Feature: Uploading an image to an article

  As an authenticated RenewCMS user managing the CMS
  I want to attach an image file to an existing article and get back the
  image's public location
  So that an unknown article answers 404 the same way every other article
    write does, without ever creating an orphaned image, and a disallowed
    content type is rejected with 400 before it becomes part of the
    article, without a maintainer needing to trust the client to send a
    sane file

  Background:
    Given internal/infrastructure/useCases.CreateImageUseCase.CreateImage
      already checks the uploaded content type against the allowed list
      (image/png, image/jpeg, image/webp, image/svg+xml) and the size
      against the 10485760-byte maximum before calling image.Repository.Create,
      returning image.ErrImageTypeNotAllowed or image.ErrImageTooLarge and
      calling the repository not at all when either check fails
    And internal/infrastructure/persistence's ArticleRepository.AddImage
      already returns article.ErrArticleNotFound when the article id doesn't
      match any row, and image.ErrImageNotFound when the article exists but
      the image id doesn't, both asserted with errors.Is
    And before this slice, api/handlers/image.Handler.PostImage existed and
      was wired to CreateImageUseCase and UpdateArticleUseCase.AddImage, but
      no route called it, and every error it got back from either use case
      fell through to a blanket 500
    And this slice mounts POST /v1/article/{id}/image in api/router.go, in
      the same jwtauth Verifier + Authenticator group as the other article
      write routes, and changes the upload flow so that the article's
      existence is confirmed before the image is created, so that an
      unknown article id never leaves an orphaned image behind
    And this slice changes PostImage's error handling so that errors.Is(err,
      image.ErrImageTypeNotAllowed) or errors.Is(err, image.ErrImageTooLarge)
      answers 400 with the sentinel's own message, errors.Is(err,
      article.ErrArticleNotFound) answers 404 with body
      apperr.ArticleNotFoundErrorMessage, and any other error still falls
      back to a generic 500
    And PostImage reads the uploaded file from the multipart form field
      "file"
    And on success PostImage answers 201 with a JSON body
      {"id": ..., "location": ...} holding the created image's numeric id
      and public path, e.g. "/static/uploadedImages/<stored-filename>"
    And this slice (features/remove_article_image.feature) adds the "id"
      field to that body; the id lets a client later address the image
      through DELETE /v1/article/{id}/image/{imageId}

  Scenario: Uploading an allowed image type to an existing article succeeds
    Given a valid jwt cookie for a user with id 1
    And the article repository contains an article with id 1 titled
      "Backyard Renovation Update"
    When the client sends POST /v1/article/1/image with that cookie and a
      multipart form field "file" holding a file named "before.png" with
      content type "image/png"
    Then the response status is 201
    And the response body is JSON with a "location" field whose value is
      "/static/uploadedImages/before.png"
    And the response body's "id" field equals the new image's id in the
      image repository
    And the image repository contains a new image whose Path is
      "/static/uploadedImages/before.png"
    And the article repository's article with id 1 has that new image's id
      in its Images slice

  Scenario: Uploading to an unknown article answers 404 and creates no image
    Given a valid jwt cookie for a user with id 1
    And the article repository has no article with id 9999
    When the client sends POST /v1/article/9999/image with that cookie and a
      multipart form field "file" holding a file named "before.png" with
      content type "image/png"
    Then the response status is 404
    And the response body is the text "Article not found"
    And the image repository's Create is never called
    And no image exists in the image repository

  Scenario: Uploading a disallowed content type answers 400 before the article is touched
    Given a valid jwt cookie for a user with id 1
    And the article repository contains an article with id 1 titled
      "Backyard Renovation Update"
    When the client sends POST /v1/article/1/image with that cookie and a
      multipart form field "file" holding a file named "notes.pdf" with
      content type "application/pdf"
    Then the response status is 400
    And the response body is the text
      "the file must be a PNG, JPEG, WEBP, or SVG image"
    And the image repository's Create is never called
    And the article repository's article with id 1 still has an empty
      Images slice

  Scenario: Uploading an image still requires authentication
    Given no jwt cookie is sent
    And the article repository contains an article with id 1 titled
      "Backyard Renovation Update"
    When the client sends POST /v1/article/1/image without a cookie and a
      multipart form field "file" holding a file named "before.png" with
      content type "image/png"
    Then the response status is 401
    And the image repository's Create is never called
    And the article repository's article with id 1 still has an empty
      Images slice