Dealing with optional values in responses.

src/Templates/FieldsToSDKSubTemplate.cshtml

@@ -62,8 +62,9 @@
         var itrVarName = "tmpParamItemOf" + baseVarName;
         var valVarName = "tmpParamValueOf" + baseVarName;
 
-@:@(Indentation)@(tempName) := make(@(TypeToString(typeOverride ?? Model.Type, "sdk"))@(isArray ? ", 0" : string.Empty))
-@:@(IncludeLoadFields(Model.Data.BackingField, $"for {keyVarName}, {itrVarName} := range {{0}}")) {
+@:@(IncludeLoadFields(Model.Data.BackingField,
+    $"{tempName} := make({TypeToString(typeOverride ?? Model.Type, "sdk")}{(isArray ? ", 0" : string.Empty)})\r\n".EscapeFormatString() +
+    $"for {keyVarName}, {itrVarName} := range {{0}}")) {
 
         Indentation.Indent();
         Model.FieldDefs.Push(new Dictionary<string, string>());

src/Templates/LoadFieldsDefSubTemplate.cshtml

@@ -18,7 +18,7 @@
     var existDefinition = Model.FieldDefs.FirstOrDefault(def => def.ContainsKey(Model.Field.PropertyPath));
     if (existDefinition != null)
     {
-@:@(Indentation)@(string.Format(Model.TargetFormat, existDefinition[Model.Field.PropertyPath]))
+@:@(Indentation.ApplyToMultiline(string.Format(Model.TargetFormat, existDefinition[Model.Field.PropertyPath])))
         return;
     }
 
@@ -42,21 +42,21 @@
         var getStatement = $"d.Get(\"{Model.Field.Name}\")";
         if (Model.Field.MightBeEmpty)
         {
-@:@(Indentation)if v, paramExists := d.GetOk("@(Model.Field.Name)"); paramExists {
+@:@(Indentation)if paramValue, paramExists := d.GetOk("@(Model.Field.Name)"); paramExists {
             Indentation.Indent();
-            getStatement = "v";
+            getStatement = "paramValue";
         }
-@:@(Indentation)@(string.Format(actualTargetFormat, $"{getStatement}.({TypeToString(Model.Field.GoType, "tf")})"))
+@:@(Indentation.ApplyToMultiline(string.Format(actualTargetFormat, $"{getStatement}.({TypeToString(Model.Field.GoType, "tf")})")))
     }
     else
     {
         var getStatement = $"{definition[Model.Field.Parent.PropertyPath]}[\"{Model.Field.Name}\"]";
         if (Model.Field.MightBeEmpty)
         {
-@:@(Indentation)if v, paramExists := @(getStatement); paramExists {
+@:@(Indentation)if paramValue, paramExists := @(getStatement); paramExists {
             Indentation.Indent();
-            getStatement = "v";
+            getStatement = "paramValue";
         }
-@:@(Indentation)@(string.Format(actualTargetFormat, $"{getStatement}.({TypeToString(Model.Field.GoType, "tf")})"))
+@:@(Indentation.ApplyToMultiline(string.Format(actualTargetFormat, $"{getStatement}.({TypeToString(Model.Field.GoType, "tf")})")))
     }
 }

src/Templates/SDKToFieldsSubTemplate.cshtml

@@ -27,6 +27,14 @@
     var noFieldAccess = isIntermediate && Model.Type.Chain.Count() > 0;
     var noIndirection = (Model.Type.IsSimple && Model.Type.Terminal == GoSDKTerminalTypes.Enum);
     var value = (noIndirection ? string.Empty : "*") + Model.Scope + (noFieldAccess ? $"(*{TypeToString(Model.Type, "sdk")})" : Model.Data.Name);
+    var mightBeEmpty = !Model.Data.OriginalVariable.IsRequired && !noIndirection && !isIntermediate;
+    var isArray = Model.Type.Chain.Any() && Model.Type.Chain.First() == GoSDKNonTerminalTypes.Array;
+    if (mightBeEmpty)
+    {
+@:@(Indentation)if @(value.Substring(1)) != nil @(isArray ? $"&& len({value}) > 0 " : string.Empty){
+        Indentation.Indent();
+    }
+
     if (!Model.Type.Chain.Any())
     {
         if (Model.Data.GoType.Terminal != GoSDKTerminalTypes.Complex)
@@ -45,7 +53,6 @@
     {
         var valueType = Model.Type.StripNonTerminal();
         var baseVarName = GetNonTerminalBaseVariableName();
-        var isArray = Model.Type.Chain.First() == GoSDKNonTerminalTypes.Array;
 
         var tempName = "tmpRespOf" + baseVarName;
         var keyVarName = (isArray ? "_" : "tmpRespKeyOf" + baseVarName);
@@ -96,4 +103,10 @@
         }
 
     }
+
+    if (mightBeEmpty)
+    {
+        Indentation.Outdent();
+@:@(Indentation)}
+    }
 }

src/Templates/TfProviderTemplateBase.cs

@@ -1,4 +1,5 @@
 using AutoRest.Core;
+using AutoRest.Core.Utilities;
 using System;
 using System.Linq;
 using static AutoRest.Core.Utilities.DependencyInjection;
@@ -16,6 +17,8 @@ namespace AutoRest.Terraform
         public void Outdent() => IndentationLevel = Math.Max(IndentationLevel - 1, 0);
 
         public override string ToString() => string.Join(string.Empty, Enumerable.Repeat(IndentationWord, IndentationLevel));
+
+        public string ApplyToMultiline(string lines) => IndentedStringBuilder.IndentMultilineString(ToString() + lines, ToString());
     }
 
     public class TfProviderTemplateBase<T>

src/utilities/ExtendedRegex.cs

@@ -21,6 +21,8 @@ namespace AutoRest.Terraform
         public static readonly string AnyPathExtension = AnyPathExtName.ToExtensionString();
 
 
+        public static string EscapeFormatString(this string format) => format.Replace("{", "{{").Replace("}", "}}");
+
         private static string ToAttributeString(this object obj) => AttributeStart + obj + AttributeEnd;
         private static string ToExtensionString(this string extension) => ExtensionStart + extension + ExtensionEnd;
         private static string WrapByFormatBraces(this object content) => $"{{{content}}}";