Merge branch 'wiki_api' into 'master'

Add API support for wiki pages

Closes #12747

See merge request !13372

8 files changed, 948 insertions, 0 deletions

diff --git a/changelogs/unreleased/wiki_api.yml b/changelogs/unreleased/wiki_api.yml
new file mode 100644
index 00000000000..9d60356aedc
--- /dev/null
+++ b/changelogs/unreleased/wiki_api.yml
@@ -0,0 +1,5 @@
+---
+title: Add API support for wiki pages
+merge_request: 13372
+author: Vitaliy @blackst0ne Klachkov
+type: added
diff --git a/doc/api/README.md b/doc/api/README.md
index db61497db53..6cbea29bda6 100644
--- a/doc/api/README.md
+++ b/doc/api/README.md
@@ -58,6 +58,7 @@ following locations:
 - [Validate CI configuration](lint.md)
 - [V3 to V4](v3_to_v4.md)
 - [Version](version.md)
+- [Wikis](wikis.md)
 
 ## Road to GraphQL
 
diff --git a/doc/api/wikis.md b/doc/api/wikis.md
new file mode 100644
index 00000000000..10eebc4a3c1
--- /dev/null
+++ b/doc/api/wikis.md
@@ -0,0 +1,157 @@
+# Wikis API
+
+> [Introduced][ce-13372] in GitLab 10.0.
+
+Available only in APIv4.
+
+## List wiki pages
+
+Get all wiki pages for a given project.
+
+```
+GET /projects/:id/wikis
+```
+
+| Attribute | Type    | Required | Description           |
+| --------- | ------- | -------- | --------------------- |
+| `id`      | integer/string    | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
+| `with_content`      | boolean    | no      | Include pages' content  |
+
+```bash
+curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v4/projects/1/wikis?with_content=1
+```
+
+Example response:
+
+```json
+[
+  {
+    "content" : "Here is an instruction how to deploy this project.",
+    "format" : "markdown",
+    "slug" : "deploy",
+    "title" : "deploy"
+  },
+  {
+    "content" : "Our development process is described here.",
+    "format" : "markdown",
+    "slug" : "development",
+    "title" : "development"
+  },{
+    "content" : "*  [Deploy](deploy)\n*  [Development](development)",
+    "format" : "markdown",
+    "slug" : "home",
+    "title" : "home"
+  }
+]
+```
+
+## Get a wiki page
+
+Get a wiki page for a given project.
+
+```
+GET /projects/:id/wikis/:slug
+```
+
+| Attribute | Type    | Required | Description           |
+| --------- | ------- | -------- | --------------------- |
+| `id`      | integer/string    | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
+| `slug` | string  | yes       | The slug (a unique string) of the wiki page |
+
+```bash
+curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v4/projects/1/wikis/home
+```
+
+Example response:
+
+```json
+[
+  {
+    "content" : "home page",
+    "format" : "markdown",
+    "slug" : "home",
+    "title" : "home"
+  }
+]
+```
+
+## Create a new wiki page
+
+Creates a new wiki page for the given repository with the given title, slug, and content.
+
+```
+POST /projects/:id/wikis
+```
+
+| Attribute     | Type    | Required | Description                  |
+| ------------- | ------- | -------- | ---------------------------- |
+| `id`      | integer/string    | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
+| `content`       | string  | yes      | The content of the wiki page |
+| `title`        | string  | yes      | The title of the wiki page        |
+| `format` | string  | no       | The format of the wiki page. Available formats are: `markdown` (default), `rdoc`, and `asciidoc` |
+
+```bash
+curl --data "format=rdoc&title=Hello&content=Hello world" --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/1/wikis"
+```
+
+Example response:
+
+```json
+{ 
+  "content" : "Hello world",
+  "format" : "markdown",
+  "slug" : "Hello",
+  "title" : "Hello"
+} 
+```
+
+## Edit an existing wiki page
+
+Updates an existing wiki page. At least one parameter is required to update the wiki page.
+
+```
+PUT /projects/:id/wikis/:slug
+```
+
+| Attribute       | Type    | Required                          | Description                      |
+| --------------- | ------- | --------------------------------- | -------------------------------  |
+| `id`      | integer/string    | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
+| `content`       | string  | yes if `title` is not provided     | The content of the wiki page |
+| `title`        | string  | yes if `content` is not provided      | The title of the wiki page        |
+| `format` | string  | no       | The format of the wiki page. Available formats are: `markdown` (default), `rdoc`, and `asciidoc` |
+| `slug` | string  | yes       | The slug (a unique string) of the wiki page |
+
+
+```bash
+curl --request PUT --data "format=rdoc&content=documentation&title=Docs" --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/1/wikis/foo"
+```
+
+Example response:
+
+```json
+{
+  "content" : "documentation",
+  "format" : "markdown",
+  "slug" : "Docs",
+  "title" : "Docs"
+}
+```
+
+## Delete a wiki page
+
+Deletes a wiki page with a given slug.
+
+```
+DELETE /projects/:id/wikis/:slug
+```
+
+| Attribute | Type    | Required | Description           |
+| --------- | ------- | -------- | --------------------- |
+| `id`      | integer/string    | yes      | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
+| `slug` | string  | yes       | The slug (a unique string) of the wiki page |
+
+```bash
+curl --request DELETE --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/1/wikis/foo"
+```
+
+On success the HTTP status code is `204` and no JSON response is expected. 
diff --git a/lib/api/api.rb b/lib/api/api.rb
index 1405a5d0f0e..d9a62bffb6d 100644
--- a/lib/api/api.rb
+++ b/lib/api/api.rb
@@ -144,6 +144,7 @@ module API
     mount ::API::Variables
     mount ::API::GroupVariables
     mount ::API::Version
+    mount ::API::Wikis
 
     route :any, '*path' do
       error!('404 Not Found', 404)
diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index 1d224d7bc21..81da2cf820b 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -1,5 +1,15 @@
 module API
   module Entities
+    class WikiPageBasic < Grape::Entity
+      expose :format
+      expose :slug
+      expose :title
+    end
+
+    class WikiPage < WikiPageBasic
+      expose :content
+    end
+
     class UserSafe < Grape::Entity
       expose :id, :name, :username
     end
diff --git a/lib/api/helpers.rb b/lib/api/helpers.rb
index e646c63467a..8b03df65ae4 100644
--- a/lib/api/helpers.rb
+++ b/lib/api/helpers.rb
@@ -56,6 +56,12 @@ module API
       @project ||= find_project!(params[:id])
     end
 
+    def wiki_page
+      page = user_project.wiki.find_page(params[:slug])
+
+      page || not_found!('Wiki Page')
+    end
+
     def available_labels
       @available_labels ||= LabelsFinder.new(current_user, project_id: user_project.id).execute
     end
diff --git a/lib/api/wikis.rb b/lib/api/wikis.rb
new file mode 100644
index 00000000000..b3fc4e876ad
--- /dev/null
+++ b/lib/api/wikis.rb
@@ -0,0 +1,89 @@
+module API
+  class Wikis < Grape::API
+    helpers do
+      params :wiki_page_params do
+        requires :content, type: String, desc: 'Content of a wiki page'
+        requires :title, type: String, desc: 'Title of a wiki page'
+        optional :format,
+          type: String,
+          values: ProjectWiki::MARKUPS.values.map(&:to_s),
+          default: 'markdown',
+          desc: 'Format of a wiki page. Available formats are markdown, rdoc, and asciidoc'
+      end
+    end
+
+    resource :projects, requirements: API::PROJECT_ENDPOINT_REQUIREMENTS do
+      desc 'Get a list of wiki pages' do
+        success Entities::WikiPageBasic
+      end
+      params do
+        optional :with_content, type: Boolean, default: false, desc: "Include pages' content"
+      end
+      get ':id/wikis' do
+        authorize! :read_wiki, user_project
+
+        entity = params[:with_content] ? Entities::WikiPage : Entities::WikiPageBasic
+        present user_project.wiki.pages, with: entity
+      end
+
+      desc 'Get a wiki page' do
+        success Entities::WikiPage
+      end
+      params do
+        requires :slug, type: String, desc: 'The slug of a wiki page'
+      end
+      get ':id/wikis/:slug' do
+        authorize! :read_wiki, user_project
+
+        present wiki_page, with: Entities::WikiPage
+      end
+
+      desc 'Create a wiki page' do
+        success Entities::WikiPage
+      end
+      params do
+        use :wiki_page_params
+      end
+      post ':id/wikis' do
+        authorize! :create_wiki, user_project
+
+        page = WikiPages::CreateService.new(user_project, current_user, params).execute
+
+        if page.valid?
+          present page, with: Entities::WikiPage
+        else
+          render_validation_error!(page)
+        end
+      end
+
+      desc 'Update a wiki page' do
+        success Entities::WikiPage
+      end
+      params do
+        use :wiki_page_params
+      end
+      put ':id/wikis/:slug' do
+        authorize! :create_wiki, user_project
+
+        page = WikiPages::UpdateService.new(user_project, current_user, params).execute(wiki_page)
+
+        if page.valid?
+          present page, with: Entities::WikiPage
+        else
+          render_validation_error!(page)
+        end
+      end
+
+      desc 'Delete a wiki page'
+      params do
+        requires :slug, type: String, desc: 'The slug of a wiki page'
+      end
+      delete ':id/wikis/:slug' do
+        authorize! :admin_wiki, user_project
+
+        status 204
+        WikiPages::DestroyService.new(user_project, current_user).execute(wiki_page)
+      end
+    end
+  end
+end
diff --git a/spec/requests/api/wikis_spec.rb b/spec/requests/api/wikis_spec.rb
new file mode 100644
index 00000000000..9e889d1eecf
--- /dev/null
+++ b/spec/requests/api/wikis_spec.rb
@@ -0,0 +1,679 @@
+require 'spec_helper'
+
+# For every API endpoint we test 3 states of wikis:
+# - disabled
+# - enabled only for team members
+# - enabled for everyone who has access
+# Every state is tested for 3 user roles:
+# - guest
+# - developer
+# - master
+# because they are 3 edge cases of using wiki pages.
+
+describe API::Wikis do
+  let(:user) { create(:user) }
+  let(:payload) { { content: 'content', format: 'rdoc', title: 'title' } }
+  let(:expected_keys_with_content) { %w(content format slug title) }
+  let(:expected_keys_without_content) { %w(format slug title) }
+
+  shared_examples_for 'returns list of wiki pages' do
+    context 'when wiki has pages' do
+      let!(:pages) do
+        [create(:wiki_page, wiki: project.wiki, attrs: { title: 'page1', content: 'content of page1' }),
+         create(:wiki_page, wiki: project.wiki, attrs: { title: 'page2', content: 'content of page2' })]
+      end
+
+      it 'returns the list of wiki pages without content' do
+        get api(url, user)
+
+        expect(response).to have_http_status(200)
+        expect(json_response.size).to eq(2)
+
+        json_response.each_with_index do |page, index|
+          expect(page.keys).to match_array(expected_keys_without_content)
+          expect(page['slug']).to eq(pages[index].slug)
+          expect(page['title']).to eq(pages[index].title)
+        end
+      end
+
+      it 'returns the list of wiki pages with content' do
+        get api(url, user), with_content: 1
+
+        expect(response).to have_http_status(200)
+        expect(json_response.size).to eq(2)
+
+        json_response.each_with_index do |page, index|
+          expect(page.keys).to match_array(expected_keys_with_content)
+          expect(page['content']).to eq(pages[index].content)
+          expect(page['slug']).to eq(pages[index].slug)
+          expect(page['title']).to eq(pages[index].title)
+        end
+      end
+    end
+
+    it 'return the empty list of wiki pages' do
+      get api(url, user)
+
+      expect(response).to have_http_status(200)
+      expect(json_response.size).to eq(0)
+    end
+  end
+
+  shared_examples_for 'returns wiki page' do
+    it 'returns the wiki page' do
+      expect(response).to have_http_status(200)
+      expect(json_response.size).to eq(4)
+      expect(json_response.keys).to match_array(expected_keys_with_content)
+      expect(json_response['content']).to eq(page.content)
+      expect(json_response['slug']).to eq(page.slug)
+      expect(json_response['title']).to eq(page.title)
+    end
+  end
+
+  shared_examples_for 'creates wiki page' do
+    it 'creates the wiki page' do
+      post(api(url, user), payload)
+
+      expect(response).to have_http_status(201)
+      expect(json_response.size).to eq(4)
+      expect(json_response.keys).to match_array(expected_keys_with_content)
+      expect(json_response['content']).to eq(payload[:content])
+      expect(json_response['slug']).to eq(payload[:title].tr(' ', '-'))
+      expect(json_response['title']).to eq(payload[:title])
+      expect(json_response['rdoc']).to eq(payload[:rdoc])
+    end
+
+    [:title, :content].each do |part|
+      it "responds with validation error on empty #{part}" do
+        payload.delete(part)
+
+        post(api(url, user), payload)
+
+        expect(response).to have_http_status(400)
+        expect(json_response.size).to eq(1)
+        expect(json_response['error']).to eq("#{part} is missing")
+      end
+    end
+  end
+
+  shared_examples_for 'updates wiki page' do
+    it 'updates the wiki page' do
+      expect(response).to have_http_status(200)
+      expect(json_response.size).to eq(4)
+      expect(json_response.keys).to match_array(expected_keys_with_content)
+      expect(json_response['content']).to eq(payload[:content])
+      expect(json_response['slug']).to eq(payload[:title].tr(' ', '-'))
+      expect(json_response['title']).to eq(payload[:title])
+    end
+  end
+
+  shared_examples_for '403 Forbidden' do
+    it 'returns 403 Forbidden' do
+      expect(response).to have_http_status(403)
+      expect(json_response.size).to eq(1)
+      expect(json_response['message']).to eq('403 Forbidden')
+    end
+  end
+
+  shared_examples_for '404 Wiki Page Not Found' do
+    it 'returns 404 Wiki Page Not Found' do
+      expect(response).to have_http_status(404)
+      expect(json_response.size).to eq(1)
+      expect(json_response['message']).to eq('404 Wiki Page Not Found')
+    end
+  end
+
+  shared_examples_for '404 Project Not Found' do
+    it 'returns 404 Project Not Found' do
+      expect(response).to have_http_status(404)
+      expect(json_response.size).to eq(1)
+      expect(json_response['message']).to eq('404 Project Not Found')
+    end
+  end
+
+  shared_examples_for '204 No Content' do
+    it 'returns 204 No Content' do
+      expect(response).to have_http_status(204)
+    end
+  end
+
+  describe 'GET /projects/:id/wikis' do
+    let(:url) { "/projects/#{project.id}/wikis" }
+
+    context 'when wiki is disabled' do
+      let(:project) { create(:project, :wiki_disabled) }
+
+      context 'when user is guest' do
+        before do
+          get api(url)
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+
+          get api(url, user)
+        end
+
+        include_examples '403 Forbidden'
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+
+          get api(url, user)
+        end
+
+        include_examples '403 Forbidden'
+      end
+    end
+
+    context 'when wiki is available only for team members' do
+      let(:project) { create(:project, :wiki_private) }
+
+      context 'when user is guest' do
+        before do
+          get api(url)
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+        end
+
+        include_examples 'returns list of wiki pages'
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+        end
+
+        include_examples 'returns list of wiki pages'
+      end
+    end
+
+    context 'when wiki is available for everyone with access' do
+      let(:project) { create(:project) }
+
+      context 'when user is guest' do
+        before do
+          get api(url)
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+        end
+
+        include_examples 'returns list of wiki pages'
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+        end
+
+        include_examples 'returns list of wiki pages'
+      end
+    end
+  end
+
+  describe 'GET /projects/:id/wikis/:slug' do
+    let(:page) { create(:wiki_page, wiki: project.wiki) }
+    let(:url) { "/projects/#{project.id}/wikis/#{page.slug}" }
+
+    context 'when wiki is disabled' do
+      let(:project) { create(:project, :wiki_disabled) }
+
+      context 'when user is guest' do
+        before do
+          get api(url)
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+
+          get api(url, user)
+        end
+
+        include_examples '403 Forbidden'
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+
+          get api(url, user)
+        end
+
+        include_examples '403 Forbidden'
+      end
+    end
+
+    context 'when wiki is available only for team members' do
+      let(:project) { create(:project, :wiki_private) }
+
+      context 'when user is guest' do
+        before do
+          get api(url)
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+          get api(url, user)
+        end
+
+        include_examples 'returns wiki page'
+
+        context 'when page is not existing' do
+          let(:url) { "/projects/#{project.id}/wikis/unknown" }
+
+          include_examples '404 Wiki Page Not Found'
+        end
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+
+          get api(url, user)
+        end
+
+        include_examples 'returns wiki page'
+
+        context 'when page is not existing' do
+          let(:url) { "/projects/#{project.id}/wikis/unknown" }
+
+          include_examples '404 Wiki Page Not Found'
+        end
+      end
+    end
+
+    context 'when wiki is available for everyone with access' do
+      let(:project) { create(:project) }
+
+      context 'when user is guest' do
+        before do
+          get api(url)
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+
+          get api(url, user)
+        end
+
+        include_examples 'returns wiki page'
+
+        context 'when page is not existing' do
+          let(:url) { "/projects/#{project.id}/wikis/unknown" }
+
+          include_examples '404 Wiki Page Not Found'
+        end
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+
+          get api(url, user)
+        end
+
+        include_examples 'returns wiki page'
+
+        context 'when page is not existing' do
+          let(:url) { "/projects/#{project.id}/wikis/unknown" }
+
+          include_examples '404 Wiki Page Not Found'
+        end
+      end
+    end
+  end
+
+  describe 'POST /projects/:id/wikis' do
+    let(:payload) { { title: 'title', content: 'content' } }
+    let(:url) { "/projects/#{project.id}/wikis" }
+
+    context 'when wiki is disabled' do
+      let(:project) { create(:project, :wiki_disabled) }
+
+      context 'when user is guest' do
+        before do
+          post(api(url), payload)
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+          post(api(url, user), payload)
+        end
+
+        include_examples '403 Forbidden'
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+          post(api(url, user), payload)
+        end
+
+        include_examples '403 Forbidden'
+      end
+    end
+
+    context 'when wiki is available only for team members' do
+      let(:project) { create(:project, :wiki_private) }
+
+      context 'when user is guest' do
+        before do
+          post(api(url), payload)
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+        end
+
+        include_examples 'creates wiki page'
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+        end
+
+        include_examples 'creates wiki page'
+      end
+    end
+
+    context 'when wiki is available for everyone with access' do
+      let(:project) { create(:project) }
+
+      context 'when user is guest' do
+        before do
+          post(api(url), payload)
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+        end
+
+        include_examples 'creates wiki page'
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+        end
+
+        include_examples 'creates wiki page'
+      end
+    end
+  end
+
+  describe 'PUT /projects/:id/wikis/:slug' do
+    let(:page) { create(:wiki_page, wiki: project.wiki) }
+    let(:payload) { { title: 'new title', content: 'new content' } }
+    let(:url) { "/projects/#{project.id}/wikis/#{page.slug}" }
+
+    context 'when wiki is disabled' do
+      let(:project) { create(:project, :wiki_disabled) }
+
+      context 'when user is guest' do
+        before do
+          put(api(url), payload)
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+
+          put(api(url, user), payload)
+        end
+
+        include_examples '403 Forbidden'
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+
+          put(api(url, user), payload)
+        end
+
+        include_examples '403 Forbidden'
+      end
+    end
+
+    context 'when wiki is available only for team members' do
+      let(:project) { create(:project, :wiki_private) }
+
+      context 'when user is guest' do
+        before do
+          put(api(url), payload)
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+
+          put(api(url, user), payload)
+        end
+
+        include_examples 'updates wiki page'
+
+        context 'when page is not existing' do
+          let(:url) { "/projects/#{project.id}/wikis/unknown" }
+
+          include_examples '404 Wiki Page Not Found'
+        end
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+
+          put(api(url, user), payload)
+        end
+
+        include_examples 'updates wiki page'
+
+        context 'when page is not existing' do
+          let(:url) { "/projects/#{project.id}/wikis/unknown" }
+
+          include_examples '404 Wiki Page Not Found'
+        end
+      end
+    end
+
+    context 'when wiki is available for everyone with access' do
+      let(:project) { create(:project) }
+
+      context 'when user is guest' do
+        before do
+          put(api(url), payload)
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+
+          put(api(url, user), payload)
+        end
+
+        include_examples 'updates wiki page'
+
+        context 'when page is not existing' do
+          let(:url) { "/projects/#{project.id}/wikis/unknown" }
+
+          include_examples '404 Wiki Page Not Found'
+        end
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+
+          put(api(url, user), payload)
+        end
+
+        include_examples 'updates wiki page'
+
+        context 'when page is not existing' do
+          let(:url) { "/projects/#{project.id}/wikis/unknown" }
+
+          include_examples '404 Wiki Page Not Found'
+        end
+      end
+    end
+  end
+
+  describe 'DELETE /projects/:id/wikis/:slug' do
+    let(:page) { create(:wiki_page, wiki: project.wiki) }
+    let(:url) { "/projects/#{project.id}/wikis/#{page.slug}" }
+
+    context 'when wiki is disabled' do
+      let(:project) { create(:project, :wiki_disabled) }
+
+      context 'when user is guest' do
+        before do
+          delete(api(url))
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+
+          delete(api(url, user))
+        end
+
+        include_examples '403 Forbidden'
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+
+          delete(api(url, user))
+        end
+
+        include_examples '403 Forbidden'
+      end
+    end
+
+    context 'when wiki is available only for team members' do
+      let(:project) { create(:project, :wiki_private) }
+
+      context 'when user is guest' do
+        before do
+          delete(api(url))
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+
+          delete(api(url, user))
+        end
+
+        include_examples '403 Forbidden'
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+
+          delete(api(url, user))
+        end
+
+        include_examples '204 No Content'
+      end
+    end
+
+    context 'when wiki is available for everyone with access' do
+      let(:project) { create(:project) }
+
+      context 'when user is guest' do
+        before do
+          delete(api(url))
+        end
+
+        include_examples '404 Project Not Found'
+      end
+
+      context 'when user is developer' do
+        before do
+          project.add_developer(user)
+
+          delete(api(url, user))
+        end
+
+        include_examples '403 Forbidden'
+      end
+
+      context 'when user is master' do
+        before do
+          project.add_master(user)
+
+          delete(api(url, user))
+        end
+
+        include_examples '204 No Content'
+
+        context 'when page is not existing' do
+          let(:url) { "/projects/#{project.id}/wikis/unknown" }
+
+          include_examples '404 Wiki Page Not Found'
+        end
+      end
+    end
+  end
+end