Adding tests for package.extract_file

fixes #221

This commit adds 4 tests and fixes to make the tests pass.

There are 2 specific bugs that this commit fixes:

1) when calling extract_file with a relative_path (i.e request
to extract a single file, not an aip)  on an
uncompressed aip, a single file is now returned.  Previously the
entire aip was returned

2) when calling extract_file with a relative_path and the requested
file does not exist, an error is raised.

storage_service/locations/fixtures/package.json

@@ -114,7 +114,25 @@
         "status": "Uploaded",
         "misc_attributes": "{}"
     }
-},{
+},
+{
+ "pk": 7,
+    "model": "locations.package",
+    "fields": {
+        "uuid": "88deec53-c7dc-4828-865c-7356386e9399",
+        "description": "Small bagged 7zipped package",
+        "origin_pipeline": null,
+        "current_location": "615103f0-0ee0-4a12-ba17-43192d1143ea",
+        "current_path": "working_bag.7z",
+        "pointer_file_location": "",
+        "pointer_file_path": "",
+        "size": 595,
+        "package_type": "AIP",
+        "status": "Uploaded",
+        "misc_attributes": "{}"
+    }
+},
+{
     "pk": 1,
     "model": "locations.file",
     "fields": {

storage_service/locations/models/package.py

@@ -510,10 +510,11 @@ def extract_file(self, relative_path='', extract_path=None):
         Returns path to the extracted file and a temp dir that needs to be
         deleted.
         """
+        ss_internal = Location.active.get(purpose=Location.STORAGE_SERVICE_INTERNAL)
+        full_path = self.fetch_local_path()
+
         if extract_path is None:
-            ss_internal = Location.active.get(purpose=Location.STORAGE_SERVICE_INTERNAL)
             extract_path = tempfile.mkdtemp(dir=ss_internal.full_path)
-        full_path = self.fetch_local_path()
 
         # The basename is the base directory containing a package
         # like an AIP inside the compressed file.
@@ -553,17 +554,21 @@ def extract_file(self, relative_path='', extract_path=None):
             if relative_path:
                 command.append(relative_path)
             LOGGER.info('Extracting file with: %s to %s', command, output_path)
-            rc = subprocess.call(command)
-            LOGGER.debug('Extract file RC: %s', rc)
-            if rc:
+            rc = subprocess.check_output(command)
+            if 'No files extracted' in rc:
                 raise StorageException(_('Extraction error'))
         else:
-            LOGGER.info('Copying AIP from: %s to %s', full_path, output_path)
-            shutil.copytree(full_path, output_path)
+            if relative_path:
+                # copy only one file out of aip
+                head, tail = os.path.split(full_path)
+                src = os.path.join(head, relative_path)
+                os.mkdir(os.path.join(extract_path, basename))
+                shutil.copy(src, output_path)
+            else:
+                src = full_path
+                shutil.copytree(full_path, output_path)
 
-        if not relative_path:
-            self.local_path_location = ss_internal
-            self.local_path = output_path
+            LOGGER.info('Copying from: %s to %s', src, output_path)
 
         return (output_path, extract_path)
 

storage_service/locations/tests/test_package.py

@@ -1,4 +1,7 @@
 import os
+import pytest
+import shutil
+import tempfile
 import vcr
 
 from django.test import TestCase
@@ -25,6 +28,11 @@ def setUp(self):
         # Arkivum space points at fixtures directory
         models.Space.objects.filter(uuid='6fb34c82-4222-425e-b0ea-30acfd31f52e').update(path=FIXTURES_DIR)
 
+        self.tmp_dir = tempfile.mkdtemp()
+
+    def tearDown(self):
+        shutil.rmtree(self.tmp_dir)
+
     def test_parsing_mets_data(self):
         mets_data = self.package._parse_mets(prefix=self.mets_path)
         assert mets_data['transfer_uuid'] == 'de1b31fa-97dd-48e0-8417-03be78359531'
@@ -134,3 +142,43 @@ def test_fixity_force_local(self):
         assert failures == []
         assert message == ''
         assert timestamp is None
+
+    def test_extract_file_aip_from_uncompressed_aip(self):
+        """ It should return an aip """
+        package = models.Package.objects.get(uuid='0d4e739b-bf60-4b87-bc20-67a379b28cea')
+        basedir = package.get_base_directory()
+        output_path, extract_path = package.extract_file(extract_path=self.tmp_dir)
+        assert output_path == os.path.join(self.tmp_dir, basedir)
+        assert os.path.join(output_path, 'manifest-md5.txt')
+
+    def test_extract_file_file_from_uncompressed_aip(self):
+        """ It should return a single file from an uncompressed aip """
+        package = models.Package.objects.get(uuid='0d4e739b-bf60-4b87-bc20-67a379b28cea')
+        basedir = package.get_base_directory()
+        output_path, extract_path = package.extract_file(relative_path='working_bag/manifest-md5.txt', extract_path=self.tmp_dir)
+        assert output_path == os.path.join(self.tmp_dir, basedir, 'manifest-md5.txt')
+        assert os.path.isfile(output_path)
+
+    def test_extract_file_file_from_compressed_aip(self):
+        """ It should return a single file from a 7zip compressed aip """
+        package = models.Package.objects.get(uuid='88deec53-c7dc-4828-865c-7356386e9399')
+        basedir = package.get_base_directory()
+        output_path, extract_path = package.extract_file(relative_path='working_bag/manifest-md5.txt', extract_path=self.tmp_dir)
+        assert output_path == os.path.join(extract_path, basedir, 'manifest-md5.txt')
+        assert os.path.isfile(output_path)
+
+    def test_extract_file_file_does_not_exist_compressed(self):
+        """ It should raise an error because the requested file does not exist"""
+        package = models.Package.objects.get(uuid='88deec53-c7dc-4828-865c-7356386e9399')
+        with pytest.raises(Exception) as e_info:
+            output_path, extract_path = package.extract_file(relative_path='working_bag/manifest-sha512.txt', extract_path=self.tmp_dir)
+
+        assert e_info.value.message == 'Extraction error'
+
+    def test_extract_file_aip_from_compressed_aip(self):
+        """ It should return an aip """
+        package = models.Package.objects.get(uuid='88deec53-c7dc-4828-865c-7356386e9399')
+        basedir = package.get_base_directory()
+        output_path, extract_path = package.extract_file(extract_path=self.tmp_dir)
+        assert output_path == os.path.join(self.tmp_dir, basedir)
+        assert os.path.join(output_path, 'manifest-md5.txt')