Do not crash if there are no deps

Signed-off-by: Philippe Ombredanne <pombredanne@nexb.com>

Author: pombredanne

gemfileparser2/__init__.py

@@ -14,6 +14,26 @@
 import os
 import re
 
+TRACE = False
+
+
+def logger_debug(*args):
+    pass
+
+
+if TRACE:
+    import logging
+    import sys
+
+    logger = logging.getLogger(__name__)
+    logging.basicConfig(stream=sys.stdout)
+    logger.setLevel(logging.DEBUG)
+
+    def logger_debug(*args):
+        return logger.debug(' '.join(isinstance(a, str) and a or repr(a) for a in args))
+
+    logger_debug = print
+
 
 class Dependency(object):
     """
@@ -157,10 +177,17 @@ def parse_gemfile(self):
                 # Gemfile contains a call to gemspec
                 gemfiledir = os.path.dirname(self.filepath)
                 gemspec_list = glob.glob(os.path.join(gemfiledir, "*.gemspec"))
+
+                if not gemspec_list:
+                    logger_debug(f"No gemspec files found: {gemspec_list}")
+                    continue
+
                 if len(gemspec_list) > 1:
-                    print("Multiple gemspec files found")
+                    logger_debug("Multiple gemspec files found")
                     continue
+
                 gemspec_file = gemspec_list[0]
+                # FIXME: the path is not used
                 self.parse_gemspec(path=os.path.join(gemfiledir, gemspec_file))
 
             elif line.startswith("gem "):

tests/data/gemspecs/arel2.gemspec

@@ -0,0 +1,22 @@
+# -*- encoding: utf-8 -*-
+
+Gem::Specification.new do |s|
+  s.name = arel2
+  s.version = "2.0.7.beta.20110429111451"
+
+  s.required_rubygems_version = Gem::Requirement.new("> 1.3.1") if s.respond_to? :required_rubygems_version=
+  s.authors = ["Aaron Patterson", "Bryan Halmkamp", "Emilio Tagua", "Nick Kallen"]
+  s.date = %q{2011-04-29}
+  s.description = %q{Arel is a SQL AST manager for Ruby.}
+  s.email = ["aaron@tenderlovemaking.com", "bryan@brynary.com", "miloops@gmail.com", "nick@example.org"]
+  s.extra_rdoc_files = ["History.txt", "MIT-LICENSE.txt", "Manifest.txt", "README.markdown"]
+  s.files = [".autotest", ".gemtest", "History.txt", "MIT-LICENSE.txt"]
+  s.homepage = %q{http://github.com/rails/arel}
+  s.rdoc_options = ["--main", "README.markdown"]
+  s.require_paths = ["lib"]
+  s.rubyforge_project = %q{arel}
+  s.rubygems_version = %q{1.6.1}
+  s.summary = %q{Arel is a SQL AST manager for Ruby}
+  s.test_files = ["test/attributes/test_attribute.rb", "test/nodes/test_as.rb"]
+
+end

tests/data/gemspecs/arel2.gemspec-expected.json

@@ -0,0 +1,8 @@
+{
+  "development": [],
+  "runtime": [],
+  "dependency": [],
+  "test": [],
+  "production": [],
+  "metrics": []
+}

tests/test_gemfileparser2.py

@@ -71,5 +71,9 @@ def test_gemspec_3():
     check_gemparser_results("gemspecs/arel.gemspec")
 
 
+def test_gemspec_no_deps():
+    check_gemparser_results("gemspecs/arel2.gemspec",  regen=False)
+
+
 def test_gemspec_4():
     check_gemparser_results("gemspecs/logstash-mixin-ecs_compatibility_support.gemspec")