FEATURE: Allow user to leave a PM.

app/assets/javascripts/discourse/controllers/topic.js.es6

@@ -231,7 +231,11 @@ export default Ember.Controller.extend(SelectedPostsCount, BufferedContent, {
     },
 
     removeAllowedUser(user) {
-      return this.get('model.details').removeAllowedUser(user);
+      return this.get('model.details').removeAllowedUser(user).then(() => {
+        if (this.currentUser.id === user.id) {
+          this.transitionToRoute("userPrivateMessages", user);
+        }
+      });
     },
 
     removeAllowedGroup(group) {

app/assets/javascripts/discourse/lib/transform-post.js.es6

@@ -127,6 +127,7 @@ export default function transformPost(currentUser, site, post, prevPost, nextPos
     postAtts.allowedGroups = details.allowed_groups;
     postAtts.allowedUsers = details.allowed_users;
     postAtts.canRemoveAllowedUsers = details.can_remove_allowed_users;
+    postAtts.canRemoveSelfId = details.can_remove_self_id;
     postAtts.canInvite = details.can_invite_to;
   }
 

app/assets/javascripts/discourse/widgets/post-small-action.js.es6

@@ -48,6 +48,7 @@ const icons = {
   'split_topic': 'sign-out',
   'invited_user': 'plus-circle',
   'invited_group': 'plus-circle',
+  'user_left': 'minus-circle',
   'removed_user': 'minus-circle',
   'removed_group': 'minus-circle',
   'public_topic': 'comment',

app/assets/javascripts/discourse/widgets/private-message-map.js.es6

@@ -36,8 +36,12 @@ createWidget('pm-remove-link', {
   template: hbs`{{d-icon "times"}}`,
 
   click() {
-    bootbox.confirm(I18n.t("private_message_info.remove_allowed_user", {name: this.attrs.username}), (confirmed) => {
+    const messageKey = this.attrs.isCurrentUser ? 'leave_message' : 'remove_allowed_user';
-      if (confirmed) { this.sendWidgetAction('removeAllowedUser', this.attrs); }
+
+    bootbox.confirm(I18n.t(`private_message_info.${messageKey}`, { name: this.attrs.user.username }), confirmed => {
+      if (confirmed) {
+        this.sendWidgetAction('removeAllowedUser', this.attrs.user);
+      }
     });
   }
 });
@@ -49,11 +53,12 @@ createWidget('pm-map-user', {
     const user = attrs.user;
     const avatar = avatarFor('small', { template: user.avatar_template, username: user.username });
     const link = h('a', { attributes: { href: user.get('path') } }, [ avatar, ' ', user.username ]);
-
     const result = [link];
-    if (attrs.canRemoveAllowedUsers) {
+    const isCurrentUser = attrs.canRemoveSelfId === user.get('id');
+
+    if (attrs.canRemoveAllowedUsers || isCurrentUser) {
       result.push(' ');
-      result.push(this.attach('pm-remove-link', user));
+      result.push(this.attach('pm-remove-link', { user, isCurrentUser } ));
     }
 
     return result;
@@ -67,12 +72,23 @@ export default createWidget('private-message-map', {
     const participants = [];
 
     if (attrs.allowedGroups.length) {
-      participants.push(attrs.allowedGroups.map(ag => this.attach('pm-map-user-group', {group: ag, canRemoveAllowedUsers: attrs.canRemoveAllowedUsers})));
+      participants.push(attrs.allowedGroups.map(ag => {
+        this.attach('pm-map-user-group', {
+          group: ag,
+          canRemoveAllowedUsers: attrs.canRemoveAllowedUsers
+        });
+      }));
     }
 
-    if (attrs.allowedUsers.length) {
+    const allowedUsersLength = attrs.allowedUsers.length;
+
+    if (allowedUsersLength) {
       participants.push(attrs.allowedUsers.map(au => {
-        return this.attach('pm-map-user', { user: au, canRemoveAllowedUsers: attrs.canRemoveAllowedUsers });
+        return this.attach('pm-map-user', {
+          user: au,
+          canRemoveAllowedUsers: attrs.canRemoveAllowedUsers,
+          canRemoveSelfId: attrs.canRemoveSelfId
+        });
       }));
     }
 

app/controllers/topics_controller.rb

@@ -439,9 +439,10 @@ class TopicsController < ApplicationController
   def remove_allowed_user
     params.require(:username)
     topic = Topic.find_by(id: params[:topic_id])
-    guardian.ensure_can_remove_allowed_users!(topic)
+    user = User.find_by(username: params[:username])
+    guardian.ensure_can_remove_allowed_users!(topic, user)
 
-    if topic.remove_allowed_user(current_user, params[:username])
+    if topic.remove_allowed_user(current_user, user)
       render json: success_json
     else
       render json: failed_json, status: 422

app/models/topic.rb

@@ -709,14 +709,21 @@ SQL
   end
 
   def remove_allowed_user(removed_by, username)
-    if user = User.find_by(username: username)
+    user = username.is_a?(User) ? username : User.find_by(username: username)
+
+    if user
       topic_user = topic_allowed_users.find_by(user_id: user.id)
+
       if topic_user
         topic_user.destroy
-        # we can not remove ourselves cause then we will end up adding
+
-        # ourselves in add_small_action
+        if user.id == removed_by&.id
-        removed_by = Discourse.system_user if user.id == removed_by&.id
+          removed_by = Discourse.system_user
+          add_small_action(removed_by, "user_left", user.username)
+        else
           add_small_action(removed_by, "removed_user", user.username)
+        end
+
         return true
       end
     end

app/serializers/topic_view_serializer.rb

@@ -114,6 +114,7 @@ class TopicViewSerializer < ApplicationSerializer
     result[:can_delete] = true if scope.can_delete?(object.topic)
     result[:can_recover] = true if scope.can_recover_topic?(object.topic)
     result[:can_remove_allowed_users] = true if scope.can_remove_allowed_users?(object.topic)
+    result[:can_remove_self_id] = scope.user.id if scope.can_remove_allowed_users?(object.topic, scope.user)
     result[:can_invite_to] = true if scope.can_invite_to?(object.topic)
     result[:can_invite_via_email] = true if scope.can_invite_via_email?(object.topic)
     result[:can_create_post] = true if scope.can_create?(Post, object.topic)

config/locales/client.en.yml

@@ -143,6 +143,7 @@ en:
       split_topic: "split this topic %{when}"
       invited_user: "invited %{who} %{when}"
       invited_group: "invited %{who} %{when}"
+      user_left: "%{who} left this message %{when}"
       removed_user: "removed %{who} %{when}"
       removed_group: "removed %{who} %{when}"
       autoclosed:
@@ -1030,6 +1031,7 @@ en:
     private_message_info:
       title: "Message"
       invite: "Invite Others..."
+      leave_message: "Do you really want to leave this message?"
       remove_allowed_user: "Do you really want to remove {{name}} from this message?"
       remove_allowed_group: "Do you really want to remove {{name}} from this message?"
 

lib/guardian/topic_guardian.rb

@@ -1,8 +1,13 @@
 #mixin for all guardian methods dealing with topic permisions
 module TopicGuardian
 
-  def can_remove_allowed_users?(topic)
+  def can_remove_allowed_users?(topic, target_user = nil)
-    is_staff?
+    is_staff? ||
+    (
+      topic.allowed_users.count > 1 &&
+      topic.user != target_user &&
+      !!(target_user && user == target_user)
+    )
   end
 
   # Creating Methods

spec/components/guardian_spec.rb

@@ -2613,4 +2613,60 @@ describe Guardian do
       end
     end
   end
+
+  describe '#can_remove_allowed_users?' do
+    context 'staff users' do
+      it 'should be true' do
+        expect(Guardian.new(moderator).can_remove_allowed_users?(topic))
+          .to eq(true)
+      end
+    end
+
+    context 'normal user' do
+      let(:topic) { Fabricate(:topic, user: Fabricate(:user)) }
+      let(:another_user) { Fabricate(:user) }
+
+      before do
+        topic.allowed_users << user
+        topic.allowed_users << another_user
+      end
+
+      it 'should be false' do
+        expect(Guardian.new(user).can_remove_allowed_users?(topic))
+          .to eq(false)
+      end
+
+      describe 'target_user is the user' do
+        describe 'when user is in a pm with another user' do
+          it 'should return true' do
+            expect(Guardian.new(user).can_remove_allowed_users?(topic, user))
+              .to eq(true)
+          end
+        end
+
+        describe 'when user is the creator of the topic' do
+          it 'should return false' do
+            expect(Guardian.new(topic.user).can_remove_allowed_users?(topic, topic.user))
+              .to eq(false)
+          end
+        end
+
+        describe 'when user is the only user in the topic' do
+          it 'should return false' do
+            topic.remove_allowed_user(Discourse.system_user, another_user.username)
+
+            expect(Guardian.new(user).can_remove_allowed_users?(topic, user))
+              .to eq(false)
+          end
+        end
+      end
+
+      describe 'target_user is not the user' do
+        it 'should return false' do
+          expect(Guardian.new(user).can_remove_allowed_users?(topic, moderator))
+            .to eq(false)
+        end
+      end
+    end
+  end
 end

spec/models/topic_spec.rb

@@ -6,6 +6,7 @@ require_dependency 'post_destroyer'
 describe Topic do
   let(:now) { Time.zone.local(2013, 11, 20, 8, 0) }
   let(:user) { Fabricate(:user) }
+  let(:topic) { Fabricate(:topic) }
 
   context 'validations' do
     let(:topic) { Fabricate.build(:topic) }
@@ -2040,4 +2041,23 @@ describe Topic do
       end
     end
   end
+
+  describe '#remove_allowed_user' do
+    let(:another_user) { Fabricate(:user) }
+
+    describe 'removing oneself' do
+      it 'should remove onself' do
+        topic.allowed_users << another_user
+
+        expect(topic.remove_allowed_user(another_user, another_user)).to eq(true)
+        expect(topic.allowed_users.include?(another_user)).to eq(false)
+
+        post = Post.last
+
+        expect(post.user).to eq(Discourse.system_user)
+        expect(post.post_type).to eq(Post.types[:small_action])
+        expect(post.action_code).to eq('user_left')
+      end
+    end
+  end
 end