Retrieve Format property

Author: irvinesunday

src/Microsoft.OpenApi/Models/OpenApiSchema.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license. 
 
 using System.Collections.Generic;
@@ -630,6 +630,10 @@ internal void WriteAsSchemaProperties(
             }
 
             // format
+            Format ??= AllOf?.FirstOrDefault(x => x.Format != null)?.Format ??
+                    AnyOf?.FirstOrDefault(x => x.Format != null)?.Format ??
+                    OneOf?.FirstOrDefault(x => x.Format != null)?.Format;
+
             writer.WriteProperty(OpenApiConstants.Format, Format);
 
             // title
@@ -695,7 +699,7 @@ internal void WriteAsSchemaProperties(
             // allOf
             writer.WriteOptionalCollection(OpenApiConstants.AllOf, AllOf, (w, s) => s.SerializeAsV2(w));
 
-            // If there isn't already an AllOf, and the schema contains a oneOf or anyOf write an allOf with the first
+            // If there isn't already an allOf, and the schema contains a oneOf or anyOf write an allOf with the first
             // schema in the list as an attempt to guess at a graceful downgrade situation.
             if (AllOf == null || AllOf.Count == 0)
             {
@@ -707,12 +711,6 @@ internal void WriteAsSchemaProperties(
                     // oneOf (Not Supported in V2) - Write the first schema only as an allOf.
                     writer.WriteOptionalCollection(OpenApiConstants.AllOf, OneOf?.Take(1), (w, s) => s.SerializeAsV2(w));
                 }
-                if (OneOf?.Count > 0)
-                {
-                    // Take the format and set it at the root
-                    var oneOfFormat = OneOf.Select<OpenApiSchema, string>(x => x.Format.ToString()).FirstOrDefault();
-                    this.Format = oneOfFormat;
-                }
             }
 
             // properties

test/Microsoft.OpenApi.Tests/Models/OpenApiSchemaTests.cs

@@ -448,7 +448,7 @@ public void SerializeSchemaPrimitiveTypeShouldRemoveFormatInRootIfPresentInChild
             schema.SerializeAsV2(openApiJsonWriter);
             openApiJsonWriter.Flush();
 
-            var v2Schema = outputStringWriter.GetStringBuilder().ToString();//.Replace(Environment.NewLine, "").Replace(" ", "").Replace("\n","");
+            var v2Schema = outputStringWriter.GetStringBuilder().ToString().MakeLineBreaksEnvironmentNeutral();//.Replace(Environment.NewLine, "").Replace(" ", "").Replace("\n","");
 
             // Serialize as V3
             //schema.SerializeAsV3(openApiJsonWriter);
@@ -457,13 +457,14 @@ public void SerializeSchemaPrimitiveTypeShouldRemoveFormatInRootIfPresentInChild
             //var v3Schema = outputStringWriter.GetStringBuilder().ToString();//.Replace(Environment.NewLine, "").Replace(" ", "").Replace("\n", "");
 
             var expectedV2Schema = @"{
-""allOf"": [
-{
-    ""format"": ""decimal"",
-    ""type"": ""number""
-}],
-""format"": ""decimal""
-}".Replace(Environment.NewLine, "").Replace(" ", "").Replace("\n","");
+  ""format"": ""decimal"",
+  ""allOf"": [
+    {
+      ""format"": ""decimal"",
+      ""type"": ""number""
+    }
+  ]
+}".MakeLineBreaksEnvironmentNeutral();
 
 
             var expectedV3Schema = @"{