Add a reference to the User who registered the time spent.

app/models/concerns/time_trackable.rb

@@ -14,11 +14,13 @@ module TimeTrackable
     alias_method :time_spent?, :time_spent
   end
 
-  def spend_time=(seconds)
-    return if invalid_time_spent?(seconds)
+  def spend_time=(args)
+    return unless valid_spend_time_args?(args)
 
+    seconds = args[:seconds]
     new_time_spent = seconds.zero? ? -(total_time_spent) : seconds
-    timelogs.new(time_spent: new_time_spent)
+
+    timelogs.new(user: args[:user], time_spent: new_time_spent)
 
     @time_spent = seconds
   end
@@ -29,11 +31,13 @@ module TimeTrackable
 
   private
 
-  def invalid_time_spent?(seconds)
-    return true unless seconds
+  def valid_spend_time_args?(args)
+    return false unless [:seconds, :user].all? { |k| args.key?(k) }
+
     # time to subtract exceeds the total time spent
-    return true if seconds < 0 && (seconds.abs > total_time_spent)
+    seconds = args[:seconds]
+    return false if seconds < 0 && (seconds.abs > total_time_spent)
 
-    false
+    true
   end
 end

app/models/timelog.rb

@@ -2,4 +2,5 @@ class Timelog < ActiveRecord::Base
   validates :time_spent, presence: true
 
   belongs_to :trackable, polymorphic: true
+  belongs_to :user
 end

app/services/slash_commands/interpret_service.rb

@@ -271,7 +271,10 @@ module SlashCommands
       time_spent = ChronicDuration.parse(raw_duration, default_unit: 'hours') rescue nil
 
       if time_spent
-        @updates[:spend_time] = reduce_time ? (time_spent * -1) : time_spent
+        @updates[:spend_time] = {
+          seconds: reduce_time ? (time_spent * -1) : time_spent,
+          user: current_user
+        }
       end
     end
 
@@ -290,7 +293,7 @@ module SlashCommands
         current_user.can?(:"admin_#{issuable.to_ability_name}", project)
     end
     command :remove_time_spent do
-      @updates[:spend_time] = 0
+      @updates[:spend_time] = { seconds: 0, user: current_user }
     end
 
     def find_label_ids(labels_param)

db/migrate/20161030020610_create_timelogs.rb

@@ -7,10 +7,12 @@ class CreateTimelogs < ActiveRecord::Migration
     create_table :timelogs do |t|
       t.integer :time_spent, null: false
       t.references :trackable, polymorphic: true
+      t.references :user
 
       t.timestamps null: false
     end
 
     add_index :timelogs, [:trackable_type, :trackable_id]
+    add_index :timelogs, :user_id
   end
 end

db/schema.rb

@@ -1257,11 +1257,13 @@ ActiveRecord::Schema.define(version: 20161106185620) do
     t.integer "time_spent", null: false
     t.integer "trackable_id"
     t.string "trackable_type"
+    t.integer "user_id"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
   end
 
   add_index "timelogs", ["trackable_type", "trackable_id"], name: "index_timelogs_on_trackable_type_and_trackable_id", using: :btree
+  add_index "timelogs", ["user_id"], name: "index_timelogs_on_user_id", using: :btree
 
   create_table "todos", force: :cascade do |t|
     t.integer "user_id", null: false

spec/models/concerns/issuable_spec.rb

@@ -386,11 +386,12 @@ describe Issue, "Issuable" do
   end
 
   describe '#spend_time' do
+    let(:user) { create(:user) }
     let(:issue) { create(:issue) }
 
     context 'adding time' do
       it 'should update the total time spent' do
-        issue.update_attributes!(spend_time: 1800)
+        issue.update_attributes!(spend_time: { seconds: 1800, user: user })
 
         expect(issue.total_time_spent).to eq(1800)
       end
@@ -398,18 +399,18 @@ describe Issue, "Issuable" do
 
     context 'substracting time' do
       before do
-        issue.update_attributes!(spend_time: 1800)
+        issue.update_attributes!(spend_time: { seconds: 1800, user: user })
       end
 
       it 'should update the total time spent' do
-        issue.update_attributes!(spend_time: -900)
+        issue.update_attributes!(spend_time: { seconds: -900, user: user })
 
         expect(issue.total_time_spent).to eq(900)
       end
 
       context 'when time to substract exceeds the total time spent' do
         it 'should not alter the total time spent' do
-          issue.update_attributes!(spend_time: -3600)
+          issue.update_attributes!(spend_time: { seconds: -3600, user: user })
 
           expect(issue.total_time_spent).to eq(1800)
         end

spec/services/slash_commands/interpret_service_spec.rb

@@ -219,18 +219,18 @@ describe SlashCommands::InterpretService, services: true do
     end
 
     shared_examples 'spend command' do
-      it 'populates spend_time: "3600" if content contains /spend 1h' do
+      it 'populates spend_time: { seconds: 3600, user: user } if content contains /spend 1h' do
         _, updates = service.execute(content, issuable)
 
-        expect(updates).to eq(spend_time: 3600)
+        expect(updates).to eq(spend_time: { seconds: 3600, user: developer })
       end
     end
 
     shared_examples 'spend command with negative time' do
-      it 'populates spend_time: "-1800" if content contains /spend -30m' do
+      it 'populates spend_time: { seconds: -1800, user: user } if content contains /spend -30m' do
         _, updates = service.execute(content, issuable)
 
-        expect(updates).to eq(spend_time: -1800)
+        expect(updates).to eq(spend_time: { seconds: -1800, user: developer })
       end
     end
 
@@ -246,7 +246,7 @@ describe SlashCommands::InterpretService, services: true do
       it 'populates spend_time: "0" if content contains /remove_time_spent' do
         _, updates = service.execute(content, issuable)
 
-        expect(updates).to eq(spend_time: 0)
+        expect(updates).to eq(spend_time: { seconds: 0, user: developer })
       end
     end