[elm] failed to generate map from object with additionalProperties

[mxinden]

Description

I am trying to generate an elm client based on an OpenAPI spec (see below). The spec contains a map (labelSet) represented as an object with the additionalProperties field and no properties field like described in the swagger docs.

Generating the client with the command mentioned below generates an invalid LabelSet.elm file.

openapi-generator version

$ docker run openapitools/openapi-generator-cli:latest version

3.3.0-SNAPSHOT

Image ID: acde33bd7281

OpenAPI declaration file content or url

---

swagger: '2.0'

info:
  version: 0.0.1
  title: Alertmanager API
  description: API of the Prometheus Alertmanager (https://github.com/prometheus/alertmanager)
  license:
    name: Apache 2.0
    url: http://www.apache.org/licenses/LICENSE-2.0.html

consumes:
  - "application/json"
produces:
  - "application/json"

paths:
  /alerts:
    get:
      operationId: xxx
      description: xxx
      parameters:
      responses:
        '200':
          description: xxx
          schema:
            type: array
            items:
              '$ref': '#/definitions/alert'
definitions:
  alert:
    type: object
    properties:
      labels:
        $ref: '#/definitions/labelSet'
  labelSet:
    type: object
    additionalProperties:
      type: string

Invalid output file

LabelSet.elm:

{-
   Alertmanager API
   API of the Prometheus Alertmanager (https://github.com/prometheus/alertmanager)

   OpenAPI spec version: 0.0.1

   NOTE: This file is auto generated by the openapi-generator.
   https://github.com/openapitools/openapi-generator.git
   Do not edit this file manually.
-}


module Data.LabelSet exposing (LabelSet, labelSetDecoder, labelSetEncoder)

import Json.Decode as Decode exposing (Decoder)
import Json.Decode.Pipeline exposing (optional, required)
import Json.Encode as Encode
import Maybe exposing (map, withDefault)


type alias LabelSet =
    {     }


labelSetDecoder : Decoder LabelSet
labelSetDecoder =
    Decode.succeed LabelSet



labelSetEncoder : LabelSet -> Encode.Value
labelSetEncoder model =
    Encode.object
        ]

Command line used for generation

docker run --user=1000:1000 --rm -v /home/mxinden/go/src/github.com/prometheus/alertmanager/ui/app/../..:/local openapitools/openapi-generator-cli:latest generate \                                                                                                             
        -i /local/api/v2/openapi.yaml\
        -g elm \
        --version \
        -o /local/ui/app/./openapi-STca4PUI5T

Steps to reproduce

Running elm format on the above LabelSet.elm file results in:

-- SYNTAX PROBLEM ---------------------------------------- src/Data/LabelSet.elm

I ran into something unexpected when parsing your code!

34elm-format: <stderr>: hPutChar: invalid argument (invalid character)
make: *** [Makefile:24: format] Error 1

[wing328]

@mxinden thanks for reporting the issue.

cc @trenneman

[eriktim]

@mxinden Thanks for reporting. additionalProperties has not been supported so far. This will hopefully be resolved in #1144.

[mxinden]

Thanks for the work on this @trenneman @wing328!

I have tested out the latest docker image and current master (196f122).

The generated file now properly imports Dict, but still produces an invalid elm file:

{-
   Alertmanager API
   API of the Prometheus Alertmanager (https://github.com/prometheus/alertmanager)

   OpenAPI spec version: 0.0.1

   NOTE: This file is auto generated by the openapi-generator.
   https://github.com/openapitools/openapi-generator.git
   Do not edit this file manually.
-}


module Data.LabelSet exposing (LabelSet, decoder, encoder)

import Dict exposing (Dict)
import Json.Decode as Decode exposing (Decoder)
import Json.Decode.Pipeline exposing (optional, required)
import Json.Encode as Encode


type alias LabelSet =
    {     }


decoder : Decoder LabelSet
decoder =
    Decode.succeed LabelSet



encoder : LabelSet -> Encode.Value
encoder model =
    Encode.object

        ]

Am I running off of the wrong version?

[eriktim]

@mxinden I should have mentioned the PR raised issue #1296. After that (non-Elm specific) PR the Data.LabelSet module won't be generated anymore. Already, if you do not use that module you should be fine.

[wing328]

@mxinden you can use .openapi-generator-ignore to skip LabelSet file from being generated for the time being or you can revise the definition like the following to workaround the issue:

definitions:
  alert:
    type: object
    properties:
      labels:
        type: object
        additionalProperties:
          type: string

[mxinden]

@trenneman @wing328 ah, sorry, I have overlooked the inline Dict String String definition in the parent file. Everything working fine.

I am simply deleting LabelSet.elm for now. Thanks for the pointers and the repeated help!