[bug][typescript] Fix node client generator import file paths

Created by: mahirk

Bug and Recap

Issue: Resolves https://github.com/OpenAPITools/openapi-generator/issues/7385

For mapping such as:

  "importMappings": {
    "Pet": "../dataModel/petModel"
  }

Actual

import { AModelPetModel } from '../../dataModel/petModel';

Expected

import { Pet } from '../dataModel/petModel';

For a mapping such as:

  "importMappings": {
    "Pet": "@company/prefix-zoo-store"
  }

Actual

import { NyPrefixZooStore } from '../@company/prefix-zoo-store';

Expected

import { Pet } from '@company/prefix-zoo-store';

Method

Below is the map in operations.get("imports") based on the import location:

Model is created by generator

[{import=model/pet, classname=Pet}]

BYOModel

[{import=@company/prefix-zoo-store, classname=Pet}]

Therefore the logic was updated to a simpler version, assuming the mapping is created by prior areas.

for (Map<String, Object> im : imports) {
     im.put("filename", im.get("import").toString());
}

This resulted in the following import for:

Created Model

import { Pet } from '../model/pet';

BYOModel

import { Pet } from '../@company/prefix-zoo-store';

Per the above, this fixed the issue of the improper render which led to the bad classname i.e. what led to the following NyPrefixZooStore

The next issue was the extra ../ which is embedded as part of the template. See: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/resources/typescript-node/api-single.mustache#L8

For this purpose, the extra directory listing was remove from the template and added into the Codegen itself, where the ../ is appended by default ONLY when the model is derived from an auto generated file.

After this change here are the mappings in operations.get("imports")

Model is created by generator

[{import=../model/pet, classname=Pet}]

BYOModel

[{import=@company/prefix-zoo-store, classname=Pet}]

This resulted in the following import for:

Created Model

import { Pet } from '../model/pet';

BYOModel

import { Pet } from '@company/prefix-zoo-store';

Testing

Unit

1. Updated tests for defaultModelImportTest
2. Added tests for postProcessOperationsWithModels

Manual

1. Ran the above expected v/s actual output comparisons to ensure the values provided are accurate

PR checklist

• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• If contributing template-only or documentation-only changes which will change sample output, build the project beforehand.
• Run the shell script ./bin/generate-samples.shto update all Petstore samples related to your fix. This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master. These must match the expectations made by your contribution. You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/java*. For Windows users, please run the script in Git BASH.
• File the PR against the correct branch: master
• Copy the technical committee to review the pull request if your PR is targeting a particular programming language.