chore: use constant for extension mechanism

Signed-off-by: Vincent Biret <vibiret@microsoft.com>

Author: baywet

src/Microsoft.OpenApi/Reader/V2/OpenApiContactDeserializer.cs

@@ -32,7 +32,7 @@ internal static partial class OpenApiV2Deserializer
 
         private static readonly PatternFieldMap<OpenApiContact> _contactPatternFields = new()
         {
-            {s => s.StartsWith("x-", StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
+            {s => s.StartsWith(OpenApiConstants.ExtensionFieldNamePrefix, StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
         };
 
         public static OpenApiContact LoadContact(ParseNode node, OpenApiDocument hostDocument)

src/Microsoft.OpenApi/Reader/V2/OpenApiDocumentDeserializer.cs

@@ -111,7 +111,7 @@ internal static partial class OpenApiV2Deserializer
         private static readonly PatternFieldMap<OpenApiDocument> _openApiPatternFields = new()
         {
             // We have no semantics to verify X- nodes, therefore treat them as just values.
-            {s => s.StartsWith("x-", StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
+            {s => s.StartsWith(OpenApiConstants.ExtensionFieldNamePrefix, StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
         };
 
         private static void MakeServers(IList<OpenApiServer> servers, ParsingContext context, RootNode rootNode)

src/Microsoft.OpenApi/Reader/V2/OpenApiExternalDocsDeserializer.cs

@@ -30,7 +30,7 @@ internal static partial class OpenApiV2Deserializer
         private static readonly PatternFieldMap<OpenApiExternalDocs> _externalDocsPatternFields =
                 new()
                 {
-                    {s => s.StartsWith("x-", StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
+                    {s => s.StartsWith(OpenApiConstants.ExtensionFieldNamePrefix, StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
                     };
 
         public static OpenApiExternalDocs LoadExternalDocs(ParseNode node, OpenApiDocument hostDocument)

src/Microsoft.OpenApi/Reader/V2/OpenApiHeaderDeserializer.cs

@@ -95,7 +95,7 @@ internal static partial class OpenApiV2Deserializer
 
         private static readonly PatternFieldMap<OpenApiHeader> _headerPatternFields = new()
         {
-            {s => s.StartsWith("x-"), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
+            {s => s.StartsWith(OpenApiConstants.ExtensionFieldNamePrefix), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
         };
 
         private static OpenApiSchema GetOrCreateSchema(OpenApiHeader p)

src/Microsoft.OpenApi/Reader/V2/OpenApiInfoDeserializer.cs

@@ -44,7 +44,7 @@ internal static partial class OpenApiV2Deserializer
 
         private static readonly PatternFieldMap<OpenApiInfo> _infoPatternFields = new()
         {
-            {s => s.StartsWith("x-", StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
+            {s => s.StartsWith(OpenApiConstants.ExtensionFieldNamePrefix, StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
         };
 
         public static OpenApiInfo LoadInfo(ParseNode node, OpenApiDocument hostDocument)

src/Microsoft.OpenApi/Reader/V2/OpenApiLicenseDeserializer.cs

@@ -28,7 +28,7 @@ internal static partial class OpenApiV2Deserializer
 
         private static readonly PatternFieldMap<OpenApiLicense> _licensePatternFields = new()
         {
-            {s => s.StartsWith("x-", StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
+            {s => s.StartsWith(OpenApiConstants.ExtensionFieldNamePrefix, StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
         };
 
         public static OpenApiLicense LoadLicense(ParseNode node, OpenApiDocument hostDocument)

src/Microsoft.OpenApi/Reader/V2/OpenApiOperationDeserializer.cs

@@ -81,16 +81,16 @@ internal static partial class OpenApiV2Deserializer
         private static readonly PatternFieldMap<OpenApiOperation> _operationPatternFields =
             new()
             {
-                {s => s.StartsWith("x-", StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
+                {s => s.StartsWith(OpenApiConstants.ExtensionFieldNamePrefix, StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
             };
 
         private static readonly FixedFieldMap<OpenApiResponses> _responsesFixedFields = new();
 
         private static readonly PatternFieldMap<OpenApiResponses> _responsesPatternFields =
             new()
             {
-                {s => !s.StartsWith("x-", StringComparison.OrdinalIgnoreCase), (o, p, n, t) => o.Add(p, LoadResponse(n, t))},
-                {s => s.StartsWith("x-", StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
+                {s => !s.StartsWith(OpenApiConstants.ExtensionFieldNamePrefix, StringComparison.OrdinalIgnoreCase), (o, p, n, t) => o.Add(p, LoadResponse(n, t))},
+                {s => s.StartsWith(OpenApiConstants.ExtensionFieldNamePrefix, StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
             };
 
         internal static OpenApiOperation LoadOperation(ParseNode node, OpenApiDocument hostDocument)

src/Microsoft.OpenApi/Reader/V2/OpenApiParameterDeserializer.cs

@@ -106,7 +106,7 @@ internal static partial class OpenApiV2Deserializer
         private static readonly PatternFieldMap<OpenApiParameter> _parameterPatternFields =
             new()
             {
-                {s => s.StartsWith("x-", StringComparison.OrdinalIgnoreCase) && !s.Equals(OpenApiConstants.ExamplesExtension, StringComparison.OrdinalIgnoreCase),
+                {s => s.StartsWith(OpenApiConstants.ExtensionFieldNamePrefix, StringComparison.OrdinalIgnoreCase) && !s.Equals(OpenApiConstants.ExamplesExtension, StringComparison.OrdinalIgnoreCase),
                     (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))} 
             };
 

src/Microsoft.OpenApi/Reader/V2/OpenApiPathItemDeserializer.cs

@@ -34,7 +34,7 @@ internal static partial class OpenApiV2Deserializer
         private static readonly PatternFieldMap<OpenApiPathItem> _pathItemPatternFields =
             new()
             {
-                {s => s.StartsWith("x-", StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))},
+                {s => s.StartsWith(OpenApiConstants.ExtensionFieldNamePrefix, StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))},
             };
 
         public static OpenApiPathItem LoadPathItem(ParseNode node, OpenApiDocument hostDocument)

src/Microsoft.OpenApi/Reader/V2/OpenApiPathsDeserializer.cs

@@ -19,7 +19,7 @@ internal static partial class OpenApiV2Deserializer
         private static readonly PatternFieldMap<OpenApiPaths> _pathsPatternFields = new()
         {
             {s => s.StartsWith("/", StringComparison.OrdinalIgnoreCase), (o, k, n, t) => o.Add(k, LoadPathItem(n, t))},
-            {s => s.StartsWith("x-", StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
+            {s => s.StartsWith(OpenApiConstants.ExtensionFieldNamePrefix, StringComparison.OrdinalIgnoreCase), (o, p, n, _) => o.AddExtension(p, LoadExtension(p, n))}
         };
 
         public static OpenApiPaths LoadPaths(ParseNode node, OpenApiDocument hostDocument)