Workbench: Ensure `output` attr is initialised when creating workbench

Since all `Workbench`es must have an associated `ReferentialSuite` via
`output`, if none is provided when creating a new `Workbench`, create
one automatically.

This is done in a `before_validation` callback (eck, AR callbacks).

In order for our prior 'should validate_presence_of' test to continue to
work, we have to work around the new callback, otherwise Shoulda can't
set `output` to `nil` to run its expectation and the test fails.

Refs #3520

2 files changed, 32 insertions, 1 deletions

diff --git a/app/models/workbench.rb b/app/models/workbench.rb
index b4852b9d5..fe4e6cce1 100644
--- a/app/models/workbench.rb
+++ b/app/models/workbench.rb
@@ -19,6 +19,8 @@ class Workbench < ActiveRecord::Base
   has_many :referentials
   has_many :referential_metadatas, through: :referentials, source: :metadatas
 
+  before_validation :initialize_output
+
 
   def all_referentials
     if line_ids.empty?
@@ -28,4 +30,12 @@ class Workbench < ActiveRecord::Base
     end
   end
 
+  private
+
+  def initialize_output
+    # Don't reset `output` if it's already initialised
+    return if !output.nil?
+
+    self.output = ReferentialSuite.create
+  end
 end
diff --git a/spec/models/workbench_spec.rb b/spec/models/workbench_spec.rb
index f83342f75..653b896dc 100644
--- a/spec/models/workbench_spec.rb
+++ b/spec/models/workbench_spec.rb
@@ -20,7 +20,14 @@ RSpec.describe Workbench, :type => :model do
 
   it { should have_many(:stop_areas).through(:stop_area_referential) }
 
-  it { should validate_presence_of(:output) }
+  it do
+    # This callback interferes with the validation test
+    Workbench.skip_callback(:validation, :before, :initialize_output)
+
+    should validate_presence_of(:output)
+
+    Workbench.set_callback(:validation, :before, :initialize_output)
+  end
 
   context '.lines' do
     let!(:ids) { ['STIF:CODIFLIGNE:Line:C00840', 'STIF:CODIFLIGNE:Line:C00086'] }
@@ -36,4 +43,18 @@ RSpec.describe Workbench, :type => :model do
       expect(lines.map(&:objectid)).to include(*ids)
     end
   end
+
+  describe ".create" do
+    it "must automatically create a ReferentialSuite when being created" do
+      workbench = Workbench.create
+      expect(workbench.output).to be_an_instance_of(ReferentialSuite)
+    end
+
+    it "must not overwrite a given ReferentialSuite" do
+      referential_suite = ReferentialSuite.create
+      workbench = Workbench.create(output: referential_suite)
+
+      expect(workbench.output).to eq(referential_suite)
+    end
+  end
 end