[BUG][typescript-angular] Model properties with underscore prefix generates invalid file names/imports using kebab-case file naming

Created by: roddy

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 an API that follows HAL standards. It includes a _links property defined as an inline object schema. When the typescript-angular generator is run, it creates a typescript file named foo-response--links.ts, but references it as foo-response-links in imports from other files.

I am generating this using the NPM client @openapitools/openapi-generator-cli@1.0.8-4.2.2 which bundles the 4.2.2 generator (I think).

Invoking with: generate --generator-name typescript-angular --input-spec foo.yml --config config.json --skip-validate-spec

Config:

{
  "ngVersion": "7.2.0",
  "fileNaming": "kebab-case",
  "modelPropertyNaming": "original",
  "serviceSuffix": "Service",
  "sortParamsByRequiredFlag": true,
  "prependFormOrBodyParameters": true
}

API example (foo.yml):

openapi: 3.0.0
info:
  title: Example API
  description: An Example API
  version: "1.0"
paths:
  /hello:
    get:
      summary: Example endpoint
      operationId: get_hello
      responses:
        200:
          description: Example response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/FooResponse'
components:
  schemas:
    FooResponse:
      type: object
      properties:
        _links:
          required:
            - collection
            - self
          type: object
          properties:
            collection:
              type: string
              format: uri
            self:
              type: string
              format: uri

Note that the FooResponse schema has a property _links defined as an object.

This generates a foo-response.ts and a foo-response--links.ts (note the double hyphen.)

In foo-response.ts, it tries to import the model from foo-response-links.ts (note the single hyphen) like so:

import { FooResponseLinks } from './foo-response-links';

export interface FooResponse { 
  _links?: FooResponseLinks;
}

Note that when using 'camelCase' file naming, this issue is not present and the model files are generated as fooResponse.ts and fooResponseLinks.ts and linked appropriately.

openapi-generator version

Confirmed that this is an issue with @openapitools/openapi-generator-cli versions:

• 1.0.8-4.2.2 (current latest)
• 1.0.1-4.1.3

Command line used for generation

generate --generator-name typescript-angular --input-spec foo.yml --config config.json --skip-validate-spec

Suggest a fix

The double hyphen in the file name is very unusual but technically valid. The issue is that the logic that determines the file name to use, and the logic that determines the module name to import from is out of sync.

So the fix is either:

• A. Generate a file name foo-response-links.ts without the double hyphen, to match the import. or:
• B. Update the import to be from './foo-response--links' to match the file name.

(I personally prefer solution A because it's more natural.)