Merge pull request #5 from srushe/add-thresholds-for-model-reporting

Allow models to have thresholds for reporting

README.md

@@ -133,8 +133,22 @@ config.after(:all) do
 end
 ```
 
-This is also useful if your test suite is problem-free and you would like ensure it
-stays that way.
+### Setting thresholds for Models
+
+You may have some models you would like to report on, but which should also have
+entries in the database, for example a table that is seeded or loaded with fixtures.
+In order to allow this you can provide a threshold for a Model, which is the
+maximum number of entries allowed in the database for the Model before it is
+regarded as leaky.
+
+To provide a threshold for a Model, you can can the following:
+
+```ruby
+config.after(:all) do
+  # Perform the report after each example group
+  DatabasePlumber.inspect model_thresholds: { Bar => 3 }
+end
+
 
 ## Contributing
 

lib/database_plumber/leak_finder.rb

@@ -12,12 +12,13 @@ def self.inspect(options = {})
     def initialize(options)
       @ignored_models = (options[:ignored_models] || []) + IGNORED_AR_INTERNALS
       @ignored_adapters = options[:ignored_adapters] || []
+      @model_thresholds = options[:model_thresholds] || {}
     end
 
     def inspect
       filtered_models.each_with_object({}) do |model, results|
         records = count_for(model)
-        if records > 0
+        if records > threshold_for(model)
           results[model.to_s] = records
           mop_up(model)
         end
@@ -34,6 +35,10 @@ def count_for(model)
       raise InvalidModelError, "#{model} does not have a valid table definition"
     end
 
+    def threshold_for(model)
+      @model_thresholds.key?(model) ? @model_thresholds[model].to_i : 0
+    end
+
     def mop_up(model)
       model.destroy_all
     end

lib/database_plumber/version.rb

@@ -1,3 +1,3 @@
 module DatabasePlumber
-  VERSION = '1.0.0'
+  VERSION = '1.1.0'
 end

spec/lib/database_plumber/leak_finder_spec.rb

@@ -3,7 +3,7 @@
   let(:ignored_connection)  { double(:connection, adapter_name: 'SQLite') }
 
   let(:happy_model)           { double(:happy,    name: 'Happy',        abstract_class?: nil,  connection: normal_connection,  count: 0) }
-  let(:leaky_model)           { double(:leaky,    name: 'Leaky',        abstract_class?: nil,  connection: normal_connection,  count: 1) }
+  let(:leaky_model)           { double(:leaky,    name: 'Leaky',        abstract_class?: nil,  connection: normal_connection,  count: 2) }
   let(:abstract_model)        { double(:abstract, name: 'Abstract',     abstract_class?: true, connection: normal_connection,  count: 2) }
   let(:ignored_model)         { double(:ignored,  name: 'Ignored',      abstract_class?: nil,  connection: normal_connection,  count: 3) }
   let(:ignored_adapter_model) { double(:anon,     name: 'Anon',         abstract_class?: nil,  connection: ignored_connection, count: 4) }
@@ -24,7 +24,7 @@
     context 'with no params' do
       let(:expected_leaks) do
         {
-          leaky_model.to_s => 1,
+          leaky_model.to_s => 2,
           ignored_model.to_s => 3,
           ignored_adapter_model.to_s => 4
         }
@@ -54,7 +54,7 @@
 
       let(:expected_leaks) do
         {
-          leaky_model.to_s => 1,
+          leaky_model.to_s => 2,
           ignored_adapter_model.to_s => 4
         }
       end
@@ -83,7 +83,7 @@
 
       let(:expected_leaks) do
         {
-          leaky_model.to_s => 1,
+          leaky_model.to_s => 2,
           ignored_model.to_s => 3
         }
       end
@@ -103,6 +103,86 @@
       it { expect(join_model_stub).not_to have_received(:destroy_all) }
     end
 
+    context 'with a threshold' do
+      context 'with a leaky model at the threshold' do
+        let(:options_params) do
+          {
+            ignored_models: [ignored_model],
+            ignored_adapters: [:sqlite],
+            model_thresholds: { leaky_model => 2 }
+          }
+        end
+
+        before(:each) { @leaks = described_class.inspect(options_params) }
+
+        it { expect(@leaks).to be_empty }
+
+        it { expect(ActiveRecord::SchemaMigration).not_to have_received(:destroy_all) }
+
+        it { expect(happy_model).not_to have_received(:destroy_all) }
+        it { expect(leaky_model).not_to have_received(:destroy_all) }
+
+        it { expect(ignored_model).not_to have_received(:destroy_all) }
+        it { expect(ignored_adapter_model).not_to have_received(:destroy_all) }
+
+        it { expect(join_model_stub).not_to have_received(:destroy_all) }
+      end
+
+      context 'with a leaky model below the threshold' do
+        let(:options_params) do
+          {
+            ignored_models: [ignored_model],
+            ignored_adapters: [:sqlite],
+            model_thresholds: { leaky_model => 5 }
+          }
+        end
+
+        before(:each) { @leaks = described_class.inspect(options_params) }
+
+        it { expect(@leaks).to be_empty }
+
+        it { expect(ActiveRecord::SchemaMigration).not_to have_received(:destroy_all) }
+
+        it { expect(happy_model).not_to have_received(:destroy_all) }
+        it { expect(leaky_model).not_to have_received(:destroy_all) }
+
+        it { expect(ignored_model).not_to have_received(:destroy_all) }
+        it { expect(ignored_adapter_model).not_to have_received(:destroy_all) }
+
+        it { expect(join_model_stub).not_to have_received(:destroy_all) }
+      end
+
+      context 'with a leaky model above the threshold' do
+        let(:options_params) do
+          {
+            ignored_models: [ignored_model],
+            ignored_adapters: [:sqlite],
+            model_thresholds: { leaky_model => 1 }
+          }
+        end
+
+        let(:expected_leaks) do
+          {
+            leaky_model.to_s => 2
+          }
+        end
+
+        before(:each) { @leaks = described_class.inspect(options_params) }
+
+        it { expect(@leaks).to eql(expected_leaks) }
+
+        it { expect(ActiveRecord::SchemaMigration).not_to have_received(:destroy_all) }
+
+        it { expect(happy_model).not_to have_received(:destroy_all) }
+        it { expect(leaky_model).to have_received(:destroy_all) }
+
+        it { expect(ignored_model).not_to have_received(:destroy_all) }
+        it { expect(ignored_adapter_model).not_to have_received(:destroy_all) }
+
+        it { expect(join_model_stub).not_to have_received(:destroy_all) }
+      end
+    end
+
     context 'with no leaking models in scope' do
       let(:options_params) do
         {