Support preview_markdown action for personal_snippets

app/controllers/concerns/markdown_preview.rb

+module MarkdownPreview
+  private
+
+  def render_markdown_preview(text, markdown_context = {})
+    render json: {
+      body: view_context.markdown(text, markdown_context),
+      references: {
+        users: preview_referenced_users(text)
+      }
+    }
+  end
+
+  def preview_referenced_users(text)
+    extractor = Gitlab::ReferenceExtractor.new(@project, current_user)
+    extractor.analyze(text, author: current_user)
+
+    extractor.users.map(&:username)
+  end
+end

app/controllers/projects/wikis_controller.rb

 class Projects::WikisController < Projects::ApplicationController
+  include MarkdownPreview
+
   before_action :authorize_read_wiki!
   before_action :authorize_create_wiki!, only: [:edit, :create, :history]
   before_action :authorize_admin_wiki!, only: :destroy
@@ -91,21 +93,13 @@ class Projects::WikisController < Projects::ApplicationController
     )
   end
-  def preview_markdown
-    text = params[:text]
-
-    ext = Gitlab::ReferenceExtractor.new(@project, current_user)
-    ext.analyze(text, author: current_user)
-
-    render json: {
-      body: view_context.markdown(text, pipeline: :wiki, project_wiki: @project_wiki, page_slug: params[:id]),
-      references: {
-        users: ext.users.map(&:username)
-      }
-    }
+  def git_access
   end
-  def git_access
+  def preview_markdown
+    context = { pipeline: :wiki, project_wiki: @project_wiki, page_slug: params[:id] }
+
+    render_markdown_preview(params[:text], context)
   end
   private
@@ -115,7 +109,6 @@ class Projects::WikisController < Projects::ApplicationController
     # Call #wiki to make sure the Wiki Repo is initialized
     @project_wiki.wiki
-
     @sidebar_wiki_entries = WikiPage.group_by_directory(@project_wiki.pages.first(15))
   rescue ProjectWiki::CouldNotCreateWikiError
     flash[:notice] = "Could not create Wiki Repository at this time. Please try again later."

app/controllers/projects_controller.rb

 class ProjectsController < Projects::ApplicationController
   include IssuableCollections
   include ExtractsPath
+  include MarkdownPreview
   before_action :authenticate_user!, except: [:index, :show, :activity, :refs]
   before_action :project, except: [:index, :new, :create]
@@ -216,20 +217,6 @@ class ProjectsController < Projects::ApplicationController
     }
   end
-  def preview_markdown
-    text = params[:text]
-
-    ext = Gitlab::ReferenceExtractor.new(@project, current_user)
-    ext.analyze(text, author: current_user)
-
-    render json: {
-      body:       view_context.markdown(text),
-      references: {
-        users: ext.users.map(&:username)
-      }
-    }
-  end
-
   def refs
     branches = BranchesFinder.new(@repository, params).execute.map(&:name)
@@ -252,6 +239,10 @@ class ProjectsController < Projects::ApplicationController
     render json: options.to_json
   end
+  def preview_markdown
+    render_markdown_preview(params[:text])
+  end
+
   private
   # Render project landing depending of which features are available

app/controllers/snippets_controller.rb

@@ -2,6 +2,7 @@ class SnippetsController < ApplicationController
   include ToggleAwardEmoji
   include SpammableActions
   include SnippetsActions
+  include MarkdownPreview
   before_action :snippet, only: [:show, :edit, :destroy, :update, :raw, :download]
@@ -77,6 +78,10 @@ class SnippetsController < ApplicationController
     )
   end
+  def preview_markdown
+    render_markdown_preview(params[:text], skip_project_check: true)
+  end
+
   protected
   def snippet

app/helpers/gitlab_markdown_helper.rb

@@ -196,7 +196,7 @@ module GitlabMarkdownHelper
   end
   # Calls Banzai.post_process with some common context options
-  def banzai_postprocess(html, context)
+  def banzai_postprocess(html, context = {})
     context.merge!(
       current_user:   (current_user if defined?(current_user)),

changelogs/unreleased/12910-personal-snippet-prep-2.yml

+---
+title: Support Markdown previews for personal snippets
+merge_request: 10810
+author:

config/routes/snippets.rb

@@ -3,6 +3,7 @@ resources :snippets, concerns: :awardable do
     get 'raw'
     get 'download'
     post :mark_as_spam
+    post :preview_markdown
   end
 end

spec/controllers/projects/wikis_controller_spec.rb

+require 'spec_helper'
+
+describe Projects::WikisController do
+  let(:project) { create(:project_empty_repo, :public) }
+  let(:user) { create(:user) }
+
+  describe 'POST #preview_markdown' do
+    it 'renders json in a correct format' do
+      sign_in(user)
+
+      post :preview_markdown, namespace_id: project.namespace, project_id: project, id: 'page/path', text: '*Markdown* text'
+
+      expect(JSON.parse(response.body).keys).to match_array(%w(body references))
+    end
+  end
+end

spec/controllers/projects_controller_spec.rb

@@ -398,4 +398,14 @@ describe ProjectsController do
       expect(parsed_body["Commits"]).to include("123456")
     end
   end
+
+  describe 'POST #preview_markdown' do
+    it 'renders json in a correct format' do
+      sign_in(user)
+
+      post :preview_markdown, namespace_id: public_project.namespace, id: public_project, text: '*Markdown* text'
+
+      expect(JSON.parse(response.body).keys).to match_array(%w(body references))
+    end
+  end
 end

spec/controllers/snippets_controller_spec.rb

@@ -521,4 +521,16 @@ describe SnippetsController do
       end
     end
   end
+
+  describe 'POST #preview_markdown' do
+    let(:snippet) { create(:personal_snippet, :public) }
+
+    it 'renders json in a correct format' do
+      sign_in(user)
+
+      post :preview_markdown, id: snippet, text: '*Markdown* text'
+
+      expect(JSON.parse(response.body).keys).to match_array(%w(body references))
+    end
+  end
 end