Expose readme url in Project API

app/models/project.rb

@@ -894,6 +894,13 @@ class Project < ActiveRecord::Base
     Gitlab::Routing.url_helpers.project_url(self)
   end
 
+  def readme_url
+    readme = repository.readme
+    if readme
+      Gitlab::Routing.url_helpers.project_blob_url(self, File.join(default_branch, readme.path))
+    end
+  end
+
   def new_issuable_address(author, address_type)
     return unless Gitlab::IncomingEmail.supports_issue_creation? && author
 

changelogs/unreleased/45827-expose_readme_url_in_project_api.yml

+---
+title: Expose readme url in Project API
+merge_request: 18960
+author: Imre Farkas
+type: changed

doc/api/projects.md

@@ -66,6 +66,7 @@ GET /projects
     "ssh_url_to_repo": "git@example.com:diaspora/diaspora-client.git",
     "http_url_to_repo": "http://example.com/diaspora/diaspora-client.git",
     "web_url": "http://example.com/diaspora/diaspora-client",
+    "readme_url": "http://example.com/diaspora/diaspora-client/blob/master/README.md",
     "tag_list": [
       "example",
       "disapora client"
@@ -135,6 +136,7 @@ GET /projects
     "ssh_url_to_repo": "git@example.com:brightbox/puppet.git",
     "http_url_to_repo": "http://example.com/brightbox/puppet.git",
     "web_url": "http://example.com/brightbox/puppet",
+    "readme_url": "http://example.com/brightbox/puppet/blob/master/README.md",
     "tag_list": [
       "example",
       "puppet"
@@ -252,6 +254,7 @@ GET /users/:user_id/projects
     "ssh_url_to_repo": "git@example.com:diaspora/diaspora-client.git",
     "http_url_to_repo": "http://example.com/diaspora/diaspora-client.git",
     "web_url": "http://example.com/diaspora/diaspora-client",
+    "readme_url": "http://example.com/diaspora/diaspora-client/blob/master/README.md",
     "tag_list": [
       "example",
       "disapora client"
@@ -321,6 +324,7 @@ GET /users/:user_id/projects
     "ssh_url_to_repo": "git@example.com:brightbox/puppet.git",
     "http_url_to_repo": "http://example.com/brightbox/puppet.git",
     "web_url": "http://example.com/brightbox/puppet",
+    "readme_url": "http://example.com/brightbox/puppet/blob/master/README.md",
     "tag_list": [
       "example",
       "puppet"
@@ -420,6 +424,7 @@ GET /projects/:id
   "ssh_url_to_repo": "git@example.com:diaspora/diaspora-project-site.git",
   "http_url_to_repo": "http://example.com/diaspora/diaspora-project-site.git",
   "web_url": "http://example.com/diaspora/diaspora-project-site",
+  "readme_url": "http://example.com/diaspora/diaspora-project-site/blob/master/README.md",
   "tag_list": [
     "example",
     "disapora project"
@@ -710,6 +715,7 @@ Example responses:
     "ssh_url_to_repo": "git@example.com:diaspora/diaspora-project-site.git",
     "http_url_to_repo": "http://example.com/diaspora/diaspora-project-site.git",
     "web_url": "http://example.com/diaspora/diaspora-project-site",
+    "readme_url": "http://example.com/diaspora/diaspora-project-site/blob/master/README.md",
     "tag_list": [
       "example",
       "disapora project"
@@ -788,6 +794,7 @@ Example response:
   "ssh_url_to_repo": "git@example.com:diaspora/diaspora-project-site.git",
   "http_url_to_repo": "http://example.com/diaspora/diaspora-project-site.git",
   "web_url": "http://example.com/diaspora/diaspora-project-site",
+  "readme_url": "http://example.com/diaspora/diaspora-project-site/blob/master/README.md",
   "tag_list": [
     "example",
     "disapora project"
@@ -865,6 +872,7 @@ Example response:
   "ssh_url_to_repo": "git@example.com:diaspora/diaspora-project-site.git",
   "http_url_to_repo": "http://example.com/diaspora/diaspora-project-site.git",
   "web_url": "http://example.com/diaspora/diaspora-project-site",
+  "readme_url": "http://example.com/diaspora/diaspora-project-site/blob/master/README.md",
   "tag_list": [
     "example",
     "disapora project"
@@ -966,6 +974,7 @@ Example response:
   "ssh_url_to_repo": "git@example.com:diaspora/diaspora-project-site.git",
   "http_url_to_repo": "http://example.com/diaspora/diaspora-project-site.git",
   "web_url": "http://example.com/diaspora/diaspora-project-site",
+  "readme_url": "http://example.com/diaspora/diaspora-project-site/blob/master/README.md",
   "tag_list": [
     "example",
     "disapora project"
@@ -1061,6 +1070,7 @@ Example response:
   "ssh_url_to_repo": "git@example.com:diaspora/diaspora-project-site.git",
   "http_url_to_repo": "http://example.com/diaspora/diaspora-project-site.git",
   "web_url": "http://example.com/diaspora/diaspora-project-site",
+  "readme_url": "http://example.com/diaspora/diaspora-project-site/blob/master/README.md",
   "tag_list": [
     "example",
     "disapora project"
@@ -1421,4 +1431,3 @@ GET /projects/:id/snapshot
 | --------- | ---- | -------- | ----------- |
 | `id`      | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) |
 | `wiki`    | boolean | no | Whether to download the wiki, rather than project, repository |
-

lib/api/entities.rb

@@ -125,7 +125,7 @@ module API
         # (fixed in https://github.com/rails/rails/pull/25976).
         project.tags.map(&:name).sort
       end
-      expose :ssh_url_to_repo, :http_url_to_repo, :web_url
+      expose :ssh_url_to_repo, :http_url_to_repo, :web_url, :readme_url
       expose :avatar_url do |project, options|
         project.avatar_url(only_path: false)
       end

spec/fixtures/api/schemas/public_api/v4/projects.json

@@ -20,6 +20,7 @@
       "ssh_url_to_repo": { "type": "string" },
       "http_url_to_repo": { "type": "string" },
       "web_url": { "type": "string" },
+      "readme_url": { "type": ["string", "null"] },
       "avatar_url": { "type": ["string", "null"] },
       "star_count": { "type": "integer" },
       "forks_count": { "type": "integer" },

spec/models/project_spec.rb

@@ -469,6 +469,34 @@ describe Project do
     end
   end
 
+  describe "#readme_url" do
+    let(:project) { create(:project, :repository, path: "somewhere") }
+
+    context 'with a non-existing repository' do
+      it 'returns nil' do
+        allow(project.repository).to receive(:tree).with(:head).and_return(nil)
+
+        expect(project.readme_url).to be_nil
+      end
+    end
+
+    context 'with an existing repository' do
+      context 'when no README exists' do
+        it 'returns nil' do
+          allow_any_instance_of(Tree).to receive(:readme).and_return(nil)
+
+          expect(project.readme_url).to be_nil
+        end
+      end
+
+      context 'when a README exists' do
+        it 'returns the README' do
+          expect(project.readme_url).to eql("#{Gitlab.config.gitlab.url}/#{project.namespace.full_path}/somewhere/blob/master/README.md")
+        end
+      end
+    end
+  end
+
   describe "#new_issuable_address" do
     let(:project) { create(:project, path: "somewhere") }
     let(:user) { create(:user) }

spec/requests/api/environments_spec.rb

@@ -15,7 +15,7 @@ describe API::Environments do
       it 'returns project environments' do
         project_data_keys = %w(
           id description default_branch tag_list
-          ssh_url_to_repo http_url_to_repo web_url
+          ssh_url_to_repo http_url_to_repo web_url readme_url
           name name_with_namespace
           path path_with_namespace
           star_count forks_count

spec/requests/api/projects_spec.rb

@@ -18,7 +18,7 @@ describe API::Projects do
   let(:user2) { create(:user) }
   let(:user3) { create(:user) }
   let(:admin) { create(:admin) }
-  let(:project) { create(:project, namespace: user.namespace) }
+  let(:project) { create(:project, :repository, namespace: user.namespace) }
   let(:project2) { create(:project, namespace: user.namespace) }
   let(:snippet) { create(:project_snippet, :public, author: user, project: project, title: 'example') }
   let(:project_member) { create(:project_member, :developer, user: user3, project: project) }
@@ -220,7 +220,7 @@ describe API::Projects do
         it 'returns a simplified version of all the projects' do
           expected_keys = %w(
             id description default_branch tag_list
-            ssh_url_to_repo http_url_to_repo web_url
+            ssh_url_to_repo http_url_to_repo web_url readme_url
             name name_with_namespace
             path path_with_namespace
             star_count forks_count
@@ -854,6 +854,7 @@ describe API::Projects do
         expect(json_response['only_allow_merge_if_pipeline_succeeds']).to eq(project.only_allow_merge_if_pipeline_succeeds)
         expect(json_response['only_allow_merge_if_all_discussions_are_resolved']).to eq(project.only_allow_merge_if_all_discussions_are_resolved)
         expect(json_response['merge_method']).to eq(project.merge_method.to_s)
+        expect(json_response['readme_url']).to eq(project.readme_url)
       end
 
       it 'returns a project by path name' do

spec/requests/api/v3/projects_spec.rb

@@ -82,7 +82,7 @@ describe API::V3::Projects do
         it 'returns a simplified version of all the projects' do
           expected_keys = %w(
             id description default_branch tag_list
-            ssh_url_to_repo http_url_to_repo web_url
+            ssh_url_to_repo http_url_to_repo web_url readme_url
             name name_with_namespace
             path path_with_namespace
             star_count forks_count