I've used the standard petshop examples from OpenAPI:

And used the following generators with their default options:

openapi-typscript-codegen aurelia inversify angular fetch jquery node
Supports OpenApi v2 specification
Supports OpenApi v3 specification
Supports authentication
Strongly typed models
Strongly typed enums
Models and services exported as individual files
Index file that exports all services and models
Service returns typed result
Service supports sending and receiving binary content
Models and services contain inline documentation
Framework agnostic
Generated size (typescript) 30Kb 30Kb 30Kb 30Kb 30Kb 30Kb 30Kb
Build size (javascript) 30Kb 30Kb 30Kb 30Kb 30Kb 30Kb 30Kb
Generation time 0.132s 0.715s 0.788s 1.386s 1.103s 0.728s 0.752s