Improve error reporting on users API

* users (#6878, #3526, #4209): Validation error messages are now exposed through 400 responses, 409 response are sent in case of duplicate email or username
* MRs (#5335): 409 responses are sent in case of duplicate merge request (source/target branches), 422 responses are sent when submiting MR fo/from unrelated forks
* issues
* labels
* projects

1 files changed, 37 insertions, 21 deletions

diff --git a/lib/api/users.rb b/lib/api/users.rb
index 69553f16397..d07815a8a97 100644
--- a/lib/api/users.rb
+++ b/lib/api/users.rb
@@ -42,7 +42,8 @@ module API
       # Parameters:
       #   email (required)                  - Email
       #   password (required)               - Password
-      #   name                              - Name
+      #   name (required)                   - Name
+      #   username (required)               - Name
       #   skype                             - Skype ID
       #   linkedin                          - Linkedin
       #   twitter                           - Twitter account
@@ -65,7 +66,15 @@ module API
         if user.save
           present user, with: Entities::UserFull
         else
-          not_found!
+          conflict!('Email has already been taken') if User.
+              where(email: user.email).
+              count > 0
+
+          conflict!('Username has already been taken') if User.
+              where(username: user.username).
+              count > 0
+
+          render_validation_error!(user)
         end
       end
 
@@ -92,14 +101,23 @@ module API
 
         attrs = attributes_for_keys [:email, :name, :password, :skype, :linkedin, :twitter, :website_url, :projects_limit, :username, :extern_uid, :provider, :bio, :can_create_group, :admin]
         user = User.find(params[:id])
-        not_found!("User not found") unless user
+        not_found!('User') unless user
 
         admin = attrs.delete(:admin)
         user.admin = admin unless admin.nil?
+
+        conflict!('Email has already been taken') if attrs[:email] &&
+            User.where(email: attrs[:email]).
+                where.not(id: user.id).count > 0
+
+        conflict!('Username has already been taken') if attrs[:username] &&
+            User.where(username: attrs[:username]).
+                where.not(id: user.id).count > 0
+
         if user.update_attributes(attrs)
           present user, with: Entities::UserFull
         else
-          not_found!
+          render_validation_error!(user)
         end
       end
 
@@ -113,13 +131,15 @@ module API
       # POST /users/:id/keys
       post ":id/keys" do
         authenticated_as_admin!
+        required_attributes! [:title, :key]
+
         user = User.find(params[:id])
         attrs = attributes_for_keys [:title, :key]
         key = user.keys.new attrs
         if key.save
           present key, with: Entities::SSHKey
         else
-          not_found!
+          render_validation_error!(key)
         end
       end
 
@@ -132,11 +152,9 @@ module API
       get ':uid/keys' do
         authenticated_as_admin!
         user = User.find_by(id: params[:uid])
-        if user
-          present user.keys, with: Entities::SSHKey
-        else
-          not_found!
-        end
+        not_found!('User') unless user
+
+        present user.keys, with: Entities::SSHKey
       end
 
       # Delete existing ssh key of a specified user. Only available to admin
@@ -150,15 +168,13 @@ module API
       delete ':uid/keys/:id' do
         authenticated_as_admin!
         user = User.find_by(id: params[:uid])
-        if user
-          begin
-            key = user.keys.find params[:id]
-            key.destroy
-          rescue ActiveRecord::RecordNotFound
-            not_found!
-          end
-        else
-          not_found!
+        not_found!('User') unless user
+
+        begin
+          key = user.keys.find params[:id]
+          key.destroy
+        rescue ActiveRecord::RecordNotFound
+          not_found!('Key')
         end
       end
 
@@ -173,7 +189,7 @@ module API
         if user
           user.destroy
         else
-          not_found!
+          not_found!('User')
         end
       end
     end
@@ -219,7 +235,7 @@ module API
         if key.save
           present key, with: Entities::SSHKey
         else
-          not_found!
+          render_validation_error!(key)
         end
       end