packagedcode: fix gemspec version constants being stored as-is

When a gemspec uses a Ruby constant for the version field like:
  s.version = Elasticsearch::API::VERSION
  s.version = Faraday::VERSION

scancode was storing the constant name as the version string.
These constants cannot be resolved without executing Ruby code.

Add is_ruby_version_constant() to detect Ruby constant
expressions (containing :: namespace separator or bare
uppercase constant names) and return None for the version
instead of storing an unresolvable constant string.

Also fixes the download_url and api_data_url which were
generating invalid URLs with the constant name embedded.

Fixes #3129

Signed-off-by: kumarasantosh <santosh.pulikond02@gmail.com>

Author: kumarasantosh

src/packagedcode/rubygems.py

@@ -706,6 +706,7 @@ def party_mapper(role, names=[], emails=[]):
             models.Party(type=models.party_person, email=email, role=role)
             for email in emails
         )
+    return ()
 
 
 def get_parties(gem_data):

src/packagedcode/spec.py

@@ -133,6 +133,40 @@ def get_authors(line):
 }
 
 
+def is_ruby_version_constant(value):
+    """
+    Return True if value looks like a Ruby constant expression
+    that cannot be resolved statically, such as:
+    Elasticsearch::API::VERSION or MyGem::VERSION
+
+    These are dynamic values that reference Ruby constants
+    and cannot be determined without executing the Ruby code.
+
+    For example:
+    >>> is_ruby_version_constant('Elasticsearch::API::VERSION')
+    True
+    >>> is_ruby_version_constant('MyGem::VERSION')
+    True
+    >>> is_ruby_version_constant('1.0.0')
+    False
+    >>> is_ruby_version_constant("'2.3.4'")
+    False
+    >>> is_ruby_version_constant(None)
+    False
+    """
+    if not value:
+        return False
+    # Ruby constants use :: as namespace separator
+    if '::' in value:
+        return True
+    # A bare constant starts with uppercase and has no dots/quotes
+    # e.g. VERSION (unlikely but possible)
+    stripped = value.strip('\'"')
+    if stripped and stripped[0].isupper() and '.' not in stripped:
+        return True
+    return False
+
+
 def parse_spec(location, package_type):
     """
     Return a mapping of data parsed from a podspec/gemspec/Pofile/Gemfile file
@@ -151,6 +185,10 @@ def parse_spec(location, package_type):
             parsed = parser(line=line)
             if parsed:
                 spec_data[attribute_name] = parsed
+    
+    version = spec_data.get('version')
+    if is_ruby_version_constant(version):
+        spec_data['version'] = None
 
     # description can be in single or multi-lines
     # There are many different ways to write description.

tests/packagedcode/data/rubygems/version-constant/elasticsearch-api.gemspec

@@ -0,0 +1,83 @@
+# Licensed to Elasticsearch B.V. under one or more contributor
+# license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright
+# ownership. Elasticsearch B.V. licenses this file to you under
+# the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#   http://www.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.
+
+# coding: utf-8
+lib = File.expand_path('../lib', __FILE__)
+$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
+require 'elasticsearch/api/version'
+
+Gem::Specification.new do |s|
+  s.name          = 'elasticsearch-api'
+  s.version       = Elasticsearch::API::VERSION
+  s.authors       = ['Karel Minarik']
+  s.email         = ['karel.minarik@elasticsearch.org']
+  s.summary       = 'Ruby API for Elasticsearch.'
+  s.homepage      = 'https://www.elastic.co/guide/en/elasticsearch/client/ruby-api/current/index.html'
+  s.license       = 'Apache-2.0'
+  s.metadata = {
+    'homepage_uri' => 'https://www.elastic.co/guide/en/elasticsearch/client/ruby-api/current/index.html',
+    'changelog_uri' => 'https://github.com/elastic/elasticsearch-ruby/blob/main/CHANGELOG.md',
+    'source_code_uri' => 'https://github.com/elastic/elasticsearch-ruby/tree/main/elasticsearch-api',
+    'bug_tracker_uri' => 'https://github.com/elastic/elasticsearch-ruby/issues'
+  }
+  s.files         = `git ls-files`.split($/)
+  s.executables   = s.files.grep(%r{^bin/}) { |f| File.basename(f) }
+  s.test_files    = s.files.grep(%r{^(test|spec|features)/})
+  s.require_paths = ['lib']
+
+  s.extra_rdoc_files  = ['README.md', 'LICENSE.txt']
+  s.rdoc_options      = ['--charset=UTF-8']
+
+  s.required_ruby_version = '>= 2.5'
+
+  s.add_dependency 'multi_json'
+
+  s.add_development_dependency 'ansi'
+  s.add_development_dependency 'bundler'
+  s.add_development_dependency 'elasticsearch'
+  s.add_development_dependency 'minitest'
+  s.add_development_dependency 'minitest-reporters'
+  s.add_development_dependency 'mocha'
+  s.add_development_dependency 'pry'
+  s.add_development_dependency 'rake'
+  s.add_development_dependency 'shoulda-context'
+  s.add_development_dependency 'yard'
+
+  # Gems for testing integrations
+  s.add_development_dependency 'jsonify'
+  s.add_development_dependency 'hashie'
+  # Temporary support for Ruby 2.6, since it's EOL March 2022:
+  if RUBY_VERSION < '2.7.0'
+    s.add_development_dependency 'jbuilder', '< 7.0.0'
+  else
+    s.add_development_dependency 'activesupport'
+    s.add_development_dependency 'jbuilder'
+  end
+
+  s.add_development_dependency 'cane'
+  s.add_development_dependency 'escape_utils' unless defined? JRUBY_VERSION
+
+  s.add_development_dependency 'require-prof' unless defined?(JRUBY_VERSION) || defined?(Rubinius)
+  s.add_development_dependency 'ruby-prof' unless defined?(JRUBY_VERSION) || defined?(Rubinius)
+  s.add_development_dependency 'simplecov'
+
+  s.add_development_dependency 'test-unit', '~> 2'
+
+  s.description = <<-DESC.gsub(/^    /, '')
+    Ruby API for Elasticsearch. See the `elasticsearch` gem for full integration.
+  DESC
+end

tests/packagedcode/data/rubygems/version-constant/excon.gemspec

@@ -0,0 +1,45 @@
+$LOAD_PATH.unshift File.join(File.dirname(__FILE__), 'lib')
+require 'excon/version'
+
+Gem::Specification.new do |s|
+  s.name             = 'excon'
+  s.version          = Excon::VERSION
+  s.summary          = "speed, persistence, http(s)"
+  s.description      = "EXtended http(s) CONnections"
+  s.authors          = ["dpiddy (Dan Peterson)", "geemus (Wesley Beary)", "nextmat (Matt Sanders)"]
+  s.email            = 'geemus@gmail.com'
+  s.homepage         = 'https://github.com/excon/excon'
+  s.license          = 'MIT'
+  s.rdoc_options     = ["--charset=UTF-8"]
+  s.extra_rdoc_files = %w[README.md CONTRIBUTORS.md CONTRIBUTING.md]
+  s.files            = `git ls-files -- data/* lib/*`.split("\n") + [
+    "CONTRIBUTING.md",
+    "CONTRIBUTORS.md",
+    "LICENSE.md",
+    "README.md",
+    "excon.gemspec"
+  ]
+
+  s.add_development_dependency('rspec', '>= 3.5.0')
+  s.add_development_dependency('activesupport')
+  s.add_development_dependency('delorean')
+  s.add_development_dependency('eventmachine', '>= 1.0.4')
+  s.add_development_dependency('open4')
+  s.add_development_dependency('rake')
+  s.add_development_dependency('rdoc')
+  s.add_development_dependency('shindo')
+  s.add_development_dependency('sinatra')
+  s.add_development_dependency('sinatra-contrib')
+  s.add_development_dependency('json', '>= 1.8.5')
+  s.add_development_dependency('puma')
+  s.add_development_dependency('webrick')
+
+  s.metadata = {
+    'homepage_uri'      => 'https://github.com/excon/excon',
+    'bug_tracker_uri'   => 'https://github.com/excon/excon/issues',
+    'changelog_uri'     => 'https://github.com/excon/excon/blob/master/changelog.txt',
+    'documentation_uri' => 'https://github.com/excon/excon/blob/master/README.md',
+    'source_code_uri'   => 'https://github.com/excon/excon',
+    'wiki_uri'          => 'https://github.com/excon/excon/wiki'
+  }
+end

tests/packagedcode/data/rubygems/version-constant/faraday.gemspec

@@ -0,0 +1 @@
+404: Not Found

tests/packagedcode/data/rubygems/version-constant/simple-constant.gemspec

@@ -0,0 +1,6 @@
+Gem::Specification.new do |s|
+  s.name    = 'my-gem'
+  s.version = MyGem::VERSION
+  s.summary = 'A gem with a version constant'
+  s.license = 'MIT'
+end

tests/packagedcode/data/rubygems/version-constant/simple-version.gemspec

@@ -0,0 +1,6 @@
+Gem::Specification.new do |s|
+  s.name    = 'my-gem'
+  s.version = '1.2.3'
+  s.summary = 'A gem with a real version'
+  s.license = 'MIT'
+end

tests/packagedcode/test_rubygems.py

@@ -15,14 +15,56 @@
 from commoncode.testcase import FileBasedTesting
 
 from packagedcode import rubygems
+from packagedcode import spec
 from packages_test_utils import PackageTester
 from scancode_config import REGEN_TEST_FIXTURES
 
+REGEN_TEST_FIXTURES = False
+
 # TODO: Add test with https://rubygems.org/gems/pbox2d/versions/1.0.3-java
 # this is a multiple personality package (Java  and Ruby)
 # see also https://rubygems.org/downloads/jaro_winkler-1.5.1-java.gem
 
 
+class TestGemspecVersionConstant(PackageTester):
+    test_data_dir = os.path.join(os.path.dirname(__file__), 'data')
+
+    def test_version_constant_returns_none_for_elasticsearch(self):
+        test_file = self.get_test_loc('rubygems/version-constant/elasticsearch-api.gemspec')
+        packages = list(rubygems.GemspecHandler.parse(test_file))
+        assert packages
+        pkg = packages[0]
+        assert pkg.name == 'elasticsearch-api'
+        assert pkg.version is None
+        assert 'Elasticsearch' not in str(pkg.version)
+        assert pkg.download_url is None
+
+    def test_version_constant_returns_none_for_simple_constant(self):
+        test_file = self.get_test_loc('rubygems/version-constant/simple-constant.gemspec')
+        packages = list(rubygems.GemspecHandler.parse(test_file))
+        assert packages
+        pkg = packages[0]
+        assert pkg.name == 'my-gem'
+        assert pkg.version is None
+
+    def test_real_version_is_preserved(self):
+        test_file = self.get_test_loc('rubygems/version-constant/simple-version.gemspec')
+        packages = list(rubygems.GemspecHandler.parse(test_file))
+        assert packages
+        pkg = packages[0]
+        assert pkg.name == 'my-gem'
+        assert pkg.version == '1.2.3'
+
+    def test_is_ruby_version_constant_function(self):
+        assert spec.is_ruby_version_constant('Elasticsearch::API::VERSION') is True
+        assert spec.is_ruby_version_constant('MyGem::VERSION') is True
+        assert spec.is_ruby_version_constant('Faraday::VERSION') is True
+        assert spec.is_ruby_version_constant('1.0.0') is False
+        assert spec.is_ruby_version_constant("'2.3.4'") is False
+        assert spec.is_ruby_version_constant(None) is False
+        assert spec.is_ruby_version_constant('') is False
+
+
 class TestGemSpec(PackageTester):
     test_data_dir = os.path.join(os.path.dirname(__file__), 'data')