RicoSuter/NSwag

Generate typescript client: An interface can only extend an identifier/qualified-name with optional type arguments. [2499]

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#1810 opened on Dec 10, 2018

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help wantedtype: bug

Description

npm: nswag@12.0.5 swagger json: https://raw.githubusercontent.com/MicrosoftDocs/vsts-rest-api-specs/master/specification/build/5.1/build.json

when running with this file and the attached settings I get the error An interface can only extend an identifier/qualified-name with optional type arguments. [2499]

image

nswag.json.txt

Is there a way to avoid this error? Thank you very much!

Contributor guide

Tech stack
csharptypescript
Domain
backendtooling
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
TypeScriptOpenAPINSwag
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
The error 'An interface can only extend an identifier/qualified name with optional type arguments' (code 2499) indicates the TypeScript generator produces invalid syntax. To reproduce, run NSwag with the provided Swagger JSON and nswag.json settings. Inspect the TypeScript client generator code (likely 'TypeScriptClientGenerator.cs') to see how interfaces extending other types are emitted. Look for handling of type aliases or complex types that cannot be directly extended. No linked PRs exist, so this is untouched. Maintainers may need to clarify if the Swagger spec is invalid or if NSwag should support this case.