REFACTOR: Simplify backup version check

Adds specs for inalid version number in metadata file.
Follow-up to c3cd2389fe

lib/backup_restore/meta_data_handler.rb

@@ -19,11 +19,7 @@ module BackupRestore
     def validate
       metadata = extract_metadata
 
-      if metadata[:version].blank?
+      if !metadata[:version].is_a?(Integer)
-        raise MetaDataError.new("Version not defined in metadata file.")
-      end
-
-      if !metadata[:version].is_a?(String) && !metadata[:version].is_a?(Integer)
         raise MetaDataError.new("Version is not in a valid format.")
       end
 

spec/lib/backup_restore/meta_data_handler_spec.rb

@@ -23,6 +23,7 @@ describe BackupRestore::MetaDataHandler do
     BackupRestore::MetaDataHandler.new(logger, filename, tmp_directory).validate
   end
 
+  context "metadata file" do
     it "extracts metadata from file when metadata file exists" do
       metadata = '{"source":"discourse","version":20160329101122}'
 
@@ -32,13 +33,6 @@ describe BackupRestore::MetaDataHandler do
       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'
 
@@ -55,6 +49,33 @@ describe BackupRestore::MetaDataHandler do
       end
     end
 
+    it "raises an exception when the metadata file contains an invalid version number" do
+      metadata = '{"source":"discourse","version":"1abcdefghijklm"}'
+
+      with_metadata_file(metadata) do |dir|
+        expect { validate_metadata(backup_filename, dir) }
+          .to raise_error(BackupRestore::MetaDataError)
+      end
+    end
+
+    it "raises an exception when the metadata file contains an empty version number" do
+      metadata = '{"source":"discourse","version":""}'
+
+      with_metadata_file(metadata) do |dir|
+        expect { validate_metadata(backup_filename, dir) }
+          .to raise_error(BackupRestore::MetaDataError)
+      end
+    end
+  end
+
+  context "filename" do
+    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 filename contains no version number" do
       filename = 'discourse-2019-11-18-143242.tar.gz'
 
@@ -64,9 +85,13 @@ describe BackupRestore::MetaDataHandler do
 
     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)
+
+      filename = 'discourse-2019-11-18-143242-v1abcdefghijklm.tar.gz'
+      expect { validate_metadata(filename, nil) }
+        .to raise_error(BackupRestore::MetaDataError)
+    end
   end
 
   it "raises an exception when the backup's version is newer than the current version" do