Add version support for rust packages

Signed-off-by: TG1999 <tushar.goel.dav@gmail.com>

Author: TG1999

package_registry/rust_versions.py

@@ -0,0 +1,46 @@
+# fetchcode is a free software tool from nexB Inc. and others.
+# Visit https://github.com/nexB/fetchcode for support and download.
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# http://nexb.com and http://aboutcode.org
+#
+# This software is licensed under the Apache License version 2.0.
+#
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at: 
+# http://apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software distributed
+# under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+# CONDITIONS OF ANY KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations under the License.
+
+import requests
+from urllib.parse import urlparse
+
+
+def build_url(package):
+    """
+    Return a URL to access the list of versions using the Crates API 
+    """
+    base_url='https://crates.io/api/v1/crates'
+    return '{}/{}'.format(base_url, package)
+
+
+def get_versions(package):
+    """
+    Return a list of crate versions given the `package` from Crate packages
+    """
+
+    url = build_url(package)
+    resp = requests.get(url)
+    
+    tags = []
+    
+    response = resp.json()
+    
+    versions = response.get('versions',[])
+    for version in versions:
+        if 'num' in version:
+            tags.append(version.get('num'))
+    
+    return tags

tests/data/rust_versions_response.json

@@ -0,0 +1,60 @@
+# fetchcode is a free software tool from nexB Inc. and others.
+# Visit https://github.com/nexB/fetchcode for support and download.
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# http://nexb.com and http://aboutcode.org
+#
+# This software is licensed under the Apache License version 2.0.
+#
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at: 
+# http://apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software distributed
+# under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+# CONDITIONS OF ANY KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations under the License.
+
+import json
+from unittest import mock
+
+from package_registry import rust_versions
+
+
+@mock.patch('package_registry.rust_versions.requests.get')
+def test_rust_versions_for_not_empty_list(mock_get):
+    package = 'rand'
+    with open('tests/data/rust_versions_response.json') as file:
+        data = file.read()
+    mock_get.return_value.json.return_value = json.loads(data)
+    response = rust_versions.get_versions(package=package)
+    tags = ['0.7.3', '0.7.2', '0.7.1', '0.7.0', '0.7.0-pre.2', '0.7.0-pre.1', '0.7.0-pre.0', '0.6.5', '0.6.4', '0.6.3', '0.6.2', '0.6.1', '0.6.0', '0.6.0-pre.1', '0.6.0-pre.0', '0.5.6', '0.5.5', '0.5.4', '0.5.3', '0.5.2', '0.5.1', '0.5.0', '0.5.0-pre.2', '0.5.0-pre.1', '0.5.0-pre.0', '0.4.6', '0.4.5', '0.4.4', '0.4.3', '0.4.2', '0.4.1', '0.4.0-pre.0', '0.3.23', '0.3.22', '0.3.21-pre.0', '0.3.20', '0.3.19', '0.3.18', '0.3.17', '0.3.16', '0.3.15', '0.3.14', '0.3.13', '0.3.12', '0.3.11', '0.3.10', '0.3.9', '0.3.8', '0.3.7', '0.3.6', '0.3.5', '0.3.4', '0.3.3', '0.3.2', '0.3.1', '0.3.0', '0.2.1', '0.2.0', '0.1.4', '0.1.3', '0.1.2', '0.1.1']
+    for tag in tags:
+        assert tag in response
+    assert '0.7.9' not in response
+
+def test_build_url():
+    package = 'libc'
+    expected = 'https://crates.io/api/v1/crates/libc'
+    url = rust_versions.build_url(package=package)
+    assert expected == url 
+
+@mock.patch('package_registry.rust_versions.requests.get')
+def test_rust_version_with_None(mock_get):
+    package = None
+    mock_get.return_value.json.return_value = {'errors': [{'detail': 'Not Found'}]}
+    response = rust_versions.get_versions(package=package)
+    assert [] == response
+
+@mock.patch('package_registry.rust_versions.requests.get')
+def test_rust_version_with_empty_package_name(mock_get):
+    package = ''
+    mock_get.return_value.json.return_value = {'errors': [{'detail': 'Not Found'}]}
+    response = rust_versions.get_versions(package=package)
+    assert [] == response
+
+@mock.patch('package_registry.rust_versions.requests.get')
+def test_rust_version_with_junk_package_name(mock_get):
+    package = '!@#$%^*&*()"ABCD1234'
+    mock_get.return_value.json.return_value = {'errors': [{'detail': 'Not Found'}]}
+    response = rust_versions.get_versions(package=package)
+    assert [] == response