[BUG] Not resolve relative path to split files in generate command

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What’s the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What’s the actual output vs expected output?
• [Optional] Bounty to sponsor the fix (example)

Description

I have a trouble in file path on $ref property.

The following my open-api schema files split. index.yml is entry point.

api-schema/
├── api
│   └── v1
│       ├── posts.yml
├── index.yml
└── schemas
    └── post.yml

index.yml

openapi: "3.0.0"
info:
  version: 1.0.0
  title: Swagger Petstore
  license:
    name: MIT
servers:
  - url: http://petstore.swagger.io/v1
paths:
  /pets:
    $ref: api/v1/posts.yml#/~1posts

api/v1/posts.yml

/posts:
  get:
    responses:
      '200':
        content:
          application/json:
            schema:
              $ref: './../../schemas/post.yml' # Here is problem!

I use two libraries below.

• https://github.com/OpenAPITools/openapi-generator
• https://github.com/Redocly/redoc

How to resolve path on $ref by them are not same.

api/v1/posts.yml

# Work on redoc. Redoc resolves current path as 'api-schema/api/v1/'.
#
# However not work on openapi-generator. It resolves current path as 'api-schema/'. This is where on index.yml.
# `openapi-generator validate -i api-schema/index.yml`
# Validate of openapi-generator was success.
$ref: './../../schemas/post.yml'

# Work on openapi-generator, but not work on redoc.
$ref: 'schemas/post.yml'

I don’t know which generator or redoc the bug for.

openapi-generator version

4.2.0

OpenAPI declaration file content or url

In my case, files are split.

Command line used for generation

When $ref: './../../schemas/post.yml', openapi-generator fails to generate and output the following.

[main] WARN  io.swagger.v3.parser.OpenAPIV3Parser - Exception while reading:
java.lang.RuntimeException: Unable to load RELATIVE ref: ./../../schemas/post.yml path: /Users/mitsuru/project/example-openapi
	at io.swagger.v3.parser.util.RefUtils.readExternalRef(RefUtils.java:239)
	at io.swagger.v3.parser.ResolverCache.loadRef(ResolverCache.java:119)
	at io.swagger.v3.parser.processors.ExternalRefProcessor.processRefToExternalSchema(ExternalRefProcessor.java:56)
	at io.swagger.v3.parser.processors.SchemaProcessor.processReferenceSchema(SchemaProcessor.java:202)
	at io.swagger.v3.parser.processors.SchemaProcessor.processSchema(SchemaProcessor.java:37)
	at io.swagger.v3.parser.processors.ResponseProcessor.processResponse(ResponseProcessor.java:52)
	at io.swagger.v3.parser.processors.OperationProcessor.processOperation(OperationProcessor.java:67)
	at io.swagger.v3.parser.processors.PathsProcessor.processPaths(PathsProcessor.java:83)
	at io.swagger.v3.parser.OpenAPIResolver.resolve(OpenAPIResolver.java:49)
	at io.swagger.v3.parser.OpenAPIV3Parser.readLocation(OpenAPIV3Parser.java:66)
	at io.swagger.parser.OpenAPIParser.readLocation(OpenAPIParser.java:16)
	at org.openapitools.codegen.config.CodegenConfigurator.toContext(CodegenConfigurator.java:451)
	at org.openapitools.codegen.config.CodegenConfigurator.toClientOptInput(CodegenConfigurator.java:497)
	at org.openapitools.codegen.cmd.Generate.run(Generate.java:415)
	at org.openapitools.codegen.OpenAPIGenerator.main(OpenAPIGenerator.java:61)
Caused by: java.lang.RuntimeException: Could not find ./../../schemas/post.yml on the classpath
	at io.swagger.v3.parser.util.ClasspathHelper.loadFileFromClasspath(ClasspathHelper.java:31)
	at io.swagger.v3.parser.util.RefUtils.readExternalRef(RefUtils.java:233)
	... 14 common frames omitted
[main] WARN  o.o.codegen.utils.ModelUtils - Failed to get the schema name: ./../../schemas/post.yml
[main] WARN  o.o.codegen.utils.ModelUtils - Failed to get the schema name: ./../../schemas/post.yml

Steps to reproduce

see description.

Related issues/PRs

Nothing.

Suggest a fix

I know whether this is bug.

[mitsuru793]

@nugrahawahyu

OK! I am not angry. I have thought to help you☺️ I am Japanese. I’m not good at speaking English. I am poor in expression of English🙏

$ref cannot be used directly under 200: (swagger-cli can handles it though)

Yes! I think it’s correct. I don’t know about openapi correcty😆

[nugrahawahyu]

@mitsuru793 I’m still experiencing the issue (from master, using swagger-parser 2.0.20), care to elaborate how did you solve it?

My setup:

dir tree:

services/test/.
├── openapi.yaml
└── resources
    └── merchants
        ├── components
        │   ├── responses
        │   │   └── Merchants.yaml
        │   └── schemas
        │       ├── Merchant.yaml
        │       └── Merchants.yaml
        └── paths

openapi.yaml:

openapi: 3.0.0
info:
  version: 1.0.0
  title: Marketplace
servers:
  - url: 'http://localhost:3039'
paths:
  /marketplace/merchants:
    $ref: 'resources/merchants/paths/actions.yaml'

resources/merchants/components/paths/actions.yaml:

get:
  summary: 'List'
  operationId: listMerchant
  tags:
    - merchant
  responses:
    200:
      $ref: '../components/responses/Merchants.yaml'

resources/merchants/components/responses/Merchant.yaml:

description: 'Merchant List'
content:
  application/json:
    schema:
      type: object
      properties:
        data:
          type: object
          properties:
            items:
              $ref: ../schemas/Merchants.yaml

resources/merchants/components/schemas/Merchant.yaml:

type: object
required:
  - address_id
  - name
properties:
  address_id:
    type: string
    format: uuid
  name:
    type: string
  description:
    type: string

resources/merchants/components/schemas/Merchants.yaml:

type: array
items:
  $ref: "Merchant.yaml"

Command line used for generation:

./mvnw clean install

java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate \ 
  -i ~/test_project/api_schema/services/test/openapi.yaml \
  -g javascript \
  -o ~/test_project/client/test/javascript

Output:

[main] WARN  io.swagger.v3.parser.OpenAPIV3Parser - Exception while reading:
java.lang.RuntimeException: Unable to load RELATIVE ref: ../components/responses/Merchants.yaml path: /Users/user/test_project/api_schema/services/test
	at io.swagger.v3.parser.util.RefUtils.readExternalRef(RefUtils.java:239)
	at io.swagger.v3.parser.ResolverCache.loadRef(ResolverCache.java:119)
	at io.swagger.v3.parser.processors.ExternalRefProcessor.processRefToExternalResponse(ExternalRefProcessor.java:344)
	at io.swagger.v3.parser.processors.ResponseProcessor.processReferenceResponse(ResponseProcessor.java:84)
	at io.swagger.v3.parser.processors.ResponseProcessor.processResponse(ResponseProcessor.java:41)
	at io.swagger.v3.parser.processors.OperationProcessor.processOperation(OperationProcessor.java:56)
	at io.swagger.v3.parser.processors.PathsProcessor.processPaths(PathsProcessor.java:84)
	at io.swagger.v3.parser.OpenAPIResolver.resolve(OpenAPIResolver.java:49)
	at io.swagger.v3.parser.OpenAPIV3Parser.readLocation(OpenAPIV3Parser.java:67)
	at io.swagger.parser.OpenAPIParser.readLocation(OpenAPIParser.java:16)
	at org.openapitools.codegen.config.CodegenConfigurator.toContext(CodegenConfigurator.java:510)
	at org.openapitools.codegen.config.CodegenConfigurator.toClientOptInput(CodegenConfigurator.java:560)
	at org.openapitools.codegen.cmd.Generate.execute(Generate.java:424)
	at org.openapitools.codegen.cmd.OpenApiGeneratorCommand.run(OpenApiGeneratorCommand.java:32)
	at org.openapitools.codegen.OpenAPIGenerator.main(OpenAPIGenerator.java:66)
Caused by: java.lang.RuntimeException: Could not find ../components/responses/Merchants.yaml on the classpath
	at io.swagger.v3.parser.util.ClasspathHelper.loadFileFromClasspath(ClasspathHelper.java:31)
	at io.swagger.v3.parser.util.RefUtils.readExternalRef(RefUtils.java:233)
	... 14 common frames omitted
[main] WARN  o.o.codegen.utils.ModelUtils - Failed to get the schema name: ../components/responses/Merchants.yaml
Exception in thread "main" org.openapitools.codegen.SpecValidationException: There were issues with the specification. The option can be disabled via validateSpec (Maven/Gradle) or --skip-validate-spec (CLI).
 | Error count: 1, Warning count: 0
Errors:
	-Unable to load RELATIVE ref: ../components/responses/Merchants.yaml path: /Users/user/test_project/api_schema/services/test

	at org.openapitools.codegen.config.CodegenConfigurator.toContext(CodegenConfigurator.java:533)
	at org.openapitools.codegen.config.CodegenConfigurator.toClientOptInput(CodegenConfigurator.java:560)
	at org.openapitools.codegen.cmd.Generate.execute(Generate.java:424)
	at org.openapitools.codegen.cmd.OpenApiGeneratorCommand.run(OpenApiGeneratorCommand.java:32)
	at org.openapitools.codegen.OpenAPIGenerator.main(OpenAPIGenerator.java:66)