Add `pkgs_dir` function.

* gd_diff.py (pkgs_dir): New function.
* tests/test_gd_diff.py (test_pkgs_dir): Test for `pkgs_dir`.

2 files changed, 23 insertions, 0 deletions

diff --git a/gd_diff.py b/gd_diff.py
index 384e92f..63621a0 100644
--- a/gd_diff.py
+++ b/gd_diff.py
@@ -229,6 +229,18 @@ def config_file():
     return os.path.join(config_dir(), 'config')
 
 
+def pkgs_dir():
+    """Return the `pkgs` directory.
+
+    As a side effect, the directory is created if it does not exist.
+    """
+    pd = os.path.join(config_dir(), 'pkgs')
+    if not os.path.isdir(pd):
+        os.mkdir(pd)
+
+    return pd
+
+
 def configured_p():
     """Returns True if gns-deb-diff is configured; False otherwise.
     """
diff --git a/tests/test_gd_diff.py b/tests/test_gd_diff.py
index ff092a2..0130482 100644
--- a/tests/test_gd_diff.py
+++ b/tests/test_gd_diff.py
@@ -247,6 +247,17 @@ class TestGdDiff(object):
                                              'gns-deb-diff', 'config'))
 
 
+    def test_pkgs_dir(self):
+        def env(e):
+            return self.test_home
+
+        with mock.patch('os.getenv', new=env):
+            pd = pkgs_dir()
+            assert_equal(pd, os.path.join(self.test_home, '.config',
+                                          'gns-deb-diff', 'pkgs'))
+            assert_equal(os.path.isdir(pd), True)
+
+
     def test_configured_p_no(self):
         def env(e):
             return self.test_home