Merge pull request active-hash#268 from pfeiffer/refactor-relations

Refactor `Relation` and conditions to fix mutating scopes issues

README.md

@@ -212,11 +212,11 @@ Country#name=       # => sets the name
 The ActiveHash::Base.all method functions like an in-memory data store. You can save your records as ActiveHash::Relation object by using standard ActiveRecord create and save methods:
 ```ruby
 Country.all
-=> #<ActiveHash::Relation:0x00007f861e043bb0 @klass=Country, @all_records=[], @query_hash={}, @records_dirty=false>
+=> #<ActiveHash::Relation:0x00007f861e043bb0 @klass=Country, @all_records=[], @conditions=[..], @records_dirty=false>
 Country.create
 => #<Country:0x00007f861b7abce8 @attributes={:id=>1}>
 Country.all
-=> #<ActiveHash::Relation:0x00007f861b7b3628 @klass=Country, @all_records=[#<Country:0x00007f861b7abce8 @attributes={:id=>1}>], @query_hash={}, @records_dirty=false>
+=> #<ActiveHash::Relation:0x00007f861b7b3628 @klass=Country, @all_records=[#<Country:0x00007f861b7abce8 @attributes={:id=>1}>], @conditions=[..], @records_dirty=false>
 country = Country.new
 => #<Country:0x00007f861e059938 @attributes={}>
 country.new_record?
@@ -226,7 +226,7 @@ country.save
 country.new_record?
 # => false
 Country.all
-=> #<ActiveHash::Relation:0x00007f861e0ca610 @klass=Country, @all_records=[#<Country:0x00007f861b7abce8 @attributes={:id=>1}>, #<Country:0x00007f861e059938 @attributes={:id=>2}>], @query_hash={}, @records_dirty=false>
+=> #<ActiveHash::Relation:0x00007f861e0ca610 @klass=Country, @all_records=[#<Country:0x00007f861b7abce8 @attributes={:id=>1}>, #<Country:0x00007f861e059938 @attributes={:id=>2}>], @conditions=[..], @records_dirty=false>
 ```
 Notice that when adding records to the collection, it will auto-increment the id for you by default.  If you use string ids, it will not auto-increment the id.  Available methods are:
 ```

lib/active_hash.rb

@@ -13,6 +13,8 @@
 
 require 'active_hash/base'
 require 'active_hash/relation'
+require 'active_hash/condition'
+require 'active_hash/conditions'
 require 'active_file/multiple_files'
 require 'active_file/hash_and_array_files'
 require 'active_file/base'

lib/active_hash/base.rb

@@ -21,50 +21,8 @@ class FileTypeMismatchError < StandardError
   end
 
   class Base
-
     class_attribute :_data, :dirty, :default_attributes, :scopes
 
-    class WhereChain
-      def initialize(scope)
-        @scope = scope
-        @records = @scope.all
-      end
-
-      def not(options)
-        return @scope if options.blank?
-
-        # use index if searching by id
-        if options.key?(:id) || options.key?("id")
-          ids = @scope.pluck(:id) - Array.wrap(options.delete(:id) || options.delete("id"))
-          candidates = ids.map { |id| @scope.find_by_id(id) }.compact
-        end
-
-        filtered_records = (candidates || @records || []).reject do |record|
-          options.present? && match_options?(record, options)
-        end
-
-        ActiveHash::Relation.new(@scope.klass, filtered_records, {})
-      end
-
-      def match_options?(record, options)
-        options.all? do |col, match|
-          if match.kind_of?(Array)
-            match.any? { |v| normalize(v) == normalize(record[col]) }
-          else
-            normalize(record[col]) == normalize(match)
-          end
-        end
-      end
-
-      private :match_options?
-
-      def normalize(v)
-        v.respond_to?(:to_sym) ? v.to_sym : v
-      end
-
-      private :normalize
-    end
-
     if Object.const_defined?(:ActiveModel)
       extend ActiveModel::Naming
       include ActiveModel::Conversion
@@ -205,7 +163,9 @@ def create!(attributes = {})
       end
 
       def all(options = {})
-        ActiveHash::Relation.new(self, @records || [], options[:conditions] || {})
+        relation = ActiveHash::Relation.new(self, @records || [])
+        relation = relation.where!(options[:conditions]) if options[:conditions]
+        relation
       end
 
       delegate :where, :find, :find_by, :find_by!, :find_by_id, :count, :pluck, :ids, :pick, :first, :last, :order, to: :all

lib/active_hash/condition.rb

@@ -0,0 +1,44 @@
+class ActiveHash::Relation::Condition
+  attr_reader :constraints, :inverted
+
+  def initialize(constraints)
+    @constraints = constraints
+    @inverted = false
+  end
+
+  def invert!
+    @inverted = !inverted
+
+    self
+  end
+
+  def matches?(record)
+    match = begin
+      return true unless constraints
+
+      expectation_method = inverted ? :any? : :all?
+
+      constraints.send(expectation_method) do |attribute, expected|
+        value = record.public_send(attribute)
+
+        matches_value?(value, expected)
+      end
+    end
+
+    inverted ? !match : match
+  end
+
+  private
+
+  def matches_value?(value, comparison)
+    return comparison.any? { |v| matches_value?(value, v) } if comparison.is_a?(Array)
+    return comparison.cover?(value) if comparison.is_a?(Range)
+    return comparison.match?(value) if comparison.is_a?(Regexp)
+
+    normalize(value) == normalize(comparison)
+  end
+
+  def normalize(value)
+    value.respond_to?(:to_s) ? value.to_s : value
+  end
+end

lib/active_hash/conditions.rb

@@ -0,0 +1,21 @@
+class ActiveHash::Relation::Conditions
+  attr_reader :conditions
+
+  delegate :<<, :map, to: :conditions
+
+  def initialize(conditions = [])
+    @conditions = conditions
+  end
+
+  def matches?(record)
+    conditions.all? do |condition|
+      condition.matches?(record)
+    end
+  end
+
+  def self.wrap(conditions)
+    return conditions if conditions.is_a?(self)
+
+    new(conditions)
+  end
+end