refac: authenticated user can edit an article's body; an unknown id returns 404

features/edit_article_body.feature

@@ -0,0 +1,103 @@
+Feature: An authenticated user can edit an article's body
+
+  As an authenticated RenewCMS user managing the CMS
+  I want to change an existing article's body from an HTTP endpoint
+  So that a published or draft article's content can be corrected or updated without
+    deleting and recreating it
+
+  Background:
+    Given internal/domain/article.Repository already exposes
+      UpdateBody(id uint32, body string) (Article, error), and
+      UpdateArticleUseCase.UpdateBody delegates to it unchanged
+    And UpdateArticleUseCase is already built in api/dependecyInjection.go as
+      container.UpdateArticleUseCase, but before this slice no handler or route calls
+      UpdateBody
+    And this slice adds Handler.UpdateArticleBody, backed by
+      UpdateArticleUseCase.UpdateBody(id, body)
+    And this slice mounts PATCH /v1/article/{id} inside the same jwtauth Verifier +
+      Authenticator group as GET /v1/article/{id}, POST /v1/article/,
+      DELETE /v1/article/{id}, PATCH /v1/article/{id}/publish and
+      PATCH /v1/article/{id}/unpublish in api/router.go, so it also requires a valid
+      jwt cookie
+    And the request body is JSON {"body": "..."}, validated with
+      validate:"required,max=10000" on the Body field, the same tag PostArticle.Body
+      already carries
+    And a successful edit answers 200 with the JSON body of the updated article.Article,
+      the same shape GetArticle, PostArticle, PublishArticle and UnpublishArticle
+      already return; the article's title, is_online flag and images are unchanged
+    And an id that does not parse as a uint32 answers 400 with body
+      apperr.IdUint32ErrorMessage, the same as GetArticle, DeleteArticle,
+      PublishArticle and UnpublishArticle
+    And a body that is not valid JSON answers 400 with body apperr.BodyErrorMessage,
+      the same as PostArticle
+    And a body that fails its own required/max=10000 validation answers 400 with the
+      raw validator error text, the same as PostArticle already does for its own
+      fields; no new apperr message is introduced for this
+    And an id absent from the article repository answers 404 with body
+      apperr.ArticleNotFoundErrorMessage, backed by
+      errors.Is(err, article.ErrArticleNotFound), the same as DeleteArticle,
+      PublishArticle and UnpublishArticle already do per
+      features/write_not_found_errors.feature
+    And this slice does not add any way to change an article's title after creation,
+      per features/article_title_rules.feature
+
+  Scenario: Editing an existing article's body updates only the body
+    Given a valid jwt cookie for a user with id 1
+    And the article repository contains an online article titled
+      "Backyard Renovation Update" with id 1 and body "Old body text"
+    When the client sends PATCH /v1/article/1 with that cookie and body
+      {"body": "New body text"}
+    Then the response status is 200
+    And the response body is the article with id 1, "body": "New body text",
+      "title": "Backyard Renovation Update" and "is_online": true
+
+  Scenario: Editing an offline article's body leaves it offline
+    Given a valid jwt cookie for a user with id 1
+    And the article repository contains an offline article titled
+      "Draft: Kitchen Remodel" with id 2 and body "Draft notes"
+    When the client sends PATCH /v1/article/2 with that cookie and body
+      {"body": "Revised draft notes"}
+    Then the response status is 200
+    And the response body is the article with id 2, "body": "Revised draft notes"
+      and "is_online": false
+
+  Scenario: Editing an unknown article answers 404
+    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 PATCH /v1/article/9999 with that cookie and body
+      {"body": "New body text"}
+    Then the response status is 404
+    And the response body is the text "Article not found"
+
+  Scenario: A malformed id answers 400 before any repository call
+    Given a valid jwt cookie for a user with id 1
+    When the client sends PATCH /v1/article/not-a-number with that cookie and body
+      {"body": "New body text"}
+    Then the response status is 400
+    And the response body is the text apperr.IdUint32ErrorMessage
+
+  Scenario: A non-JSON request body answers 400 with the body error message
+    Given a valid jwt cookie for a user with id 1
+    And the article repository contains an article with id 1
+    When the client sends PATCH /v1/article/1 with that cookie and a body that is not
+      valid JSON
+    Then the response status is 400
+    And the response body is the text apperr.BodyErrorMessage
+
+  Scenario Outline: A body value that fails validation answers 400
+    Given a valid jwt cookie for a user with id 1
+    And the article repository contains an article with id 1
+    When the client sends PATCH /v1/article/1 with that cookie and body <payload>
+    Then the response status is 400
+
+    Examples:
+      | payload                              |
+      | {"body": ""}                         |
+      | {"body": "<10001-character string>"} |
+
+  Scenario: Editing an article requires authentication
+    Given no jwt cookie is sent
+    And the article repository contains an article with id 1
+    When the client sends PATCH /v1/article/1 without a cookie and body
+      {"body": "New body text"}
+    Then the response status is 401