A promising approach to complete db stubbing

4 files changed, 194 insertions, 0 deletions

diff --git a/spec/models/faster_specs_spec.rb b/spec/models/faster_specs_spec.rb
new file mode 100644
index 000000000..2c97d1055
--- /dev/null
+++ b/spec/models/faster_specs_spec.rb
@@ -0,0 +1,50 @@
+RSpec.describe 'Faster Specs', type: :faster do
+  
+  shared_examples_for 'correct behavior' do
+
+    it 'finds workbench' do
+      expect( referential.workbench ).to eq(workbench)
+    end
+
+    it 'finds referentials' do
+      expect( workbench.referentials ).to eq([referential])
+    end
+
+  end
+
+  context 'in DB' do 
+    let( :workbench ){ create :workbench }
+    let( :referential ){ create(:referential, workbench: workbench) }
+    
+    it_behaves_like 'correct behavior'
+  end
+
+  context 'stubbed' do 
+    let( :workbench ){ stub_model Workbench }
+    let( :referential ){ stub_model( Referential, workbench: workbench ) }
+    
+    it_behaves_like 'correct behavior'
+
+    context 'workbench belongs to organisation' do
+      it 'workbench has no orgnaisation' do
+        expect( workbench.organisation ).to be_nil
+      end
+      it 'but it can be set' do
+        organisation = stub_model Organisation
+        workbench.organisation = organisation
+        expect( workbench.organisation ).to eq(organisation)
+      end
+      it 'and by setting it we get the reverse relation working' do
+        organisation = stub_model Organisation
+        workbench.organisation = organisation
+        expect( organisation.workbenches ).to be_eql([workbench])
+      end
+      it 'can also be constructed that way' do
+        organisation = stub_model Organisation
+        workbench    = stub_model Workbench, organisation: organisation
+        expect( workbench.organisation ).to eq(organisation)
+        expect( organisation.workbenches ).to be_eql([workbench])
+      end
+    end
+  end
+end
diff --git a/spec/support/faster/model_stubber.rb b/spec/support/faster/model_stubber.rb
new file mode 100644
index 000000000..789f5c2d2
--- /dev/null
+++ b/spec/support/faster/model_stubber.rb
@@ -0,0 +1,15 @@
+require_relative 'model_stubber/implementation'
+
+module ModelStubber
+  def stub_model klass, **params
+    klass.new.tap do | model |
+      Implementation.new(model, params).setup
+    end
+  end
+end
+
+
+RSpec.configure do | conf |
+  # Empty Helper's cache before each example or create a helper?
+  conf.include ModelStubber, type: :faster
+end
diff --git a/spec/support/faster/model_stubber/implementation.rb b/spec/support/faster/model_stubber/implementation.rb
new file mode 100644
index 000000000..9ee1f417a
--- /dev/null
+++ b/spec/support/faster/model_stubber/implementation.rb
@@ -0,0 +1,106 @@
+require_relative './object_cache'
+
+module ModelStubber
+
+  # Get out of RSpec's example's namespace
+  class Implementation
+
+    attr_reader :model, :params
+
+    def initialize model, **params
+      @model  = model
+      @params = params
+    end
+
+    def setup
+      ObjectCache.add_to_cache model
+      stub_all_relations
+      params.each(&method(:setup_att))
+      self
+    end
+
+
+    private
+
+    # Workers
+    def setup_att key, value
+      setup_reflection( model, key, value) && return
+    end
+
+    def setup_belongs_to reflection, model, key, value
+      model.stub(key){value}
+      has_manys = 
+        value.class.reflect_on_all_associations(:has_many).select{|v| v.foreign_type == "#{model.class.name.underscore.pluralize}_type" }
+      has_manys.each do | has_many |
+        value.send( has_many.name ) << model
+      end
+      true
+    end
+
+    def setup_reflection model, key, value
+      case reflection = model.class.reflections[key.to_s]
+      when ActiveRecord::Reflection::BelongsToReflection
+        setup_belongs_to reflection, model, key, value
+      # when ActiveRecord::Reflection::HasManyReflection
+      #   setup_has_many reflection, model, key, value
+      else
+        false
+      end
+    end
+
+
+    def stub_all_relations
+      reflections.each(&method(:stub_relation))
+    end
+
+    def stub_belongs_to name
+      singleton.send :attr_reader, name
+      define_singleton_method "#{name}=" do |value| 
+        instance_variable_set("@#{name}", value) 
+        has_manys = 
+          value.class.reflect_on_all_associations(:has_many).select{|v| v.foreign_type == "#{self.class.name.underscore.pluralize}_type" }
+        has_manys.each do | has_many |
+          value.send( has_many.name ) << self
+        end
+        value
+      end
+    end
+
+    def stub_has_many name
+      empty = []
+      mystub(model, name){empty}
+    end
+
+    def stub_relation name, reflection
+      case reflection
+      when ActiveRecord::Reflection::BelongsToReflection
+        stub_belongs_to name
+      when ActiveRecord::Reflection::HasManyReflection
+        stub_has_many name 
+      end
+      
+    end
+
+    # Meta
+    def define_singleton_method name, &blk
+      singleton.module_eval do
+        define_method(name, &blk)
+      end
+    end
+    def mystub rcv, name, &blk
+      class << rcv; self end
+        .module_eval do
+          define_method(name, &blk)
+        end
+    end
+
+    # Lazy Values
+    def reflections
+      @__reflections__ ||= model.class.reflections
+    end
+
+    def singleton
+      @__singleton__ ||= class << model; self end
+    end
+  end
+end
diff --git a/spec/support/faster/model_stubber/object_cache.rb b/spec/support/faster/model_stubber/object_cache.rb
new file mode 100644
index 000000000..5749be76f
--- /dev/null
+++ b/spec/support/faster/model_stubber/object_cache.rb
@@ -0,0 +1,23 @@
+module ModelStubber
+  module ObjectCache extend self
+
+    def add_to_cache model
+      model.id = cache[model.class].keys.last.try(:succ) || 1
+      cache[model.class].update( model.id => model )
+    end
+
+    def empty_cache!
+       @__cache__ = _cache
+    end
+
+    private
+
+    def cache
+       @__cache__ ||= _cache 
+    end
+    def _cache
+      Hash.new { |h, k| h[k] = {} }
+    end
+
+  end
+end