diff --git a/swh/loader/package/tests/test_gnu.py b/swh/loader/package/tests/test_gnu.py
index 181e35c..2e4f979 100644
--- a/swh/loader/package/tests/test_gnu.py
+++ b/swh/loader/package/tests/test_gnu.py
@@ -1,251 +1,246 @@
 # Copyright (C) 2019 The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import os
 import re
 
 from swh.model.hashutil import hash_to_bytes
 
 from swh.loader.package.gnu import GNULoader, get_version
 from swh.loader.package.tests.common import (
     check_snapshot, check_metadata_paths
 )
 
 
 def test_get_version():
     """From url to branch name should yield something relevant
 
     """
     for url, expected_branchname in [
             ('https://gnu.org/sthg/info-2.1.0.tar.gz', '2.1.0'),
             ('https://gnu.org/sthg/info-2.1.2.zip', '2.1.2'),
             ('https://sthg.org/gnu/sthg.tar.gz', 'sthg'),
             ('https://sthg.org/gnu/DLDF-1.1.4.tar.gz', '1.1.4'),
             ('https://sthg.org/gnu/anubis-latest.tar.bz2', 'latest'),
             ('https://ftp.org/gnu/aris-w32.zip', 'w32'),
             ('https://ftp.org/gnu/aris-w32-2.2.zip', 'w32-2.2'),
             ('https://ftp.org/gnu/autogen.info.tar.gz', 'autogen.info'),
             ('https://ftp.org/gnu/crypto-build-demo.tar.gz',
              'crypto-build-demo'),
             ('https://ftp.org/gnu/clue+clio+xit.clisp.tar.gz',
              'clue+clio+xit.clisp'),
             ('https://ftp.org/gnu/clue+clio.for-pcl.tar.gz',
              'clue+clio.for-pcl'),
             ('https://ftp.org/gnu/clisp-hppa2.0-hp-hpux10.20.tar.gz',
              'hppa2.0-hp-hpux10.20'),
             ('clisp-i386-solaris2.6.tar.gz', 'i386-solaris2.6'),
             ('clisp-mips-sgi-irix6.5.tar.gz', 'mips-sgi-irix6.5'),
             ('clisp-powerpc-apple-macos.tar.gz', 'powerpc-apple-macos'),
             ('clisp-powerpc-unknown-linuxlibc6.tar.gz',
              'powerpc-unknown-linuxlibc6'),
 
             ('clisp-rs6000-ibm-aix3.2.5.tar.gz', 'rs6000-ibm-aix3.2.5'),
             ('clisp-sparc-redhat51-linux.tar.gz', 'sparc-redhat51-linux'),
             ('clisp-sparc-sun-solaris2.4.tar.gz', 'sparc-sun-solaris2.4'),
             ('clisp-sparc-sun-sunos4.1.3_U1.tar.gz',
              'sparc-sun-sunos4.1.3_U1'),
             ('clisp-2.25.1-powerpc-apple-MacOSX.tar.gz',
              '2.25.1-powerpc-apple-MacOSX'),
             ('clisp-2.27-PowerMacintosh-powerpc-Darwin-1.3.7.tar.gz',
              '2.27-PowerMacintosh-powerpc-Darwin-1.3.7'),
             ('clisp-2.27-i686-unknown-Linux-2.2.19.tar.gz',
              '2.27-i686-unknown-Linux-2.2.19'),
             ('clisp-2.28-i386-i386-freebsd-4.3-RELEASE.tar.gz',
              '2.28-i386-i386-freebsd-4.3-RELEASE'),
             ('clisp-2.28-i686-unknown-cygwin_me-4.90-1.3.10.tar.gz',
              '2.28-i686-unknown-cygwin_me-4.90-1.3.10'),
             ('clisp-2.29-i386-i386-freebsd-4.6-STABLE.tar.gz',
              '2.29-i386-i386-freebsd-4.6-STABLE'),
             ('clisp-2.29-i686-unknown-cygwin_nt-5.0-1.3.12.tar.gz',
              '2.29-i686-unknown-cygwin_nt-5.0-1.3.12'),
             ('gcl-2.5.3-ansi-japi-xdr.20030701_mingw32.zip',
              '2.5.3-ansi-japi-xdr.20030701_mingw32'),
             ('gettext-runtime-0.13.1.bin.woe32.zip', '0.13.1.bin.woe32'),
             ('sather-logo_images.tar.gz', 'sather-logo_images'),
             ('sather-specification-000328.html.tar.gz', '000328.html')
 
     ]:
         actual_branchname = get_version(url)
 
         assert actual_branchname == expected_branchname
 
 
 _expected_new_contents_first_visit = [
     'e9258d81faf5881a2f96a77ba609396f82cb97ad',
     '1170cf105b04b7e2822a0e09d2acf71da7b9a130',
     'fbd27c3f41f2668624ffc80b7ba5db9b92ff27ac',
     '0057bec9b5422aff9256af240b177ac0e3ac2608',
     '2b8d0d0b43a1078fc708930c8ddc2956a86c566e',
     '27de3b3bc6545d2a797aeeb4657c0e215a0c2e55',
     '2e6db43f5cd764e677f416ff0d0c78c7a82ef19b',
     'ae9be03bd2a06ed8f4f118d3fe76330bb1d77f62',
     'edeb33282b2bffa0e608e9d2fd960fd08093c0ea',
     'd64e64d4c73679323f8d4cde2643331ba6c20af9',
     '7a756602914be889c0a2d3952c710144b3e64cb0',
     '84fb589b554fcb7f32b806951dcf19518d67b08f',
     '8624bcdae55baeef00cd11d5dfcfa60f68710a02',
     'e08441aeab02704cfbd435d6445f7c072f8f524e',
     'f67935bc3a83a67259cda4b2d43373bd56703844',
     '809788434b433eb2e3cfabd5d591c9a659d5e3d8',
     '7d7c6c8c5ebaeff879f61f37083a3854184f6c41',
     'b99fec102eb24bffd53ab61fc30d59e810f116a2',
     '7d149b28eaa228b3871c91f0d5a95a2fa7cb0c68',
     'f0c97052e567948adf03e641301e9983c478ccff',
     '7fb724242e2b62b85ca64190c31dcae5303e19b3',
     '4f9709e64a9134fe8aefb36fd827b84d8b617ab5',
     '7350628ccf194c2c3afba4ac588c33e3f3ac778d',
     '0bb892d9391aa706dc2c3b1906567df43cbe06a2',
     '49d4c0ce1a16601f1e265d446b6c5ea6b512f27c',
     '6b5cc594ac466351450f7f64a0b79fdaf4435ad3',
     '3046e5d1f70297e2a507b98224b6222c9688d610',
     '1572607d456d7f633bc6065a2b3048496d679a31',
 ]
 
 _expected_new_directories_first_visit = [
     'daabc65ec75d487b1335ffc101c0ac11c803f8fc',
     '263be23b4a8101d3ad0d9831319a3e0f2b065f36',
     '7f6e63ba6eb3e2236f65892cd822041f1a01dd5c',
     '4db0a3ecbc976083e2dac01a62f93729698429a3',
     'dfef1c80e1098dd5deda664bb44a9ab1f738af13',
     'eca971d346ea54d95a6e19d5051f900237fafdaa',
     '3aebc29ed1fccc4a6f2f2010fb8e57882406b528',
 ]
 
 _expected_new_revisions_first_visit = {
     '44183488c0774ce3c957fa19ba695cf18a4a42b3':
     '3aebc29ed1fccc4a6f2f2010fb8e57882406b528'
 }
 
 _expected_branches_first_visit = {
     'HEAD': {
         'target_type': 'alias',
         'target': 'releases/0.1.0',
     },
     'releases/0.1.0': {
         'target_type': 'revision',
         'target': '44183488c0774ce3c957fa19ba695cf18a4a42b3',
     },
 }
 
 # hash is different then before as we changed the snapshot
 # gnu used to use `release/` (singular) instead of plural
 _expected_new_snapshot_first_visit_id = 'c419397fd912039825ebdbea378bc6283f006bf5'  # noqa
 
 
 def test_release_artifact_not_found(swh_config, requests_mock):
     package = '8sync'
     package_url = 'https://ftp.gnu.org/gnu/8sync/'
     tarballs = [{
         'date': '944729610',
         'archive': 'https://ftp.gnu.org/gnu/8sync/8sync-0.1.0.tar.gz',
     }]
 
     loader = GNULoader(package, package_url, tarballs)
     requests_mock.get(re.compile('https://'), status_code=404)
 
     actual_load_status = loader.load()
 
     assert actual_load_status == {'status': 'uneventful'}
     stats = loader.storage.stat_counters()
 
     assert {
         'content': 0,
         'directory': 0,
         'origin': 1,
         'origin_visit': 1,
         'person': 0,
         'release': 0,
         'revision': 0,
         'skipped_content': 0,
         'snapshot': 1,
     } == stats
 
     origin_visit = next(loader.storage.origin_visit_get(package_url))
     assert origin_visit['status'] == 'partial'
 
 
 def test_revision_metadata_structure(swh_config, local_get):
     package = '8sync'
     package_url = 'https://ftp.gnu.org/gnu/8sync/'
     tarballs = [{
         'date': '944729610',
         'archive': 'https://ftp.gnu.org/gnu/8sync/8sync-0.1.0.tar.gz',
     }]
 
     loader = GNULoader(package, package_url, tarballs)
 
     actual_load_status = loader.load()
     assert actual_load_status == {'status': 'eventful'}
 
     expected_revision_id = hash_to_bytes(
         '44183488c0774ce3c957fa19ba695cf18a4a42b3')
     revision = list(loader.storage.revision_get([expected_revision_id]))[0]
 
     assert revision is not None
 
-    assert isinstance(revision['metadata'], dict)
-    assert isinstance(revision['metadata']['intrinsic'], dict)
-    assert isinstance(revision['metadata']['extrinsic'], dict)
-    assert isinstance(revision['metadata']['original_artifact'], dict)
-
     check_metadata_paths(revision['metadata'], paths=[
         ('intrinsic', dict),
         ('extrinsic.provider', str),
         ('extrinsic.when', str),
         ('extrinsic.raw', dict),
         ('original_artifact.filename', str),
         ('original_artifact.length', int),
         ('original_artifact.checksums', dict),
     ])
 
 
 def test_release_artifact_no_prior_visit(swh_config, local_get):
     """With no prior visit, load a gnu project ends up with 1 snapshot
 
     """
     assert 'SWH_CONFIG_FILENAME' in os.environ  # cf. tox.ini
     package = '8sync'
     package_url = 'https://ftp.gnu.org/gnu/8sync/'
     tarballs = [{
         'date': '944729610',
         'archive': 'https://ftp.gnu.org/gnu/8sync/8sync-0.1.0.tar.gz',
     }]
 
     loader = GNULoader(package, package_url, tarballs)
 
     actual_load_status = loader.load()
 
     assert actual_load_status == {'status': 'eventful'}
 
     stats = loader.storage.stat_counters()
 
     assert {
         'content': len(_expected_new_contents_first_visit),
         'directory': len(_expected_new_directories_first_visit),
         'origin': 1,
         'origin_visit': 1,
         'person': 1,
         'release': 0,
         'revision': len(_expected_new_revisions_first_visit),
         'skipped_content': 0,
         'snapshot': 1
     } == stats
 
     expected_contents = map(hash_to_bytes, _expected_new_contents_first_visit)
     assert list(loader.storage.content_missing_per_sha1(expected_contents)) \
         == []
 
     expected_dirs = map(hash_to_bytes, _expected_new_directories_first_visit)
     assert list(loader.storage.directory_missing(expected_dirs)) == []
 
     expected_revs = map(hash_to_bytes, _expected_new_revisions_first_visit)
     assert list(loader.storage.revision_missing(expected_revs)) == []
 
     expected_snapshot = {
         'id': _expected_new_snapshot_first_visit_id,
         'branches': _expected_branches_first_visit,
     }
 
     check_snapshot(expected_snapshot, loader.storage)
diff --git a/swh/loader/package/tests/test_npm.py b/swh/loader/package/tests/test_npm.py
index 6ccf13f..3d64f63 100644
--- a/swh/loader/package/tests/test_npm.py
+++ b/swh/loader/package/tests/test_npm.py
@@ -1,530 +1,525 @@
 # Copyright (C) 2019  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 
 import json
 import os
 
 from swh.model.hashutil import hash_to_bytes
 
 from swh.loader.package.npm import (
     parse_npm_package_author, extract_npm_package_author
 )
 from swh.loader.package.tests.common import (
     DATADIR, check_snapshot, check_metadata_paths
 )
 
 from swh.loader.package.npm import NpmLoader
 
 
 def _parse_author_string_test(author_str, expected_result):
     assert parse_npm_package_author(author_str) == expected_result
     assert parse_npm_package_author(' %s' % author_str) == expected_result
     assert parse_npm_package_author('%s ' % author_str) == expected_result
 
 
 def test_parse_npm_package_author():
     _parse_author_string_test(
         'John Doe',
         {
             'name': 'John Doe'
         }
     )
 
     _parse_author_string_test(
         '<john.doe@foo.bar>',
         {
             'email': 'john.doe@foo.bar'
         }
     )
 
     _parse_author_string_test(
         '(https://john.doe)',
         {
             'url': 'https://john.doe'
         }
     )
 
     _parse_author_string_test(
         'John Doe <john.doe@foo.bar>',
         {
             'name': 'John Doe',
             'email': 'john.doe@foo.bar'
         }
     )
 
     _parse_author_string_test(
         'John Doe<john.doe@foo.bar>',
         {
             'name': 'John Doe',
             'email': 'john.doe@foo.bar'
         }
     )
 
     _parse_author_string_test(
         'John Doe (https://john.doe)',
         {
             'name': 'John Doe',
             'url': 'https://john.doe'
         }
     )
 
     _parse_author_string_test(
         'John Doe(https://john.doe)',
         {
             'name': 'John Doe',
             'url': 'https://john.doe'
         }
     )
 
     _parse_author_string_test(
         '<john.doe@foo.bar> (https://john.doe)',
         {
             'email': 'john.doe@foo.bar',
             'url': 'https://john.doe'
         }
     )
 
     _parse_author_string_test(
         '(https://john.doe) <john.doe@foo.bar>',
         {
             'email': 'john.doe@foo.bar',
             'url': 'https://john.doe'
         }
     )
 
     _parse_author_string_test(
         'John Doe <john.doe@foo.bar> (https://john.doe)',
         {
             'name': 'John Doe',
             'email': 'john.doe@foo.bar',
             'url': 'https://john.doe'
         }
     )
 
     _parse_author_string_test(
         'John Doe (https://john.doe) <john.doe@foo.bar>',
         {
             'name': 'John Doe',
             'email': 'john.doe@foo.bar',
             'url': 'https://john.doe'
         }
     )
 
     _parse_author_string_test(
         'John Doe<john.doe@foo.bar> (https://john.doe)',
         {
             'name': 'John Doe',
             'email': 'john.doe@foo.bar',
             'url': 'https://john.doe'
         }
     )
 
     _parse_author_string_test(
         'John Doe<john.doe@foo.bar>(https://john.doe)',
         {
             'name': 'John Doe',
             'email': 'john.doe@foo.bar',
             'url': 'https://john.doe'
         }
     )
 
     _parse_author_string_test('', {})
     _parse_author_string_test('<>', {})
     _parse_author_string_test(' <>', {})
     _parse_author_string_test('<>()', {})
     _parse_author_string_test('<> ()', {})
     _parse_author_string_test('()', {})
     _parse_author_string_test(' ()', {})
 
     _parse_author_string_test(
         'John Doe <> ()',
         {
             'name': 'John Doe'
         }
     )
 
     _parse_author_string_test(
         'John Doe <>',
         {
             'name': 'John Doe'
         }
     )
 
     _parse_author_string_test(
         'John Doe ()',
         {
             'name': 'John Doe'
         }
     )
 
 
 def test_extract_npm_package_author():
     package_metadata_filepath = os.path.join(
         DATADIR, 'replicate.npmjs.com', 'org_visit1')
 
     with open(package_metadata_filepath) as json_file:
         package_metadata = json.load(json_file)
 
     extract_npm_package_author(package_metadata['versions']['0.0.2']) == \
         {
             'fullname': b'mooz <stillpedant@gmail.com>',
             'name': b'mooz',
             'email': b'stillpedant@gmail.com'
         }
 
     assert (
         extract_npm_package_author(package_metadata['versions']['0.0.3']) ==
         {
             'fullname': b'Masafumi Oyamada <stillpedant@gmail.com>',
             'name': b'Masafumi Oyamada',
             'email': b'stillpedant@gmail.com'
         }
     )
 
     package_json = json.loads('''
     {
         "name": "highlightjs-line-numbers.js",
         "version": "2.7.0",
         "description": "Highlight.js line numbers plugin.",
         "main": "src/highlightjs-line-numbers.js",
         "dependencies": {},
         "devDependencies": {
             "gulp": "^4.0.0",
             "gulp-rename": "^1.4.0",
             "gulp-replace": "^0.6.1",
             "gulp-uglify": "^1.2.0"
         },
         "repository": {
             "type": "git",
             "url": "https://github.com/wcoder/highlightjs-line-numbers.js.git"
         },
         "author": "Yauheni Pakala <evgeniy.pakalo@gmail.com>",
         "license": "MIT",
         "bugs": {
             "url": "https://github.com/wcoder/highlightjs-line-numbers.js/issues"
         },
         "homepage": "http://wcoder.github.io/highlightjs-line-numbers.js/"
     }''') # noqa
 
     assert extract_npm_package_author(package_json) == \
         {
             'fullname': b'Yauheni Pakala <evgeniy.pakalo@gmail.com>',
             'name': b'Yauheni Pakala',
             'email': b'evgeniy.pakalo@gmail.com'
         }
 
     package_json = json.loads('''
     {
         "name": "3-way-diff",
         "version": "0.0.1",
         "description": "3-way diffing of JavaScript objects",
         "main": "index.js",
         "authors": [
             {
                 "name": "Shawn Walsh",
                 "url": "https://github.com/shawnpwalsh"
             },
             {
                 "name": "Markham F Rollins IV",
                 "url": "https://github.com/mrollinsiv"
             }
         ],
         "keywords": [
             "3-way diff",
             "3 way diff",
             "three-way diff",
             "three way diff"
         ],
         "devDependencies": {
             "babel-core": "^6.20.0",
             "babel-preset-es2015": "^6.18.0",
             "mocha": "^3.0.2"
         },
         "dependencies": {
             "lodash": "^4.15.0"
         }
     }''')
 
     assert extract_npm_package_author(package_json) == \
         {
             'fullname': b'Shawn Walsh',
             'name': b'Shawn Walsh',
             'email': None
         }
 
     package_json = json.loads('''
     {
         "name": "yfe-ynpm",
         "version": "1.0.0",
         "homepage": "http://gitlab.ywwl.com/yfe/yfe-ynpm",
         "repository": {
             "type": "git",
             "url": "git@gitlab.ywwl.com:yfe/yfe-ynpm.git"
         },
         "author": [
             "fengmk2 <fengmk2@gmail.com> (https://fengmk2.com)",
             "xufuzi <xufuzi@ywwl.com> (https://7993.org)"
         ],
         "license": "MIT"
     }''')
 
     assert extract_npm_package_author(package_json) == \
         {
             'fullname': b'fengmk2 <fengmk2@gmail.com>',
             'name': b'fengmk2',
             'email': b'fengmk2@gmail.com'
         }
 
     package_json = json.loads('''
     {
         "name": "umi-plugin-whale",
         "version": "0.0.8",
         "description": "Internal contract component",
         "authors": {
             "name": "xiaohuoni",
             "email": "448627663@qq.com"
         },
         "repository": "alitajs/whale",
         "devDependencies": {
             "np": "^3.0.4",
             "umi-tools": "*"
         },
         "license": "MIT"
     }''')
 
     assert extract_npm_package_author(package_json) == \
         {
             'fullname': b'xiaohuoni <448627663@qq.com>',
             'name': b'xiaohuoni',
             'email': b'448627663@qq.com'
         }
 
 
 def normalize_hashes(hashes):
     if isinstance(hashes, str):
         return hash_to_bytes(hashes)
     if isinstance(hashes, list):
         return [hash_to_bytes(x) for x in hashes]
     return {hash_to_bytes(k): hash_to_bytes(v) for k, v in hashes.items()}
 
 
 _expected_new_contents_first_visit = normalize_hashes([
     '4ce3058e16ab3d7e077f65aabf855c34895bf17c',
     '858c3ceee84c8311adc808f8cdb30d233ddc9d18',
     '0fa33b4f5a4e0496da6843a38ff1af8b61541996',
     '85a410f8ef8eb8920f2c384a9555566ad4a2e21b',
     '9163ac8025923d5a45aaac482262893955c9b37b',
     '692cf623b8dd2c5df2c2998fd95ae4ec99882fb4',
     '18c03aac6d3e910efb20039c15d70ab5e0297101',
     '41265c42446aac17ca769e67d1704f99e5a1394d',
     '783ff33f5882813dca9239452c4a7cadd4dba778',
     'b029cfb85107aee4590c2434a3329bfcf36f8fa1',
     '112d1900b4c2e3e9351050d1b542c9744f9793f3',
     '5439bbc4bd9a996f1a38244e6892b71850bc98fd',
     'd83097a2f994b503185adf4e719d154123150159',
     'd0939b4898e83090ee55fd9d8a60e312cfadfbaf',
     'b3523a26f7147e4af40d9d462adaae6d49eda13e',
     'cd065fb435d6fb204a8871bcd623d0d0e673088c',
     '2854a40855ad839a54f4b08f5cff0cf52fca4399',
     'b8a53bbaac34ebb8c6169d11a4b9f13b05c583fe',
     '0f73d56e1cf480bded8a1ecf20ec6fc53c574713',
     '0d9882b2dfafdce31f4e77fe307d41a44a74cefe',
     '585fc5caab9ead178a327d3660d35851db713df1',
     'e8cd41a48d79101977e3036a87aeb1aac730686f',
     '5414efaef33cceb9f3c9eb5c4cc1682cd62d14f7',
     '9c3cc2763bf9e9e37067d3607302c4776502df98',
     '3649a68410e354c83cd4a38b66bd314de4c8f5c9',
     'e96ed0c091de1ebdf587104eaf63400d1974a1fe',
     '078ca03d2f99e4e6eab16f7b75fbb7afb699c86c',
     '38de737da99514de6559ff163c988198bc91367a',
 ])
 
 _expected_new_directories_first_visit = normalize_hashes([
     '3370d20d6f96dc1c9e50f083e2134881db110f4f',
     '42753c0c2ab00c4501b552ac4671c68f3cf5aece',
     'd7895533ef5edbcffdea3f057d9fef3a1ef845ce',
     '80579be563e2ef3e385226fe7a3f079b377f142c',
     '3b0ddc6a9e58b4b53c222da4e27b280b6cda591c',
     'bcad03ce58ac136f26f000990fc9064e559fe1c0',
     '5fc7e82a1bc72e074665c6078c6d3fad2f13d7ca',
     'e3cd26beba9b1e02f6762ef54bd9ac80cc5f25fd',
     '584b5b4b6cf7f038095e820b99386a9c232de931',
     '184c8d6d0d242f2b1792ef9d3bf396a5434b7f7a',
     'bb5f4ee143c970367eb409f2e4c1104898048b9d',
     '1b95491047add1103db0dfdfa84a9735dcb11e88',
     'a00c6de13471a2d66e64aca140ddb21ef5521e62',
     '5ce6c1cd5cda2d546db513aaad8c72a44c7771e2',
     'c337091e349b6ac10d38a49cdf8c2401ef9bb0f2',
     '202fafcd7c0f8230e89d5496ad7f44ab12b807bf',
     '775cc516543be86c15c1dc172f49c0d4e6e78235',
     'ff3d1ead85a14f891e8b3fa3a89de39db1b8de2e',
 ])
 
 _expected_new_revisions_first_visit = normalize_hashes({
     'd8a1c7474d2956ac598a19f0f27d52f7015f117e':
     '42753c0c2ab00c4501b552ac4671c68f3cf5aece',
     '5f9eb78af37ffd12949f235e86fac04898f9f72a':
     '3370d20d6f96dc1c9e50f083e2134881db110f4f',
     'ba019b192bdb94bd0b5bd68b3a5f92b5acc2239a':
     'd7895533ef5edbcffdea3f057d9fef3a1ef845ce'}
 )
 
 _expected_new_snapshot_first_visit_id = normalize_hashes(
     'd0587e1195aed5a8800411a008f2f2d627f18e2d')
 
 _expected_branches_first_visit = {
     'HEAD': {
         'target': 'releases/0.0.4',
         'target_type': 'alias'
     },
     'releases/0.0.2': {
         'target': 'd8a1c7474d2956ac598a19f0f27d52f7015f117e',
         'target_type': 'revision'
     },
     'releases/0.0.3': {
         'target': '5f9eb78af37ffd12949f235e86fac04898f9f72a',
         'target_type': 'revision'
     },
     'releases/0.0.4': {
         'target': 'ba019b192bdb94bd0b5bd68b3a5f92b5acc2239a',
         'target_type': 'revision'
     }
 }
 
 
 def package_url(package):
     return 'https://www.npmjs.com/package/%s' % package
 
 
 def package_metadata_url(package):
     return 'https://replicate.npmjs.com/%s/' % package
 
 
 def test_revision_metadata_structure(swh_config, local_get):
     package = 'org'
     loader = NpmLoader(package,
                        package_url(package),
                        package_metadata_url(package))
 
     actual_load_status = loader.load()
     assert actual_load_status == {'status': 'eventful'}
 
     expected_revision_id = hash_to_bytes(
         'd8a1c7474d2956ac598a19f0f27d52f7015f117e')
     revision = list(loader.storage.revision_get([expected_revision_id]))[0]
 
     assert revision is not None
 
-    assert isinstance(revision['metadata'], dict)
-    assert isinstance(revision['metadata']['intrinsic'], dict)
-    assert isinstance(revision['metadata']['extrinsic'], dict)
-    assert isinstance(revision['metadata']['original_artifact'], dict)
-
     check_metadata_paths(revision['metadata'], paths=[
         ('intrinsic.tool', str),
         ('intrinsic.raw', dict),
         ('extrinsic.provider', str),
         ('extrinsic.when', str),
         ('extrinsic.raw', dict),
         ('original_artifact.filename', str),
         ('original_artifact.length', int),
         ('original_artifact.checksums', dict),
     ])
 
 
 def test_npm_loader_first_visit(swh_config, local_get):
 
     package = 'org'
     loader = NpmLoader(package,
                        package_url(package),
                        package_metadata_url(package))
 
     actual_load_status = loader.load()
     assert actual_load_status == {'status': 'eventful'}
 
     stats = loader.storage.stat_counters()
 
     assert {
         'content': len(_expected_new_contents_first_visit),
         'directory': len(_expected_new_directories_first_visit),
         'origin': 1,
         'origin_visit': 1,
         'person': 2,
         'release': 0,
         'revision': len(_expected_new_revisions_first_visit),
         'skipped_content': 0,
         'snapshot': 1,
     } == stats
 
     assert len(list(loader.storage.content_get(
         _expected_new_contents_first_visit))) == len(
             _expected_new_contents_first_visit)
 
     assert list(loader.storage.directory_missing(
         _expected_new_directories_first_visit)) == []
 
     assert list(loader.storage.revision_missing(
         _expected_new_revisions_first_visit)) == []
 
     expected_snapshot = {
         'id': _expected_new_snapshot_first_visit_id,
         'branches': _expected_branches_first_visit,
     }
     check_snapshot(expected_snapshot, loader.storage)
 
 
 def test_npm_loader_incremental_visit(swh_config, local_get_visits):
     package = 'org'
     url = package_url(package)
     metadata_url = package_metadata_url(package)
     loader = NpmLoader(package, url, metadata_url)
 
     actual_load_status = loader.load()
 
     assert actual_load_status == {'status': 'eventful'}
     origin_visit = list(loader.storage.origin_visit_get(url))[-1]
     assert origin_visit['status'] == 'full'
 
     stats = loader.storage.stat_counters()
 
     assert {
         'content': len(_expected_new_contents_first_visit),
         'directory': len(_expected_new_directories_first_visit),
         'origin': 1,
         'origin_visit': 1,
         'person': 2,
         'release': 0,
         'revision': len(_expected_new_revisions_first_visit),
         'skipped_content': 0,
         'snapshot': 1,
     } == stats
 
     loader._info = None  # reset loader internal state
     actual_load_status2 = loader.load()
 
     assert actual_load_status2 == {'status': 'eventful'}
     origin_visit2 = list(loader.storage.origin_visit_get(url))[-1]
     assert origin_visit2['status'] == 'full'
 
     stats = loader.storage.stat_counters()
 
     assert {  # 3 new releases artifacts
         'content': len(_expected_new_contents_first_visit) + 14,
         'directory': len(_expected_new_directories_first_visit) + 15,
         'origin': 1,
         'origin_visit': 2,
         'person': 2,
         'release': 0,
         'revision': len(_expected_new_revisions_first_visit) + 3,
         'skipped_content': 0,
         'snapshot': 2,
     } == stats
 
     urls = [
         m.url for m in local_get_visits.request_history
         if m.url.startswith('https://registry.npmjs.org')
     ]
     assert len(urls) == len(set(urls))  # we visited each artifact once across
diff --git a/swh/loader/package/tests/test_pypi.py b/swh/loader/package/tests/test_pypi.py
index 2b3b6b1..b2612f3 100644
--- a/swh/loader/package/tests/test_pypi.py
+++ b/swh/loader/package/tests/test_pypi.py
@@ -1,571 +1,566 @@
 # Copyright (C) 2019 The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import os
 
 from os import path
 
 import pytest
 
 from unittest.mock import patch
 
 from swh.core.tarball import uncompress
 from swh.model.hashutil import hash_to_bytes
 from swh.loader.package.pypi import (
     PyPILoader, pypi_api_url, author, extract_intrinsic_metadata
 )
 from swh.loader.package.tests.common import (
     check_snapshot, DATADIR, check_metadata_paths
 )
 
 from swh.loader.package.tests.conftest import local_get_factory
 
 
 def test_author_basic():
     data = {
         'author': "i-am-groot",
         'author_email': 'iam@groot.org',
     }
     actual_author = author(data)
 
     expected_author = {
         'fullname': b'i-am-groot <iam@groot.org>',
         'name': b'i-am-groot',
         'email': b'iam@groot.org',
     }
 
     assert actual_author == expected_author
 
 
 def test_author_empty_email():
     data = {
         'author': 'i-am-groot',
         'author_email': '',
     }
     actual_author = author(data)
 
     expected_author = {
         'fullname': b'i-am-groot',
         'name': b'i-am-groot',
         'email': b'',
     }
 
     assert actual_author == expected_author
 
 
 def test_author_empty_name():
     data = {
         'author': "",
         'author_email': 'iam@groot.org',
     }
     actual_author = author(data)
 
     expected_author = {
         'fullname': b' <iam@groot.org>',
         'name': b'',
         'email': b'iam@groot.org',
     }
 
     assert actual_author == expected_author
 
 
 def test_author_malformed():
     data = {
         'author': "['pierre', 'paul', 'jacques']",
         'author_email': None,
     }
 
     actual_author = author(data)
 
     expected_author = {
         'fullname': b"['pierre', 'paul', 'jacques']",
         'name': b"['pierre', 'paul', 'jacques']",
         'email': None,
     }
 
     assert actual_author == expected_author
 
 
 def test_author_malformed_2():
     data = {
         'author': '[marie, jeanne]',
         'author_email': '[marie@some, jeanne@thing]',
     }
 
     actual_author = author(data)
 
     expected_author = {
         'fullname': b'[marie, jeanne] <[marie@some, jeanne@thing]>',
         'name': b'[marie, jeanne]',
         'email': b'[marie@some, jeanne@thing]',
     }
 
     assert actual_author == expected_author
 
 
 def test_author_malformed_3():
     data = {
         'author': '[marie, jeanne, pierre]',
         'author_email': '[marie@somewhere.org, jeanne@somewhere.org]',
     }
 
     actual_author = author(data)
 
     expected_author = {
         'fullname': b'[marie, jeanne, pierre] <[marie@somewhere.org, jeanne@somewhere.org]>',  # noqa
         'name': b'[marie, jeanne, pierre]',
         'email': b'[marie@somewhere.org, jeanne@somewhere.org]',
     }
 
     actual_author == expected_author
 
 
 # configuration error #
 
 def test_badly_configured_loader_raise(monkeypatch):
     """Badly configured loader should raise"""
     monkeypatch.delenv('SWH_CONFIG_FILENAME', raising=False)
     with pytest.raises(ValueError) as e:
         PyPILoader(url='some-url')
 
     assert 'Misconfiguration' in e.value.args[0]
 
 
 def test_pypi_api_url():
     """Compute pypi api url from the pypi project url should be ok"""
     url = pypi_api_url('https://pypi.org/project/requests')
     assert url == 'https://pypi.org/pypi/requests/json'
 
 
 @pytest.mark.fs
 def test_extract_intrinsic_metadata(tmp_path):
     """Parsing existing archive's PKG-INFO should yield results"""
     uncompressed_archive_path = str(tmp_path)
     archive_path = path.join(
         DATADIR, 'files.pythonhosted.org', '0805nexter-1.1.0.zip')
     uncompress(archive_path, dest=uncompressed_archive_path)
 
     actual_metadata = extract_intrinsic_metadata(uncompressed_archive_path)
     expected_metadata = {
         'metadata_version': '1.0',
         'name': '0805nexter',
         'version': '1.1.0',
         'summary': 'a simple printer of nested lest',
         'home_page': 'http://www.hp.com',
         'author': 'hgtkpython',
         'author_email': '2868989685@qq.com',
         'platforms': ['UNKNOWN'],
     }
 
     assert actual_metadata == expected_metadata
 
 
 @pytest.mark.fs
 def test_extract_intrinsic_metadata_failures(tmp_path):
     """Parsing inexistant path/archive/PKG-INFO yield None"""
     # inexistant first level path
     assert extract_intrinsic_metadata('/something-inexistant') == {}
     # inexistant second level path (as expected by pypi archives)
     assert extract_intrinsic_metadata(tmp_path) == {}
     # inexistant PKG-INFO within second level path
     existing_path_no_pkginfo = str(tmp_path / 'something')
     os.mkdir(existing_path_no_pkginfo)
     assert extract_intrinsic_metadata(tmp_path) == {}
 
 
 # LOADER SCENARIO #
 
 # "edge" cases (for the same origin) #
 
 
 # no release artifact:
 # {visit full, status: uneventful, no contents, etc...}
 local_get_missing_all = local_get_factory(ignore_urls=[
     'https://files.pythonhosted.org/packages/ec/65/c0116953c9a3f47de89e71964d6c7b0c783b01f29fa3390584dbf3046b4d/0805nexter-1.1.0.zip',  # noqa
     'https://files.pythonhosted.org/packages/c4/a0/4562cda161dc4ecbbe9e2a11eb365400c0461845c5be70d73869786809c4/0805nexter-1.2.0.zip',  # noqa
 ])
 
 
 def test_no_release_artifact(swh_config, local_get_missing_all):
     """Load a pypi project with all artifacts missing ends up with no snapshot
 
     """
     url = 'https://pypi.org/project/0805nexter'
     loader = PyPILoader(url)
 
     actual_load_status = loader.load()
 
     assert actual_load_status == {'status': 'uneventful'}
 
     stats = loader.storage.stat_counters()
     assert {
         'content': 0,
         'directory': 0,
         'origin': 1,
         'origin_visit': 1,
         'person': 0,
         'release': 0,
         'revision': 0,
         'skipped_content': 0,
         'snapshot': 1,
     } == stats
 
     origin_visit = next(loader.storage.origin_visit_get(url))
     assert origin_visit['status'] == 'partial'
 
 
 # problem during loading:
 # {visit: partial, status: uneventful, no snapshot}
 
 
 def test_release_with_traceback(swh_config):
     url = 'https://pypi.org/project/0805nexter'
     with patch('swh.loader.package.pypi.PyPILoader.get_default_release',
                side_effect=ValueError('Problem')):
         loader = PyPILoader(url)
 
         actual_load_status = loader.load()
 
         assert actual_load_status == {'status': 'uneventful'}
 
         stats = loader.storage.stat_counters()
 
         assert {
             'content': 0,
             'directory': 0,
             'origin': 1,
             'origin_visit': 1,
             'person': 0,
             'release': 0,
             'revision': 0,
             'skipped_content': 0,
             'snapshot': 0,
         } == stats
 
     origin_visit = next(loader.storage.origin_visit_get(url))
     assert origin_visit['status'] == 'partial'
 
 
 # problem during loading: failure early enough in between swh contents...
 # some contents (contents, directories, etc...) have been written in storage
 # {visit: partial, status: eventful, no snapshot}
 
 # problem during loading: failure late enough we can have snapshots (some
 # revisions are written in storage already)
 # {visit: partial, status: eventful, snapshot}
 
 # "normal" cases (for the same origin) #
 
 
 local_get_missing_one = local_get_factory(ignore_urls=[
     'https://files.pythonhosted.org/packages/ec/65/c0116953c9a3f47de89e71964d6c7b0c783b01f29fa3390584dbf3046b4d/0805nexter-1.1.0.zip',  # noqa
 ])
 
 # some missing release artifacts:
 # {visit partial, status: eventful, 1 snapshot}
 
 
 def test_revision_metadata_structure(swh_config, local_get):
     url = 'https://pypi.org/project/0805nexter'
     loader = PyPILoader(url)
 
     actual_load_status = loader.load()
     assert actual_load_status == {'status': 'eventful'}
 
     expected_revision_id = hash_to_bytes(
         'e445da4da22b31bfebb6ffc4383dbf839a074d21')
     revision = list(loader.storage.revision_get([expected_revision_id]))[0]
 
     assert revision is not None
 
-    assert isinstance(revision['metadata'], dict)
-    assert isinstance(revision['metadata']['intrinsic'], dict)
-    assert isinstance(revision['metadata']['extrinsic'], dict)
-    assert isinstance(revision['metadata']['original_artifact'], dict)
-
     check_metadata_paths(revision['metadata'], paths=[
         ('intrinsic.tool', str),
         ('intrinsic.raw', dict),
         ('extrinsic.provider', str),
         ('extrinsic.when', str),
         ('extrinsic.raw', dict),
         ('original_artifact.filename', str),
         ('original_artifact.length', int),
         ('original_artifact.checksums', dict),
     ])
 
 
 def test_release_with_missing_artifact(swh_config, local_get_missing_one):
     """Load a pypi project with some missing artifacts ends up with 1 snapshot
 
     """
     url = 'https://pypi.org/project/0805nexter'
     loader = PyPILoader(url)
 
     actual_load_status = loader.load()
 
     assert actual_load_status == {'status': 'eventful'}
 
     stats = loader.storage.stat_counters()
     assert {
         'content': 3,
         'directory': 2,
         'origin': 1,
         'origin_visit': 1,
         'person': 1,
         'release': 0,
         'revision': 1,
         'skipped_content': 0,
         'snapshot': 1
     } == stats
 
     expected_contents = map(hash_to_bytes, [
         '405859113963cb7a797642b45f171d6360425d16',
         'e5686aa568fdb1d19d7f1329267082fe40482d31',
         '83ecf6ec1114fd260ca7a833a2d165e71258c338',
     ])
 
     assert list(loader.storage.content_missing_per_sha1(expected_contents))\
         == []
 
     expected_dirs = map(hash_to_bytes, [
         'b178b66bd22383d5f16f4f5c923d39ca798861b4',
         'c3a58f8b57433a4b56caaa5033ae2e0931405338',
     ])
 
     assert list(loader.storage.directory_missing(expected_dirs)) == []
 
     # {revision hash: directory hash}
     expected_revs = {
         hash_to_bytes('e445da4da22b31bfebb6ffc4383dbf839a074d21'): hash_to_bytes('b178b66bd22383d5f16f4f5c923d39ca798861b4'),  # noqa
     }
     assert list(loader.storage.revision_missing(expected_revs)) == []
 
     expected_branches = {
         'releases/1.2.0': {
             'target': 'e445da4da22b31bfebb6ffc4383dbf839a074d21',
             'target_type': 'revision',
         },
         'HEAD': {
             'target': 'releases/1.2.0',
             'target_type': 'alias',
         },
     }
 
     expected_snapshot = {
         'id': 'dd0e4201a232b1c104433741dbf45895b8ac9355',
         'branches': expected_branches,
     }
     check_snapshot(expected_snapshot, storage=loader.storage)
 
     origin_visit = next(loader.storage.origin_visit_get(url))
     assert origin_visit['status'] == 'partial'
 
 
 def test_release_artifact_no_prior_visit(swh_config, local_get):
     """With no prior visit, load a pypi project ends up with 1 snapshot
 
     """
     url = 'https://pypi.org/project/0805nexter'
     loader = PyPILoader(url)
 
     actual_load_status = loader.load()
 
     assert actual_load_status == {'status': 'eventful'}
 
     stats = loader.storage.stat_counters()
     assert {
         'content': 6,
         'directory': 4,
         'origin': 1,
         'origin_visit': 1,
         'person': 1,
         'release': 0,
         'revision': 2,
         'skipped_content': 0,
         'snapshot': 1
     } == stats
 
     expected_contents = map(hash_to_bytes, [
         'a61e24cdfdab3bb7817f6be85d37a3e666b34566',
         '938c33483285fd8ad57f15497f538320df82aeb8',
         'a27576d60e08c94a05006d2e6d540c0fdb5f38c8',
         '405859113963cb7a797642b45f171d6360425d16',
         'e5686aa568fdb1d19d7f1329267082fe40482d31',
         '83ecf6ec1114fd260ca7a833a2d165e71258c338',
     ])
 
     assert list(loader.storage.content_missing_per_sha1(expected_contents))\
         == []
 
     expected_dirs = map(hash_to_bytes, [
         '05219ba38bc542d4345d5638af1ed56c7d43ca7d',
         'cf019eb456cf6f78d8c4674596f1c9a97ece8f44',
         'b178b66bd22383d5f16f4f5c923d39ca798861b4',
         'c3a58f8b57433a4b56caaa5033ae2e0931405338',
     ])
 
     assert list(loader.storage.directory_missing(expected_dirs)) == []
 
     # {revision hash: directory hash}
     expected_revs = {
         hash_to_bytes('4c99891f93b81450385777235a37b5e966dd1571'): hash_to_bytes('05219ba38bc542d4345d5638af1ed56c7d43ca7d'),  # noqa
         hash_to_bytes('e445da4da22b31bfebb6ffc4383dbf839a074d21'): hash_to_bytes('b178b66bd22383d5f16f4f5c923d39ca798861b4'),  # noqa
     }
     assert list(loader.storage.revision_missing(expected_revs)) == []
 
     expected_branches = {
         'releases/1.1.0': {
             'target': '4c99891f93b81450385777235a37b5e966dd1571',
             'target_type': 'revision',
         },
         'releases/1.2.0': {
             'target': 'e445da4da22b31bfebb6ffc4383dbf839a074d21',
             'target_type': 'revision',
         },
         'HEAD': {
             'target': 'releases/1.2.0',
             'target_type': 'alias',
         },
     }
 
     expected_snapshot = {
         'id': 'ba6e158ada75d0b3cfb209ffdf6daa4ed34a227a',
         'branches': expected_branches,
     }
     check_snapshot(expected_snapshot, loader.storage)
 
     origin_visit = next(loader.storage.origin_visit_get(url))
     assert origin_visit['status'] == 'full'
 
 
 # release artifact, new artifact
 # {visit full, status full, new snapshot with shared history as prior snapshot}
 def test_release_artifact_incremental_visit(swh_config, local_get_visits):
     """With prior visit, 2nd load will result with a different snapshot
 
     with some shared history
 
     """
     url = 'https://pypi.org/project/0805nexter'
     loader = PyPILoader(url)
 
     visit1_actual_load_status = loader.load()
     visit1_stats = loader.storage.stat_counters()
     assert visit1_actual_load_status == {'status': 'eventful'}
     origin_visit1 = next(loader.storage.origin_visit_get(url))
     assert origin_visit1['status'] == 'full'
 
     assert {
         'content': 6,
         'directory': 4,
         'origin': 1,
         'origin_visit': 1,
         'person': 1,
         'release': 0,
         'revision': 2,
         'skipped_content': 0,
         'snapshot': 1
     } == visit1_stats
 
     # Reset internal state
     loader._info = None
 
     visit2_actual_load_status = loader.load()
     visit2_stats = loader.storage.stat_counters()
 
     assert visit2_actual_load_status == {'status': 'eventful'}
     visits = list(loader.storage.origin_visit_get(url))
     assert len(visits) == 2
     assert visits[1]['status'] == 'full'
 
     assert {
         'content': 6 + 1,     # 1 more content
         'directory': 4 + 2,   # 2 more directories
         'origin': 1,
         'origin_visit': 1 + 1,
         'person': 1,
         'release': 0,
         'revision': 2 + 1,    # 1 more revision
         'skipped_content': 0,
         'snapshot': 1 + 1,    # 1 more snapshot
     } == visit2_stats
 
     expected_contents = map(hash_to_bytes, [
         'a61e24cdfdab3bb7817f6be85d37a3e666b34566',
         '938c33483285fd8ad57f15497f538320df82aeb8',
         'a27576d60e08c94a05006d2e6d540c0fdb5f38c8',
         '405859113963cb7a797642b45f171d6360425d16',
         'e5686aa568fdb1d19d7f1329267082fe40482d31',
         '83ecf6ec1114fd260ca7a833a2d165e71258c338',
         '92689fa2b7fb4d4fc6fb195bf73a50c87c030639'
     ])
 
     assert list(loader.storage.content_missing_per_sha1(expected_contents))\
         == []
 
     expected_dirs = map(hash_to_bytes, [
         '05219ba38bc542d4345d5638af1ed56c7d43ca7d',
         'cf019eb456cf6f78d8c4674596f1c9a97ece8f44',
         'b178b66bd22383d5f16f4f5c923d39ca798861b4',
         'c3a58f8b57433a4b56caaa5033ae2e0931405338',
         'e226e7e4ad03b4fc1403d69a18ebdd6f2edd2b3a',
         '52604d46843b898f5a43208045d09fcf8731631b',
 
     ])
 
     assert list(loader.storage.directory_missing(expected_dirs)) == []
 
     # {revision hash: directory hash}
     expected_revs = {
         hash_to_bytes('4c99891f93b81450385777235a37b5e966dd1571'): hash_to_bytes('05219ba38bc542d4345d5638af1ed56c7d43ca7d'),  # noqa
         hash_to_bytes('e445da4da22b31bfebb6ffc4383dbf839a074d21'): hash_to_bytes('b178b66bd22383d5f16f4f5c923d39ca798861b4'),  # noqa
         hash_to_bytes('51247143b01445c9348afa9edfae31bf7c5d86b1'): hash_to_bytes('e226e7e4ad03b4fc1403d69a18ebdd6f2edd2b3a'),  # noqa
     }
 
     assert list(loader.storage.revision_missing(expected_revs)) == []
 
     expected_branches = {
         'releases/1.1.0': {
             'target': '4c99891f93b81450385777235a37b5e966dd1571',
             'target_type': 'revision',
         },
         'releases/1.2.0': {
             'target': 'e445da4da22b31bfebb6ffc4383dbf839a074d21',
             'target_type': 'revision',
         },
         'releases/1.3.0': {
             'target': '51247143b01445c9348afa9edfae31bf7c5d86b1',
             'target_type': 'revision',
         },
         'HEAD': {
             'target': 'releases/1.3.0',
             'target_type': 'alias',
         },
     }
     expected_snapshot = {
         'id': '2e5149a7b0725d18231a37b342e9b7c4e121f283',
         'branches': expected_branches,
     }
 
     check_snapshot(expected_snapshot, loader.storage)
 
     origin_visit = list(loader.storage.origin_visit_get(url))[-1]
     assert origin_visit['status'] == 'full'
 
     urls = [
         m.url for m in local_get_visits.request_history
         if m.url.startswith('https://files.pythonhosted.org')
     ]
     # visited each artifact once across 2 visits
     assert len(urls) == len(set(urls))
 
 
 # release artifact, no new artifact
 # {visit full, status uneventful, same snapshot as before}
 
 # release artifact, old artifact with different checksums
 # {visit full, status full, new snapshot with shared history and some new
 # different history}