Add time-based feature enablements to expressions

examples/expressions.rb

@@ -31,13 +31,9 @@ class Org < Struct.new(:id, :flipper_properties)
   include Flipper::Identifier
 end
 
-NOW = Time.now.to_i
-DAY = 60 * 60 * 24
-
 org = Org.new(1, {
   "type" => "Org",
   "id" => 1,
-  "now" => NOW,
 })
 
 user = User.new(1, {
@@ -46,15 +42,13 @@ class Org < Struct.new(:id, :flipper_properties)
   "plan" => "basic",
   "age" => 39,
   "team_user" => true,
-  "now" => NOW,
 })
 
 admin_user = User.new(2, {
   "type" => "User",
   "id" => 2,
   "admin" => true,
   "team_user" => true,
-  "now" => NOW,
 })
 
 other_user = User.new(3, {
@@ -63,7 +57,6 @@ class Org < Struct.new(:id, :flipper_properties)
   "plan" => "plus",
   "age" => 18,
   "org_admin" => true,
-  "now" => NOW - DAY,
 })
 
 age_expression = Flipper.property(:age).gte(21)
@@ -205,9 +198,40 @@ class Org < Struct.new(:id, :flipper_properties)
 assert Flipper.enabled?(:something, admin_user)
 refute Flipper.enabled?(:something, other_user)
 
-puts "\n\nEnabling based on time"
-scheduled_time_expression = Flipper.property(:now).gte(NOW)
-Flipper.enable :something, scheduled_time_expression
+puts "\n\nEnabling based on time (epoch)"
+scheduled_epoch = Flipper.now.gte(Flipper.time(Time.now.to_i - 86_400))
+Flipper.enable :something, scheduled_epoch
 assert Flipper.enabled?(:something, user)
 assert Flipper.enabled?(:something, admin_user)
-refute Flipper.enabled?(:something, other_user)
+assert Flipper.enabled?(:something, other_user)
+reset
+
+puts "\n\nEnabling based on time (datetime)"
+past_time = (Time.now.utc - 86_400).iso8601
+scheduled_datetime = Flipper.now.gte(Flipper.time(past_time))
+Flipper.enable :something, scheduled_datetime
+assert Flipper.enabled?(:something, user)
+assert Flipper.enabled?(:something, admin_user)
+assert Flipper.enabled?(:something, other_user)
+reset
+
+puts "\n\nDisabling after a time (expiring feature)"
+future_time = (Time.now.utc + 86_400).iso8601
+expiring_expression = Flipper.now.lt(Flipper.time(future_time))
+Flipper.enable :something, expiring_expression
+assert Flipper.enabled?(:something, user)
+assert Flipper.enabled?(:something, admin_user)
+assert Flipper.enabled?(:something, other_user)
+reset
+
+puts "\n\nEnabling within a time window"
+start_time = (Time.now.utc - 86_400).iso8601
+end_time = (Time.now.utc + 86_400).iso8601
+time_window = Flipper.all(
+  Flipper.now.gte(Flipper.time(start_time)),
+  Flipper.now.lt(Flipper.time(end_time))
+)
+Flipper.enable :something, time_window
+assert Flipper.enabled?(:something, user)
+assert Flipper.enabled?(:something, admin_user)
+assert Flipper.enabled?(:something, other_user)

lib/flipper.rb

@@ -100,6 +100,18 @@ def random(max)
     Expression.build({ Random: max })
   end
 
+  def now
+    Expression.build({ Now: [] })
+  end
+
+  def time(value)
+    Expression.build({ Time: value })
+  end
+
+  def duration(scalar, unit = 'second')
+    Expression.build({ Duration: [scalar, unit] })
+  end
+
   def feature_enabled(name)
     Expression.build({ FeatureEnabled: name })
   end

lib/flipper/expressions/time.rb

@@ -1,8 +1,15 @@
+require "time"
+
 module Flipper
   module Expressions
     class Time
       def self.call(value)
-        ::Time.parse(value)
+        case value
+        when Numeric
+          ::Time.at(value).utc
+        else
+          ::Time.parse(value)
+        end
       end
     end
   end

spec/flipper/expressions/time_spec.rb

@@ -9,5 +9,13 @@
     it "returns time for #iso8601 format" do
       expect(described_class.call(time.iso8601)).to eq(time)
     end
+
+    it "returns time for epoch integer" do
+      expect(described_class.call(time.to_i)).to eq(Time.at(time.to_i).utc)
+    end
+
+    it "returns time for epoch float" do
+      expect(described_class.call(time.to_f)).to be_within(0.001).of(time)
+    end
   end
 end

spec/flipper/gates/expression_spec.rb

@@ -99,6 +99,64 @@ def context(expression, properties: {})
         expect(subject.open?(context)).to be(false)
       end
     end
+
+    context 'for time-based expressions' do
+      it 'enables when now is past a scheduled epoch' do
+        past_epoch = Time.now.to_i - 86_400
+        expression = Flipper.now.gte(Flipper.time(past_epoch))
+        expect(subject.open?(context(expression.value))).to be(true)
+      end
+
+      it 'does not enable when now is before a future epoch' do
+        future_epoch = Time.now.to_i + 86_400
+        expression = Flipper.now.gte(Flipper.time(future_epoch))
+        expect(subject.open?(context(expression.value))).to be(false)
+      end
+
+      it 'enables when now is past a scheduled datetime' do
+        past_time = (Time.now.utc - 86_400).iso8601
+        expression = Flipper.now.gte(Flipper.time(past_time))
+        expect(subject.open?(context(expression.value))).to be(true)
+      end
+
+      it 'does not enable when now is before a future datetime' do
+        future_time = (Time.now.utc + 86_400).iso8601
+        expression = Flipper.now.gte(Flipper.time(future_time))
+        expect(subject.open?(context(expression.value))).to be(false)
+      end
+
+      it 'enables expiring features with lt' do
+        future_time = (Time.now.utc + 86_400).iso8601
+        expression = Flipper.now.lt(Flipper.time(future_time))
+        expect(subject.open?(context(expression.value))).to be(true)
+      end
+
+      it 'disables expired features with lt' do
+        past_time = (Time.now.utc - 86_400).iso8601
+        expression = Flipper.now.lt(Flipper.time(past_time))
+        expect(subject.open?(context(expression.value))).to be(false)
+      end
+
+      it 'enables within a time window using all' do
+        start_time = (Time.now.utc - 86_400).iso8601
+        end_time = (Time.now.utc + 86_400).iso8601
+        expression = Flipper.all(
+          Flipper.now.gte(Flipper.time(start_time)),
+          Flipper.now.lt(Flipper.time(end_time))
+        )
+        expect(subject.open?(context(expression.value))).to be(true)
+      end
+
+      it 'does not enable outside a time window' do
+        start_time = (Time.now.utc + 86_400).iso8601
+        end_time = (Time.now.utc + 172_800).iso8601
+        expression = Flipper.all(
+          Flipper.now.gte(Flipper.time(start_time)),
+          Flipper.now.lt(Flipper.time(end_time))
+        )
+        expect(subject.open?(context(expression.value))).to be(false)
+      end
+    end
   end
 
   describe '#protects?' do