API: Endpoint to expose personal snippets as /snippets

Adding the necessary API for the new /snippets Restful resource
added with this commit. Added a new Grape class `Snippets`, as
well as a `PersonalSnippet` entity.

Issue: #20042
Merge-Request: !6373
Signed-off-by: Guyzmo <guyzmo+gitlab+pub@m0g.net>

11 files changed, 594 insertions, 26 deletions

diff --git a/app/finders/snippets_finder.rb b/app/finders/snippets_finder.rb
index 00ff1611039..0586a923a74 100644
--- a/app/finders/snippets_finder.rb
+++ b/app/finders/snippets_finder.rb
@@ -1,12 +1,15 @@
 class SnippetsFinder
   def execute(current_user, params = {})
     filter = params[:filter]
+    user = params.fetch(:user, current_user)
 
     case filter
     when :all then
       snippets(current_user).fresh
+    when :public then
+      Snippet.are_public.fresh
     when :by_user then
-      by_user(current_user, params[:user], params[:scope])
+      by_user(current_user, user, params[:scope])
     when :by_project
       by_project(current_user, params[:project])
     end
diff --git a/app/helpers/gitlab_routing_helper.rb b/app/helpers/gitlab_routing_helper.rb
index af9087d8326..99db73c9ee0 100644
--- a/app/helpers/gitlab_routing_helper.rb
+++ b/app/helpers/gitlab_routing_helper.rb
@@ -159,6 +159,11 @@ module GitlabRoutingHelper
     resend_invite_namespace_project_project_member_path(project_member.source.namespace, project_member.source, project_member)
   end
 
+  # Snippets
+  def personal_snippet_url(snippet, *args)
+    snippet_url(snippet)
+  end
+
   # Groups
 
   ## Members
diff --git a/app/policies/personal_snippet_policy.rb b/app/policies/personal_snippet_policy.rb
index 46c5aa1a5be..d3913986cd8 100644
--- a/app/policies/personal_snippet_policy.rb
+++ b/app/policies/personal_snippet_policy.rb
@@ -6,9 +6,14 @@ class PersonalSnippetPolicy < BasePolicy
     if @subject.author == @user
       can! :read_personal_snippet
       can! :update_personal_snippet
+      can! :destroy_personal_snippet
       can! :admin_personal_snippet
     end
 
+    unless @user.external?
+      can! :create_personal_snippet
+    end
+
     if @subject.internal? && !@user.external?
       can! :read_personal_snippet
     end
diff --git a/changelogs/unreleased/features-api-snippets.yml b/changelogs/unreleased/features-api-snippets.yml
new file mode 100644
index 00000000000..80c7bb75359
--- /dev/null
+++ b/changelogs/unreleased/features-api-snippets.yml
@@ -0,0 +1,4 @@
+---
+title: 'API: Endpoint to expose personal snippets as /snippets'
+merge_request: 6373
+author: Bernard Guyzmo Pratz
diff --git a/doc/api/snippets.md b/doc/api/snippets.md
new file mode 100644
index 00000000000..5a5dc162ffe
--- /dev/null
+++ b/doc/api/snippets.md
@@ -0,0 +1,232 @@
+# Snippets
+
+> [Introduced][ce-6373] in GitLab 8.15.
+
+### Snippet visibility level
+
+Snippets in GitLab can be either private, internal, or public.
+You can set it with the `visibility_level` field in the snippet.
+
+Constants for snippet visibility levels are:
+
+| Visibility | Visibility level | Description |
+| ---------- | ---------------- | ----------- |
+| Private    | `0`  | The snippet is visible only to the snippet creator |
+| Internal   | `10` | The snippet is visible for any logged in user |
+| Public     | `20` | The snippet can be accessed without any authentication |
+
+## List snippets
+
+Get a list of current user's snippets.
+
+```
+GET /snippets
+```
+
+## Single snippet
+
+Get a single snippet.
+
+```
+GET /snippets/:id
+```
+
+Parameters:
+
+| Attribute          | Type    | Required | Description                   |
+| ---------          | ----    | -------- | -----------                   |
+| `id`               | Integer | yes      | The ID of a snippet           |
+
+``` bash
+curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/snippets/1
+```
+
+Example response:
+
+``` json
+{
+  "id": 1,
+  "title": "test",
+  "file_name": "add.rb",
+  "author": {
+    "id": 1,
+    "username": "john_smith",
+    "email": "john@example.com",
+    "name": "John Smith",
+    "state": "active",
+    "created_at": "2012-05-23T08:00:58Z"
+  },
+  "expires_at": null,
+  "updated_at": "2012-06-28T10:52:04Z",
+  "created_at": "2012-06-28T10:52:04Z",
+  "web_url": "http://example.com/snippets/1",
+}
+```
+
+## Create new snippet
+
+Creates a new snippet. The user must have permission to create new snippets.
+
+```
+POST /snippets
+```
+
+Parameters:
+
+| Attribute          | Type    | Required | Description                |
+| ---------          | ----    | -------- | -----------                |
+| `title`            | String  | yes      | The title of a snippet     |
+| `file_name`        | String  | yes      | The name of a snippet file |
+| `content`          | String  | yes      | The content of a snippet   |
+| `visibility_level` | Integer | yes      | The snippet's visibility   |
+
+
+``` bash
+curl --request POST --data '{"title": "This is a snippet", "content": "Hello world", "file_name": "test.txt", "visibility_level": 10 }' --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/snippets
+```
+
+Example response:
+
+``` json
+{
+  "id": 1,
+  "title": "This is a snippet",
+  "file_name": "test.txt",
+  "author": {
+    "id": 1,
+    "username": "john_smith",
+    "email": "john@example.com",
+    "name": "John Smith",
+    "state": "active",
+    "created_at": "2012-05-23T08:00:58Z"
+  },
+  "expires_at": null,
+  "updated_at": "2012-06-28T10:52:04Z",
+  "created_at": "2012-06-28T10:52:04Z",
+  "web_url": "http://example.com/snippets/1",
+}
+```
+
+## Update snippet
+
+Updates an existing snippet. The user must have permission to change an existing snippet.
+
+```
+PUT /snippets/:id
+```
+
+Parameters:
+
+| Attribute          | Type    | Required | Description                |
+| ---------          | ----    | -------- | -----------                |
+| `id`               | Integer | yes      | The ID of a snippet        |
+| `title`            | String  | no       | The title of a snippet     |
+| `file_name`        | String  | no       | The name of a snippet file |
+| `content`          | String  | no       | The content of a snippet   |
+| `visibility_level` | Integer | no       | The snippet's visibility   |
+
+
+``` bash
+curl --request PUT --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" --data '{"title": "foo", "content": "bar"}' https://gitlab.example.com/api/v3/snippets/1
+```
+
+Example response:
+
+``` json
+{
+  "id": 1,
+  "title": "test",
+  "file_name": "add.rb",
+  "author": {
+    "id": 1,
+    "username": "john_smith",
+    "email": "john@example.com",
+    "name": "John Smith",
+    "state": "active",
+    "created_at": "2012-05-23T08:00:58Z"
+  },
+  "expires_at": null,
+  "updated_at": "2012-06-28T10:52:04Z",
+  "created_at": "2012-06-28T10:52:04Z",
+  "web_url": "http://example.com/snippets/1",
+}
+```
+
+## Delete snippet
+
+Deletes an existing snippet. 
+
+```
+DELETE /snippets/:id
+```
+
+Parameters:
+
+| Attribute          | Type    | Required | Description                   |
+| ---------          | ----    | -------- | -----------                   |
+| `id`               | Integer | yes      | The ID of a snippet           |
+
+
+```
+curl --request DELETE --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v3/snippets/1"
+```
+
+upon successful delete a `204 No content` HTTP code shall be expected, with no data,
+but if the snippet is non-existent, a `404 Not Found` will be returned.
+
+## Explore all public snippets
+
+```
+GET /snippets/public
+```
+
+| Attribute  | Type    | Required | Description                           |
+| ---------  | ----    | -------- | -----------                           |
+| `per_page` | Integer | no       | number of snippets to return per page |
+| `page`     | Integer | no       | the page to retrieve                  |
+
+``` bash
+curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/snippets/public?per_page=2&page=1
+```
+
+Example response:
+
+``` json
+[
+    {
+        "author": {
+            "avatar_url": "http://www.gravatar.com/avatar/edaf55a9e363ea263e3b981d09e0f7f7?s=80&d=identicon",
+            "id": 12,
+            "name": "Libby Rolfson",
+            "state": "active",
+            "username": "elton_wehner",
+            "web_url": "http://localhost:3000/elton_wehner"
+        },
+        "created_at": "2016-11-25T16:53:34.504Z",
+        "file_name": "oconnerrice.rb",
+        "id": 49,
+        "raw_url": "http://localhost:3000/snippets/49/raw",
+        "title": "Ratione cupiditate et laborum temporibus.",
+        "updated_at": "2016-11-25T16:53:34.504Z",
+        "web_url": "http://localhost:3000/snippets/49"
+    },
+    {
+        "author": {
+            "avatar_url": "http://www.gravatar.com/avatar/36583b28626de71061e6e5a77972c3bd?s=80&d=identicon",
+            "id": 16,
+            "name": "Llewellyn Flatley",
+            "state": "active",
+            "username": "adaline",
+            "web_url": "http://localhost:3000/adaline"
+        },
+        "created_at": "2016-11-25T16:53:34.479Z",
+        "file_name": "muellershields.rb",
+        "id": 48,
+        "raw_url": "http://localhost:3000/snippets/48/raw",
+        "title": "Minus similique nesciunt vel fugiat qui ullam sunt.",
+        "updated_at": "2016-11-25T16:53:34.479Z",
+        "web_url": "http://localhost:3000/snippets/48"
+    }
+]
+```
+
diff --git a/lib/api/api.rb b/lib/api/api.rb
index 67109ceeef9..cec2702e44d 100644
--- a/lib/api/api.rb
+++ b/lib/api/api.rb
@@ -64,6 +64,7 @@ module API
     mount ::API::Session
     mount ::API::Settings
     mount ::API::SidekiqMetrics
+    mount ::API::Snippets
     mount ::API::Subscriptions
     mount ::API::SystemHooks
     mount ::API::Tags
diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index d5dfb8d00be..dc6d085925d 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -200,6 +200,19 @@ module API
       end
     end
 
+    class PersonalSnippet < Grape::Entity
+      expose :id, :title, :file_name
+      expose :author, using: Entities::UserBasic
+      expose :updated_at, :created_at
+
+      expose :web_url do |snippet|
+        Gitlab::UrlBuilder.build(snippet)
+      end
+      expose :raw_url do |snippet|
+        Gitlab::UrlBuilder.build(snippet) + "/raw"
+      end
+    end
+
     class ProjectEntity < Grape::Entity
       expose :id, :iid
       expose(:project_id) { |entity| entity.project.id }
diff --git a/lib/api/snippets.rb b/lib/api/snippets.rb
new file mode 100644
index 00000000000..e096e636806
--- /dev/null
+++ b/lib/api/snippets.rb
@@ -0,0 +1,137 @@
+module API
+  # Snippets API
+  class Snippets < Grape::API
+    include PaginationParams
+
+    before { authenticate! }
+
+    resource :snippets do
+      helpers do
+        def snippets_for_current_user
+          SnippetsFinder.new.execute(current_user, filter: :by_user, user: current_user)
+        end
+
+        def public_snippets
+          SnippetsFinder.new.execute(current_user, filter: :public)
+        end
+      end
+
+      desc 'Get a snippets list for authenticated user' do
+        detail 'This feature was introduced in GitLab 8.15.'
+        success Entities::PersonalSnippet
+      end
+      params do
+        use :pagination
+      end
+      get do
+        present paginate(snippets_for_current_user), with: Entities::PersonalSnippet
+      end
+
+      desc 'List all public snippets current_user has access to' do
+        detail 'This feature was introduced in GitLab 8.15.'
+        success Entities::PersonalSnippet
+      end
+      params do
+        use :pagination
+      end
+      get 'public' do
+        present paginate(public_snippets), with: Entities::PersonalSnippet
+      end
+
+      desc 'Get a single snippet' do
+        detail 'This feature was introduced in GitLab 8.15.'
+        success Entities::PersonalSnippet
+      end
+      params do
+        requires :id, type: Integer, desc: 'The ID of a snippet'
+      end
+      get ':id' do
+        snippet = snippets_for_current_user.find(params[:id])
+        present snippet, with: Entities::PersonalSnippet
+      end
+
+      desc 'Create new snippet' do
+        detail 'This feature was introduced in GitLab 8.15.'
+        success Entities::PersonalSnippet
+      end
+      params do
+        requires :title, type: String, desc: 'The title of a snippet'
+        requires :file_name, type: String, desc: 'The name of a snippet file'
+        requires :content, type: String, desc: 'The content of a snippet'
+        optional :visibility_level, type: Integer,
+                                    values: Gitlab::VisibilityLevel.values,
+                                    default: Gitlab::VisibilityLevel::INTERNAL,
+                                    desc: 'The visibility level of the snippet'
+      end
+      post do
+        attrs = declared_params(include_missing: false)
+        snippet = CreateSnippetService.new(nil, current_user, attrs).execute
+
+        if snippet.persisted?
+          present snippet, with: Entities::PersonalSnippet
+        else
+          render_validation_error!(snippet)
+        end
+      end
+
+      desc 'Update an existing snippet' do
+        detail 'This feature was introduced in GitLab 8.15.'
+        success Entities::PersonalSnippet
+      end
+      params do
+        requires :id, type: Integer, desc: 'The ID of a snippet'
+        optional :title, type: String, desc: 'The title of a snippet'
+        optional :file_name, type: String, desc: 'The name of a snippet file'
+        optional :content, type: String, desc: 'The content of a snippet'
+        optional :visibility_level, type: Integer,
+                                    values: Gitlab::VisibilityLevel.values,
+                                    desc: 'The visibility level of the snippet'
+        at_least_one_of :title, :file_name, :content, :visibility_level
+      end
+      put ':id' do
+        snippet = snippets_for_current_user.find_by(id: params.delete(:id))
+        return not_found!('Snippet') unless snippet
+        authorize! :update_personal_snippet, snippet
+
+        attrs = declared_params(include_missing: false)
+
+        UpdateSnippetService.new(nil, current_user, snippet, attrs).execute
+        if snippet.persisted?
+          present snippet, with: Entities::PersonalSnippet
+        else
+          render_validation_error!(snippet)
+        end
+      end
+
+      desc 'Remove snippet' do
+        detail 'This feature was introduced in GitLab 8.15.'
+        success Entities::PersonalSnippet
+      end
+      params do
+        requires :id, type: Integer, desc: 'The ID of a snippet'
+      end
+      delete ':id' do
+        snippet = snippets_for_current_user.find_by(id: params.delete(:id))
+        return not_found!('Snippet') unless snippet
+        authorize! :destroy_personal_snippet, snippet
+        snippet.destroy
+        no_content!
+      end
+
+      desc 'Get a raw snippet' do
+        detail 'This feature was introduced in GitLab 8.15.'
+      end
+      params do
+        requires :id, type: Integer, desc: 'The ID of a snippet'
+      end
+      get ":id/raw" do
+        snippet = snippets_for_current_user.find_by(id: params.delete(:id))
+        return not_found!('Snippet') unless snippet
+
+        env['api.format'] = :txt
+        content_type 'text/plain'
+        present snippet.content
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/url_builder.rb b/lib/gitlab/url_builder.rb
index 99d0c28e749..ccb456bcc94 100644
--- a/lib/gitlab/url_builder.rb
+++ b/lib/gitlab/url_builder.rb
@@ -24,6 +24,8 @@ module Gitlab
         wiki_page_url
       when ProjectSnippet
         project_snippet_url(object)
+      when Snippet
+        personal_snippet_url(object)
       else
         raise NotImplementedError.new("No URL builder defined for #{object.class}")
       end
diff --git a/spec/finders/snippets_finder_spec.rb b/spec/finders/snippets_finder_spec.rb
index 28bdc18e840..4427443208a 100644
--- a/spec/finders/snippets_finder_spec.rb
+++ b/spec/finders/snippets_finder_spec.rb
@@ -9,65 +9,74 @@ describe SnippetsFinder do
   let(:project2) { create(:empty_project, :private, group: group) }
 
   context ':all filter' do
-    before do
-      @snippet1 = create(:personal_snippet, :private)
-      @snippet2 = create(:personal_snippet, :internal)
-      @snippet3 = create(:personal_snippet, :public)
-    end
+    let!(:snippet1) { create(:personal_snippet, :private) }
+    let!(:snippet2) { create(:personal_snippet, :internal) }
+    let!(:snippet3) { create(:personal_snippet, :public) }
 
     it "returns all private and internal snippets" do
       snippets = SnippetsFinder.new.execute(user, filter: :all)
-      expect(snippets).to include(@snippet2, @snippet3)
-      expect(snippets).not_to include(@snippet1)
+      expect(snippets).to include(snippet2, snippet3)
+      expect(snippets).not_to include(snippet1)
     end
 
     it "returns all public snippets" do
       snippets = SnippetsFinder.new.execute(nil, filter: :all)
-      expect(snippets).to include(@snippet3)
-      expect(snippets).not_to include(@snippet1, @snippet2)
+      expect(snippets).to include(snippet3)
+      expect(snippets).not_to include(snippet1, snippet2)
     end
   end
 
-  context ':by_user filter' do
-    before do
-      @snippet1 = create(:personal_snippet, :private,  author: user)
-      @snippet2 = create(:personal_snippet, :internal, author: user)
-      @snippet3 = create(:personal_snippet, :public,   author: user)
+  context ':public filter' do
+    let!(:snippet1) { create(:personal_snippet, :private) }
+    let!(:snippet2) { create(:personal_snippet, :internal) }
+    let!(:snippet3) { create(:personal_snippet, :public) }
+
+    it "returns public public snippets" do
+      snippets = SnippetsFinder.new.execute(nil, filter: :public)
+
+      expect(snippets).to include(snippet3)
+      expect(snippets).not_to include(snippet1, snippet2)
     end
+  end
+
+  context ':by_user filter' do
+    let!(:snippet1) { create(:personal_snippet, :private, author: user) }
+    let!(:snippet2) { create(:personal_snippet, :internal, author: user) }
+    let!(:snippet3) { create(:personal_snippet, :public, author: user) }
 
     it "returns all public and internal snippets" do
       snippets = SnippetsFinder.new.execute(user1, filter: :by_user, user: user)
-      expect(snippets).to include(@snippet2, @snippet3)
-      expect(snippets).not_to include(@snippet1)
+      expect(snippets).to include(snippet2, snippet3)
+      expect(snippets).not_to include(snippet1)
     end
 
     it "returns internal snippets" do
       snippets = SnippetsFinder.new.execute(user, filter: :by_user, user: user, scope: "are_internal")
-      expect(snippets).to include(@snippet2)
-      expect(snippets).not_to include(@snippet1, @snippet3)
+      expect(snippets).to include(snippet2)
+      expect(snippets).not_to include(snippet1, snippet3)
     end
 
     it "returns private snippets" do
       snippets = SnippetsFinder.new.execute(user, filter: :by_user, user: user, scope: "are_private")
-      expect(snippets).to include(@snippet1)
-      expect(snippets).not_to include(@snippet2, @snippet3)
+      expect(snippets).to include(snippet1)
+      expect(snippets).not_to include(snippet2, snippet3)
     end
 
     it "returns public snippets" do
       snippets = SnippetsFinder.new.execute(user, filter: :by_user, user: user, scope: "are_public")
-      expect(snippets).to include(@snippet3)
-      expect(snippets).not_to include(@snippet1, @snippet2)
+      expect(snippets).to include(snippet3)
+      expect(snippets).not_to include(snippet1, snippet2)
     end
 
     it "returns all snippets" do
       snippets = SnippetsFinder.new.execute(user, filter: :by_user, user: user)
-      expect(snippets).to include(@snippet1, @snippet2, @snippet3)
+      expect(snippets).to include(snippet1, snippet2, snippet3)
     end
 
     it "returns only public snippets if unauthenticated user" do
       snippets = SnippetsFinder.new.execute(nil, filter: :by_user, user: user)
-      expect(snippets).to include(@snippet3)
-      expect(snippets).not_to include(@snippet2, @snippet1)
+      expect(snippets).to include(snippet3)
+      expect(snippets).not_to include(snippet2, snippet1)
     end
   end
 
diff --git a/spec/requests/api/snippets_spec.rb b/spec/requests/api/snippets_spec.rb
new file mode 100644
index 00000000000..f6fb6ea5506
--- /dev/null
+++ b/spec/requests/api/snippets_spec.rb
@@ -0,0 +1,157 @@
+require 'rails_helper'
+
+describe API::Snippets, api: true do
+  include ApiHelpers
+  let!(:user) { create(:user) }
+
+  describe 'GET /snippets/' do
+    it 'returns snippets available' do
+      public_snippet = create(:personal_snippet, :public, author: user)
+      private_snippet = create(:personal_snippet, :private, author: user)
+      internal_snippet = create(:personal_snippet, :internal, author: user)
+
+      get api("/snippets/", user)
+
+      expect(response).to have_http_status(200)
+      expect(json_response.map { |snippet| snippet['id']} ).to contain_exactly(
+        public_snippet.id,
+        internal_snippet.id,
+        private_snippet.id)
+      expect(json_response.last).to have_key('web_url')
+      expect(json_response.last).to have_key('raw_url')
+    end
+
+    it 'hides private snippets from regular user' do
+      create(:personal_snippet, :private)
+
+      get api("/snippets/", user)
+      expect(response).to have_http_status(200)
+      expect(json_response.size).to eq(0)
+    end
+  end
+
+  describe 'GET /snippets/public' do
+    let!(:other_user) { create(:user) }
+    let!(:public_snippet) { create(:personal_snippet, :public, author: user) }
+    let!(:private_snippet) { create(:personal_snippet, :private, author: user) }
+    let!(:internal_snippet) { create(:personal_snippet, :internal, author: user) }
+    let!(:public_snippet_other) { create(:personal_snippet, :public, author: other_user) }
+    let!(:private_snippet_other) { create(:personal_snippet, :private, author: other_user) }
+    let!(:internal_snippet_other) { create(:personal_snippet, :internal, author: other_user) }
+
+    it 'returns all snippets with public visibility from all users' do
+      get api("/snippets/public", user)
+
+      expect(response).to have_http_status(200)
+      expect(json_response.map { |snippet| snippet['id']} ).to contain_exactly(
+        public_snippet.id,
+        public_snippet_other.id)
+      expect(json_response.map{ |snippet| snippet['web_url']} ).to include(
+        "http://localhost/snippets/#{public_snippet.id}",
+        "http://localhost/snippets/#{public_snippet_other.id}")
+      expect(json_response.map{ |snippet| snippet['raw_url']} ).to include(
+        "http://localhost/snippets/#{public_snippet.id}/raw",
+        "http://localhost/snippets/#{public_snippet_other.id}/raw")
+    end
+  end
+
+  describe 'GET /snippets/:id/raw' do
+    let(:snippet) { create(:personal_snippet, author: user) }
+
+    it 'returns raw text' do
+      get api("/snippets/#{snippet.id}/raw", user)
+
+      expect(response).to have_http_status(200)
+      expect(response.content_type).to eq 'text/plain'
+      expect(response.body).to eq(snippet.content)
+    end
+
+    it 'returns 404 for invalid snippet id' do
+      delete api("/snippets/1234", user)
+
+      expect(response).to have_http_status(404)
+      expect(json_response['message']).to eq('404 Snippet Not Found')
+    end
+  end
+
+  describe 'POST /snippets/' do
+    let(:params) do
+      {
+        title: 'Test Title',
+        file_name: 'test.rb',
+        content: 'puts "hello world"',
+        visibility_level: Gitlab::VisibilityLevel::PUBLIC
+      }
+    end
+
+    it 'creates a new snippet' do
+      expect do
+        post api("/snippets/", user), params
+      end.to change { PersonalSnippet.count }.by(1)
+
+      expect(response).to have_http_status(201)
+      expect(json_response['title']).to eq(params[:title])
+      expect(json_response['file_name']).to eq(params[:file_name])
+    end
+
+    it 'returns 400 for missing parameters' do
+      params.delete(:title)
+
+      post api("/snippets/", user), params
+
+      expect(response).to have_http_status(400)
+    end
+  end
+
+  describe 'PUT /snippets/:id' do
+    let(:other_user) { create(:user) }
+    let(:public_snippet) { create(:personal_snippet, :public, author: user) }
+    it 'updates snippet' do
+      new_content = 'New content'
+
+      put api("/snippets/#{public_snippet.id}", user), content: new_content
+
+      expect(response).to have_http_status(200)
+      public_snippet.reload
+      expect(public_snippet.content).to eq(new_content)
+    end
+
+    it 'returns 404 for invalid snippet id' do
+      put api("/snippets/1234", user), title: 'foo'
+
+      expect(response).to have_http_status(404)
+      expect(json_response['message']).to eq('404 Snippet Not Found')
+    end
+
+    it "returns 404 for another user's snippet" do
+      put api("/snippets/#{public_snippet.id}", other_user), title: 'fubar'
+
+      expect(response).to have_http_status(404)
+      expect(json_response['message']).to eq('404 Snippet Not Found')
+    end
+
+    it 'returns 400 for missing parameters' do
+      put api("/snippets/1234", user)
+
+      expect(response).to have_http_status(400)
+    end
+  end
+
+  describe 'DELETE /snippets/:id' do
+    let!(:public_snippet) { create(:personal_snippet, :public, author: user) }
+    it 'deletes snippet' do
+      expect do
+        delete api("/snippets/#{public_snippet.id}", user)
+
+        expect(response).to have_http_status(204)
+      end.to change { PersonalSnippet.count }.by(-1)
+    end
+
+    it 'returns 404 for invalid snippet id' do
+      delete api("/snippets/1234", user)
+
+      expect(response).to have_http_status(404)
+      expect(json_response['message']).to eq('404 Snippet Not Found')
+    end
+  end
+end