[Go] Parse integer array query parameters. Fix typos

[aliakseiz]

*Affects the Go-server only.

Limited support of integer array parameters in a query

Adds a code generation to parse query parameter fields of int32 array and int64 array types. Assumes that style: form and explode: false are used as serialization method.

openapi: "3.0.0"
info:
  description: Example API
  version: 1.0.0
  title: "Example API"

servers:
  - url: http://localhost:8080/api/v1
    description: development server

paths:
  /companies:
    get:
      summary: Filter companies by specified criteria
      operationId: find
      parameters:
        - name: ids
          in: query
          example: "500, 501"
          schema:
            type: array
            items:
              type: integer
              format: int64
      tags:
        - Company
      responses:
        200:
          description: Successful operation

Before:

parentIDsParam := strings.Split(query.Get("ids"), ",")

After:

mtinfoIDsParam, err := parseInt64ArrayParameter(query.Get("ids"), ",", false)
if err != nil {
	c.errorHandler(w, r, &ParsingError{Err: err}, nil)
	return
}

Other

Fixes minor typos in comments.

Technical committee

@antihax @grokify @kemokemo @jirikuncar @ph4r5h4d

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[wing328]

Thanks for the PR. If I understand this correctly, this PR is more bug fixes so it can target current master unless there're breaking changes (without fallback) that I'm not aware of.

[aliakseiz]

Thanks for the PR. If I understand this correctly, this PR is more bug fixes so it can target current master unless there're breaking changes (without fallback) that I'm not aware of.

Thanks for review. Indeed there are no breaking changes, it just extends the existing functionality. But it uses some functions, which are not present in master yet (e.g. parseInt64ArrayParameter from here).

Left it in a draft state (forgot about the [WIP] though), because I have some doubts about serialization: changes suggested in this PR will generate expected result only for explode: false.

According to OpenAPI specification v3.1 the default style for query parameters is form (link) and default explode value is true (link).
But DefaultCodegen.java sets it to false, unless specified explicitly (link).

Looking at the *.mustache templates I noticed that Go implementation doesn't use the isExplode attribute. In fact, very few implementations for other languages do.

Coming back to the point, in case explode will be true, generated output will not work as expected, but it will compile at least. Actually, latest master build produces erroneous code even, when query parameter type is array of integers.

I would appreciate if somebody could approve this PR taking the aforementioned limitation into consideration.

[wing328]

Thanks for the PR but your commit (as shown in the Commits tab) is not linked to your Github account, which means this PR won't count as your contribution in https://github.com/OpenAPITools/openapi-generator/graphs/contributors.

Let me know if you need help fixing it.

Ref: https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-can-i-update-commits-that-are-not-linked-to-my-github-account

[aliakseiz]

@wing328 thanks for noticing.
Now my email is linked to a Github account.

[wing328]

CircleCI failure (already fixed in the master) not related to this change.

[wing328]

CircleCI tests passed via https://app.circleci.com/pipelines/github/OpenAPITools/openapi-generator?branch=aliakseiz-go%2Fint-arrays-in-query&filter=all