How to parse URL with placeholder?

[selman92]

I have a swagger document that starts like this:

{ "swagger": "2.0", "info": { "title": "Foo", "version": "1.3.0" }, "x-basePath": "{ipaddress}/bar/api/v0", "schemes": [ "https" ], }

As you can see the host part of the uri is a placeholder, does OpenAPI support this? I got an error when I tried to parse with OpenApiStreamReader

System.UriFormatException
  HResult=0x80131537
  Message=Invalid URI: The hostname could not be parsed.
  Source=System

[darrelmiller]

@selman92 Have you tried with the latest version of the library? I tried your example in the workbench tool and got the following:

openapi: 3.0.1
info:
  title: Foo
  version: 1.3.0
servers:
  - url: https://example.org//
paths: { }
x-basePath: '{ipaddress}/bar/api/v0'

There is an issue with the URL that gets generated in #/servers[0]/url however, I don't see how that would generate the error you are seeing.

[selman92]

The version I use is v1.0.0-beta015, haven't tried with v1.0.0-beta17 yet. There is no url definition like this in the document, could that be the problem?

servers:
  - url: https://example.org//

In our project we are using AutoRest library and it parses the document without any problems. But since AutoRest doesn't support swagger 3.0 we want to switch OpenAPI.NET.

[selman92]

This is the full stack trace of the error:

   at System.Uri.CreateThis(String uri, Boolean dontEscape, UriKind uriKind)
   at System.Uri..ctor(String uriString, UriKind uriKind)
   at Microsoft.OpenApi.Readers.V2.OpenApiV2Deserializer.<>c.<.cctor>b__68_150(OpenApiSecurityScheme o, ParseNode n)
   at Microsoft.OpenApi.Readers.ParseNodes.PropertyNode.ParseField[T](T parentInstance, IDictionary`2 fixedFields, IDictionary`2 patternFields)
   at Microsoft.OpenApi.Readers.V2.OpenApiV2Deserializer.LoadSecurityScheme(ParseNode node)
   at Microsoft.OpenApi.Readers.ParseNodes.MapNode.<>c__DisplayClass7_0`1.<CreateMapWithReference>b__0(KeyValuePair`2 n)
   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()
   at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer)
   at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector)
   at Microsoft.OpenApi.Readers.ParseNodes.MapNode.CreateMapWithReference[T](ReferenceType referenceType, Func`2 map)
   at Microsoft.OpenApi.Readers.V2.OpenApiV2Deserializer.<>c.<.cctor>b__68_16(OpenApiDocument o, ParseNode n)
   at Microsoft.OpenApi.Readers.ParseNodes.PropertyNode.ParseField[T](T parentInstance, IDictionary`2 fixedFields, IDictionary`2 patternFields)
   at Microsoft.OpenApi.Readers.V2.OpenApiV2Deserializer.ParseMap[T](MapNode mapNode, T domainObject, FixedFieldMap`1 fixedFieldMap, PatternFieldMap`1 patternFieldMap, List`1 requiredFields)
   at Microsoft.OpenApi.Readers.V2.OpenApiV2Deserializer.LoadOpenApi(RootNode rootNode)
   at Microsoft.OpenApi.Readers.V2.OpenApiV2VersionService.LoadDocument(RootNode rootNode)
   at Microsoft.OpenApi.Readers.ParsingContext.Parse(YamlDocument yamlDocument, OpenApiDiagnostic diagnostic)
   at Microsoft.OpenApi.Readers.OpenApiStreamReader.Read(Stream input, OpenApiDiagnostic& diagnostic)
   at ConsoleApp15.Program.Main(String[] args) in C:\foobar\Program.cs:line 17

[immitev]

I encountered a similar issue in the context of securityDefinitions element.

The OpenAPI JSON file uses a placeholder:

"authorizationUrl": "https://{yourwhitelabel}.acme.com/oauth/authorise",
"tokenUrl": "https://{yourwhitelabel}.acme.com/oauth/token",

And it seems like a good idea for the parser to be more forgiving and not throw error in this occasion. 🤔