Add option to save catalogs when catalog-diff'ing

lib/octocatalog-diff/cli/options/save_catalog.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+# Allow catalogs to be saved to a file before they are diff'd.
+# @param parser [OptionParser object] The OptionParser argument
+# @param options [Hash] Options hash being constructed; this is modified in this method.
+OctocatalogDiff::Cli::Options::Option.newoption(:save_catalog) do
+  has_weight 155
+
+  def parse(parser, options)
+    OctocatalogDiff::Cli::Options.option_globally_or_per_branch(
+      parser: parser,
+      options: options,
+      cli_name: 'save-catalog',
+      option_name: 'save_catalog',
+      desc: 'Save intermediate catalogs into files',
+      datatype: '',
+      validator: lambda do |catalog_file|
+        target_dir = File.dirname(catalog_file)
+        unless File.directory?(target_dir)
+          raise Errno::ENOENT, "Cannot save catalog to #{catalog_file} because parent directory does not exist"
+        end
+        if File.exist?(catalog_file) && !File.file?(catalog_file)
+          raise ArgumentError, "Cannot overwrite #{catalog_file} which is not a file"
+        end
+        true
+      end,
+      post_process: lambda do |opts|
+        if opts[:to_save_catalog] && opts[:to_save_catalog] == opts[:from_save_catalog]
+          raise ArgumentError, 'Cannot use the same file for --to-save-catalog and --from-save-catalog'
+        end
+      end
+    )
+  end
+end

lib/octocatalog-diff/util/catalogs.rb

@@ -197,6 +197,11 @@ def add_parallel_result(result, parallel_catalog_obj, key_task_tuple)
           if catalog.valid?
             # The catalog was successfully compiled.
             result[key] = parallel_catalog_obj.output
+
+            if task.args[:save_catalog]
+              File.open(task.args[:save_catalog], 'w') { |f| f.write(catalog.catalog_json) }
+              @logger.debug "Saved catalog to #{task.args[:save_catalog]}"
+            end
           else
             # The catalog failed, but a catalog object was returned so that better error reporting
             # can take place. In this error reporting, we will replace 'Error:' with '[Puppet Error]'

spec/octocatalog-diff/tests/cli/options/save_catalog_spec.rb

@@ -0,0 +1,70 @@
+# frozen_string_literal: true
+
+require_relative '../options_helper'
+
+describe OctocatalogDiff::Cli::Options do
+  describe '#opt_save_catalog' do
+    it 'should raise error if catalog parent directory does not exist' do
+      args = [
+        '--to-save-catalog',
+        OctocatalogDiff::Spec.fixture_path('non/exists/catalog.json')
+      ]
+      expect { run_optparse(args) }.to raise_error(Errno::ENOENT, /parent directory does not exist/)
+    end
+
+    it 'should raise error if catalog exists but is not a file' do
+      args = [
+        '--to-save-catalog',
+        OctocatalogDiff::Spec.fixture_path('repos/default')
+      ]
+      expect { run_optparse(args) }.to raise_error(ArgumentError, /Cannot overwrite/)
+    end
+
+    it 'should not raise error if catalog file already exists' do
+      args = [
+        '--to-save-catalog',
+        OctocatalogDiff::Spec.fixture_path('catalogs/catalog-1.json')
+      ]
+      result = run_optparse(args)
+      expect(result[:to_save_catalog]).to eq(OctocatalogDiff::Spec.fixture_path('catalogs/catalog-1.json'))
+    end
+
+    it 'should not raise error if catalog file does not exist' do
+      args = [
+        '--to-save-catalog',
+        OctocatalogDiff::Spec.fixture_path('catalogs/brand-new-catalog-1.json')
+      ]
+      result = run_optparse(args)
+      expect(result[:to_save_catalog]).to eq(OctocatalogDiff::Spec.fixture_path('catalogs/brand-new-catalog-1.json'))
+    end
+
+    it 'should raise error if --to-save-catalog == --from-save-catalog' do
+      args = [
+        '--to-save-catalog',
+        OctocatalogDiff::Spec.fixture_path('catalogs/brand-new-catalog-1.json'),
+        '--from-save-catalog',
+        OctocatalogDiff::Spec.fixture_path('catalogs/brand-new-catalog-1.json')
+      ]
+      expect { run_optparse(args) }.to raise_error(ArgumentError, /Cannot use the same file for/)
+    end
+
+    it 'should not raise error if --to-save-catalog and --from-save-catalog are both nil' do
+      args = []
+      result = run_optparse(args)
+      expect(result[:to_save_catalog]).to be_nil
+      expect(result[:from_save_catalog]).to be_nil
+    end
+
+    it 'should set option correctly' do
+      args = [
+        '--to-save-catalog',
+        OctocatalogDiff::Spec.fixture_path('catalogs/brand-new-catalog-1.json'),
+        '--from-save-catalog',
+        OctocatalogDiff::Spec.fixture_path('catalogs/brand-new-catalog-2.json')
+      ]
+      result = run_optparse(args)
+      expect(result[:to_save_catalog]).to eq(OctocatalogDiff::Spec.fixture_path('catalogs/brand-new-catalog-1.json'))
+      expect(result[:from_save_catalog]).to eq(OctocatalogDiff::Spec.fixture_path('catalogs/brand-new-catalog-2.json'))
+    end
+  end
+end

spec/octocatalog-diff/tests/util/catalogs_spec.rb

@@ -330,6 +330,27 @@ def valid?
       expect(result[:from]).to eq('blank')
     end
 
+    context 'saving the catalog' do
+      before(:each) { @tmpdir = Dir.mktmpdir }
+      after(:each) { OctocatalogDiff::Spec.clean_up_tmpdir(@tmpdir) }
+
+      it 'should save the catalog when requested' do
+        filename = File.join(@tmpdir, 'catalog.json')
+        options = {
+          to_catalog: OctocatalogDiff::Spec.fixture_path('catalogs/tiny-catalog.json'),
+          from_catalog: OctocatalogDiff::Spec.fixture_path('catalogs/catalog-test-file.json'),
+          from_save_catalog: filename
+        }
+
+        logger, logger_str = OctocatalogDiff::Spec.setup_logger
+        testobj = OctocatalogDiff::Util::Catalogs.new(options, logger)
+        result = testobj.send(:build_catalog_parallelizer)
+
+        expect(logger_str.string).to match(Regexp.escape("Saved catalog to #{filename}"))
+        expect(File.read(filename)).to eq(result[:from].catalog_json)
+      end
+    end
+
     it 'should format error and raise error when a catalog compile fails' do
       error_lines = [
         'Debug: You do not care about this',