,10 @@
     <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
   <Target Name="CopyConfig" BeforeTargets="Compile">
-    <Copy SourceFiles="config.default.json" DestinationFiles="config.json" Condition="!Exists('config.json')" />
+    <Copy SourceFiles="config.default.jsonc" DestinationFiles="config.jsonc" Condition="!Exists('config.jsonc')" />
   </Target>
   <ItemGroup>
-    <None Update="config.json">
+    <None Update="config.jsonc">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
     <PackageReference Include="Newtonsoft.Json" />