Add while enumerator

lib/job-iteration/enumerator_builder.rb

@@ -181,6 +181,32 @@ def build_nested_enumerator(enums, cursor:)
       NestedEnumerator.new(enums, cursor: cursor).each
     end
 
+    # Builds Enumerator for while loop iteration.
+    #
+    # @yield Condition to be evaluated before each iteration, the iteration is allowed if a true value is returned.
+    #
+    # @example
+    #   def build_enumerator(params)
+    #     enumerator_builder.while query_model_xyz(params).exists?
+    #   end
+    #
+    #   def each_iteration(count, params)
+    #     query_model_xyz(params).limit(1000).delete_all
+    #   end
+    #
+    #   def query_model_xyz(params)
+    #     Xyz.where(owner_id: params[:owner_id])
+    #   end
+    #
+    def build_while_enumerator(&condition)
+      count = 0
+      enum = Enumerator.new do |yielder|
+        yielder << count += 1 while condition.call
+      end
+
+      wrap(self, enum)
+    end
+
     alias_method :once, :build_once_enumerator
     alias_method :times, :build_times_enumerator
     alias_method :array, :build_array_enumerator
@@ -190,6 +216,7 @@ def build_nested_enumerator(enums, cursor:)
     alias_method :throttle, :build_throttle_enumerator
     alias_method :csv, :build_csv_enumerator
     alias_method :nested, :build_nested_enumerator
+    alias_method :while, :build_while_enumerator
 
     private
 

test/unit/enumerator_builder_test.rb

@@ -74,6 +74,13 @@ class EnumeratorBuilderTest < ActiveSupport::TestCase
       )
     end
 
+    test_builder_method(:build_while_enumerator) do
+      count = 0
+      enumerator_builder(wraps: 3).build_while_enumerator do
+        count < 3 ? (count += 1) : false
+      end
+    end
+
     # checks that all the non-alias methods were tested
     raise "methods not tested: #{methods.inspect}" unless methods.empty?