Cast string to OpenApiSpecVersion enum value

Author: MaggieKimani1

src/Microsoft.OpenApi.Hidi/OpenApiService.cs

@@ -22,6 +22,7 @@
 using Microsoft.OpenApi.Services;
 using Microsoft.OpenApi.Validations;
 using Microsoft.OpenApi.Writers;
+using static Microsoft.OpenApi.Hidi.OpenApiSpecVersionExtension;
 
 namespace Microsoft.OpenApi.Hidi
 {
@@ -31,7 +32,7 @@ public static async Task ProcessOpenApiDocument(
             string openapi,
             string csdl,
             FileInfo output,
-            OpenApiSpecVersion? version,
+            string? version,
             OpenApiFormat? format,
             LogLevel loglevel,
             bool inline,
@@ -83,13 +84,14 @@ string filterbycollection
             Stream stream;
             OpenApiDocument document;
             OpenApiFormat openApiFormat;
+            OpenApiSpecVersion? openApiVersion = null;
             var stopwatch = new Stopwatch();
 
             if (!string.IsNullOrEmpty(csdl))
             {
                 // Default to yaml and OpenApiVersion 3 during csdl to OpenApi conversion
                 openApiFormat = format ?? GetOpenApiFormat(csdl, logger);
-                version ??= OpenApiSpecVersion.OpenApi3_0;
+                openApiVersion = version.TryParseOpenApiSpecVersion();
 
                 stream = await GetStream(csdl, logger);
                 document = await ConvertCsdlToOpenApi(stream);
@@ -128,7 +130,7 @@ string filterbycollection
                 }
 
                 openApiFormat = format ?? GetOpenApiFormat(openapi, logger);
-                version ??= result.OpenApiDiagnostic.SpecificationVersion;
+                openApiVersion ??= result.OpenApiDiagnostic.SpecificationVersion;
             }
 
             Func<string, OperationType?, OpenApiOperation, bool> predicate;
@@ -185,14 +187,14 @@ string filterbycollection
             logger.LogTrace("Serializing to OpenApi document using the provided spec version and writer");
 
             stopwatch.Start();
-            document.Serialize(writer, (OpenApiSpecVersion)version);
+            document.Serialize(writer, (OpenApiSpecVersion)openApiVersion);
             stopwatch.Stop();
 
             logger.LogTrace($"Finished serializing in {stopwatch.ElapsedMilliseconds}ms");
 
             textWriter.Flush();
         }
-
+        
         /// <summary>
         /// Converts CSDL to OpenAPI
         /// </summary>

src/Microsoft.OpenApi.Hidi/OpenApiSpecVersionExtension.cs

@@ -0,0 +1,31 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license.
+
+using System;
+using System.Linq;
+
+namespace Microsoft.OpenApi.Hidi
+{
+    public static class OpenApiSpecVersionExtension
+    {
+        public static OpenApiSpecVersion TryParseOpenApiSpecVersion(this string value)
+        {
+            if (string.IsNullOrEmpty(value))
+            {
+                throw new InvalidOperationException("Please provide a version");
+            }
+            var res = value.Split('.', StringSplitOptions.RemoveEmptyEntries).FirstOrDefault();
+            
+            if (int.TryParse(res, out int result))
+            {
+
+                if (result >= 2 || result <= 3)
+                {
+                    return (OpenApiSpecVersion)result;
+                }
+            }  
+
+            return OpenApiSpecVersion.OpenApi3_0; // default
+        }
+    }
+}