REFACTOR: Restoring of backups and migration of uploads to S3

spec/lib/backup_restore/meta_data_handler_spec.rb

@@ -0,0 +1,81 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+require_relative 'shared_context_for_backup_restore'
+
+describe BackupRestore::MetaDataHandler do
+  include_context "shared stuff"
+
+  let!(:backup_filename) { 'discourse-2019-11-18-143242-v20191108000414.tar.gz' }
+
+  def with_metadata_file(content)
+    Dir.mktmpdir do |directory|
+      if !content.nil?
+        path = File.join(directory, BackupRestore::MetaDataHandler::METADATA_FILE)
+        File.write(path, content)
+      end
+
+      yield(directory)
+    end
+  end
+
+  def validate_metadata(filename, tmp_directory)
+    BackupRestore::MetaDataHandler.new(logger, filename, tmp_directory).validate
+  end
+
+  it "extracts metadata from file when metadata file exists" do
+    metadata = '{"source":"discourse","version":20160329101122}'
+
+    with_metadata_file(metadata) do |dir|
+      expect(validate_metadata(backup_filename, dir))
+        .to include(version: 20160329101122)
+    end
+  end
+
+  it "extracts metadata from filename when metadata file does not exist" do
+    with_metadata_file(nil) do |dir|
+      expect(validate_metadata(backup_filename, dir))
+        .to include(version: 20191108000414)
+    end
+  end
+
+  it "raises an exception when the metadata file contains invalid JSON" do
+    currupt_metadata = '{"version":20160329101122'
+
+    with_metadata_file(currupt_metadata) do |dir|
+      expect { validate_metadata(backup_filename, dir) }
+        .to raise_error(BackupRestore::MetaDataError)
+    end
+  end
+
+  it "raises an exception when the metadata file is empty" do
+    with_metadata_file('') do |dir|
+      expect { validate_metadata(backup_filename, dir) }
+        .to raise_error(BackupRestore::MetaDataError)
+    end
+  end
+
+  it "raises an exception when the filename contains no version number" do
+    filename = 'discourse-2019-11-18-143242.tar.gz'
+
+    expect { validate_metadata(filename, nil) }
+      .to raise_error(BackupRestore::MetaDataError)
+  end
+
+  it "raises an exception when the filename contains an invalid version number" do
+    filename = 'discourse-2019-11-18-143242-v123456789.tar.gz'
+
+    expect { validate_metadata(filename, nil) }
+      .to raise_error(BackupRestore::MetaDataError)
+  end
+
+  it "raises an exception when the backup's version is newer than the current version" do
+    new_backup_filename = 'discourse-2019-11-18-143242-v20191113193141.sql.gz'
+
+    BackupRestore.expects(:current_version)
+      .returns(20191025005204).once
+
+    expect { validate_metadata(new_backup_filename, nil) }
+      .to raise_error(BackupRestore::MigrationRequiredError)
+  end
+end