Merge pull request #167 from dblock/once-and-every

Fix timers to run independently, add once_and_every.

Author: dblock

CHANGELOG.md

@@ -5,6 +5,7 @@
 * [#163](https://github.com/slack-ruby/slack-ruby-bot-server/pull/163): Updated releasing documentation - [@crazyoptimist](https://github.com/crazyoptimist).
 * [#164](https://github.com/slack-ruby/slack-ruby-bot-server/pull/164): Added support for Rails 6.1 and 7.0 - [@maths22](https://github.com/maths22).
 * [#168](https://github.com/slack-ruby/slack-ruby-bot-server/pull/168): Added support for Ruby 3.2.1 - [@dblock](https://github.com/dblock).
+* [#167](https://github.com/slack-ruby/slack-ruby-bot-server/pull/167): Added `once_and_every` timer - [@dblock](https://github.com/dblock).
 * Your contribution here.
 
 #### 2.0.1 (2023/02/20)

README.md

@@ -238,9 +238,7 @@ end
 
 ##### Service Timers
 
-You can introduce custom behavior into the service lifecycle on a timer. For example, check whether a team's trial has expired, or periodically cleanup data.
-
-Note that unlike callbacks, timers are global for the entire service.
+You can introduce custom behavior into the service lifecycle on a timer. For example, check whether a team's trial has expired, or periodically clean-up data. Timers can run once on start (`once_and_every`) and start running after a certain period (`every`).
 
 ```ruby
 instance = SlackRubyBotServer::Service.instance
@@ -254,6 +252,10 @@ instance.every :hour do
   end
 end
 
+instance.once_and_every :minute do
+  # called once on start, then every minute
+end
+
 instance.every :minute do
   # called every minute
 end
@@ -267,6 +269,8 @@ instance.every 30 do
 end
 ```
 
+Note that, unlike callbacks, timers are global for the entire service. Timers are independent, and a failing timer will not terminate other timers.
+
 ##### Extensions
 
 A number of extensions use service manager callbacks and service timers to implement useful functionality.

lib/slack-ruby-bot-server/service.rb

@@ -24,19 +24,15 @@ def on(*types, &block)
       end
     end
 
-    def every(*intervals, &block)
+    def once_and_every(*intervals, &block)
       Array(intervals).each do |interval|
-        case interval
-        when :minute
-          interval = 60
-        when :hour
-          interval = 60 * 60
-        when :day
-          interval = 60 * 60 * 24
-        end
-        raise "Invalid interval \"#{interval}\"." unless interval.is_a?(Integer) && interval > 0
+        @intervals[_validate_interval(interval)] << [block, { run_on_start: true }]
+      end
+    end
 
-        @intervals[interval] << block
+    def every(*intervals, &block)
+      Array(intervals).each do |interval|
+        @intervals[_validate_interval(interval)] << [block, {}]
       end
     end
 
@@ -83,9 +79,12 @@ def start_from_database!
     end
 
     def start_intervals!
-      @intervals.each_pair do |period, calls|
-        _every period do
-          calls.each(&:call)
+      @intervals.each_pair do |period, calls_with_options|
+        calls_with_options.each do |call_with_options|
+          call, options = *call_with_options
+          _every period, options do
+            call.call
+          end
         end
       end
     end
@@ -105,10 +104,28 @@ def self.reset!
 
     private
 
-    def _every(tt, &_block)
+    def _validate_interval(interval)
+      case interval
+      when :minute
+        interval = 60
+      when :hour
+        interval = 60 * 60
+      when :day
+        interval = 60 * 60 * 24
+      end
+      raise "Invalid interval \"#{interval}\"." unless interval.is_a?(Integer) && interval > 0
+
+      interval
+    end
+
+    def _every(tt, options = {}, &_block)
       ::Async::Reactor.run do |task|
         loop do
           begin
+            if options[:run_on_start]
+              options = {}
+              yield
+            end
             task.sleep tt
             yield
           rescue StandardError => e

spec/slack-ruby-bot-server/service_spec.rb

@@ -103,6 +103,60 @@
         expect(@events.sort.uniq).to eq %w[1-2s 1s]
       end
     end
+    context 'with a failing timer' do
+      before do
+        @events = []
+        instance.every 1 do
+          @events << 'fail'
+          raise 'error'
+        end
+        instance.every 1 do
+          @events << '1'
+        end
+      end
+      it 'does not abort all timers on failure of the first one' do
+        Async::Reactor.run do |task|
+          instance.start_intervals!
+          task.sleep 3
+          task.stop
+        end
+        expect(@events.sort.uniq).to eq %w[1 fail]
+      end
+    end
+    context 'once_and_every' do
+      context '5 seconds' do
+        before do
+          @events = []
+          instance.once_and_every 5 do
+            @events << '1'
+          end
+        end
+        it 'runs the timer once within 3 seconds' do
+          Async::Reactor.run do |task|
+            instance.start_intervals!
+            task.sleep 3
+            task.stop
+          end
+          expect(@events).to eq %w[1]
+        end
+      end
+      context '2 seconds' do
+        before do
+          @events = []
+          instance.once_and_every 2 do
+            @events << '1'
+          end
+        end
+        it 'runs the timer exactly twice within 3 seconds' do
+          Async::Reactor.run do |task|
+            instance.start_intervals!
+            task.sleep 3
+            task.stop
+          end
+          expect(@events).to eq %w[1 1]
+        end
+      end
+    end
   end
   context 'overriding service_class' do
     let(:service_class) do