Swagger Codegen for OAS3 - swagger

Question

I'm trying to use Swagger Codegen for my OAS3 project.
I have cloned swagger-codegen branch 3.0.0. and when I run the generate command I get the following error:
[main] ERROR io.swagger.parser.SwaggerCompatConverter - failed to read resource listing
com.fasterxml.jackson.core.JsonParseException: Unrecognized token 'openapi': was expecting ('true', 'false' or 'null')
at [Source: (String)"openapi: 3.0.0
Does Codegen supports openapi 3.0.1 yet? If yes what am I missing ?
UPDATE - Yaml file and codegen command
Petstore.yaml file :
openapi: "3.0.0"
info:
version: 1.0.0
title: Swagger Petstore
license:
name: MIT
servers:
- url: http://petstore.swagger.io/v1
paths:
/pets:
get:
summary: List all pets
operationId: listPets
tags:
- pets
parameters:
- name: limit
in: query
description: How many items to return at one time (max 100)
required: false
schema:
type: integer
format: int32
responses:
'200':
description: A paged array of pets
headers:
x-next:
description: A link to the next page of responses
schema:
type: string
content:
application/json:
schema:
$ref: "#/components/schemas/Pets"
default:
description: unexpected error
content:
application/json:
schema:
$ref: "#/components/schemas/Error"
post:
summary: Create a pet
operationId: createPets
tags:
- pets
responses:
'201':
description: Null response
default:
description: unexpected error
content:
application/json:
schema:
$ref: "#/components/schemas/Error"
components:
schemas:
Pet:
type: object
required:
- id
- name
properties:
id:
type: integer
format: int64
name:
type: string
tag:
type: string
Pets:
type: array
items:
$ref: "#/components/schemas/Pet"
Error:
type: object
required:
- code
- message
properties:
code:
type: integer
format: int32
message:
type: string
Codegen command:
SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
java -jar ./swagger-codegen/modules/swagger-codegen-cli/target/swagger-codegen-cli.jar generate -i "./definitions/petstoreV3.yaml" -l javascript -o "$SCRIPT_DIR/.swagger_gen_temp"

Answer 1

The error occurs because you are running V2 codegen (from the master branch) instead of V3 codegen (from the 3.0.0 branch). V2 codegen does not support OpenAPI 3.0.
You can download the JAR of V3 codegen from:
http://central.maven.org/maven2/io/swagger/codegen/v3/swagger-codegen-cli/3.0.11/swagger-codegen-cli-3.0.11.jar
V3 codegen, however, does not currently have a JavaScript client generator.