improvement: Enum values expose New() to ease creating new container types

changelog/@unreleased/pr-542.v2.yml

@@ -0,0 +1,5 @@
+type: improvement
+improvement:
+  description: Enum values expose New() to ease creating new container types
+  links:
+  - https://github.com/palantir/conjure-go/pull/542

conjure/enumwriter.go

@@ -30,6 +30,7 @@ const (
 func writeEnumType(file *jen.Group, enumDef *types.EnumType) {
 	file.Add(enumDef.CommentLineWithDeprecation(enumDef.Deprecated)).Add(astForEnumTypeDecls(enumDef.Name))
 	file.Add(astForEnumValueConstants(enumDef.Name, enumDef.Values))
+	file.Add(astForEnumValueMethodNew(enumDef.Name))
 	file.Add(astForEnumValuesFunction(enumDef.Name, enumDef.Values))
 	file.Add(astForEnumConstructor(enumDef.Name))
 	file.Add(astForEnumIsUnknown(enumDef.Name, enumDef.Values))
@@ -55,6 +56,17 @@ func astForEnumValueConstants(typeName string, values []*types.Field) *jen.State
 	})
 }
 
+func astForEnumValueMethodNew(typeName string) *jen.Statement {
+	return jen.Func().
+		Params(jen.Id(enumReceiverName).Id(typeName + "_Value")).
+		Id("New").
+		Params().
+		Params(jen.Id(typeName)).
+		Block(
+			jen.Return(jen.Id(typeName).Values(jen.Id(enumStructFieldName).Op(":").Id(enumReceiverName))),
+		)
+}
+
 func astForEnumValuesFunction(typeName string, enumValues []*types.Field) *jen.Statement {
 	return jen.Commentf("%s_Values returns all known variants of %s.", typeName, typeName).
 		Line().
@@ -127,7 +139,7 @@ func astForEnumUnmarshalText(typeName string, values []*types.Field) *jen.Statem
 			jen.Id(enumUpperVarName),
 		).BlockFunc(func(cases *jen.Group) {
 			assign := func(val jen.Code) *jen.Statement {
-				return jen.Op("*").Add(jen.Id(enumReceiverName)).Op("=").Id("New_" + typeName).Call(val)
+				return jen.Op("*").Add(jen.Id(enumReceiverName)).Op("=").Add(val).Dot("New").Call()
 			}
 			cases.Default().Block(assign(jen.Id(typeName + "_Value").Call(jen.Id(enumUpperVarName))))
 			for _, valDef := range values {

conjure/serverwriter.go

@@ -527,11 +527,11 @@ func argDefLogSafety(argDef *types.EndpointArgumentDefinition) spec.LogSafety {
 		if ext, ok := marker.(*types.External); ok && ext.Spec.Package == "com.palantir.logsafe" {
 			switch ext.Spec.Name {
 			case "DoNotLog":
-				return spec.New_LogSafety(spec.LogSafety_DO_NOT_LOG)
+				return spec.LogSafety_DO_NOT_LOG.New()
 			case "Safe":
-				return spec.New_LogSafety(spec.LogSafety_SAFE)
+				return spec.LogSafety_SAFE.New()
 			case "Unsafe":
-				return spec.New_LogSafety(spec.LogSafety_UNSAFE)
+				return spec.LogSafety_UNSAFE.New()
 			}
 		}
 	}