Refine dependency resolution algorithm so it won't take exponential time,

or bomb on cyclic dependencies.  (But it's still an untested sketch.)
Added list of things that need to be implemented before dependency
resolution can actually work.  Added tests for lower-level parts of the
dependency resolution system, and a hook to support subclasses doing
automatic download of needed dependencies.

--HG--
branch : setuptools
extra : convert_revision : svn%3A6015fed2-1504-0410-9fe1-9d1591cc4771/sandbox/trunk/setuptools%4041006

1 files changed, 51 insertions, 10 deletions

diff --git a/setuptools/tests/test_resources.py b/setuptools/tests/test_resources.py
index 52197fe9..c90b907d 100644
--- a/setuptools/tests/test_resources.py
+++ b/setuptools/tests/test_resources.py
@@ -39,6 +39,47 @@ class DistroTests(TestCase):
             [dist.version for dist in ad['FooPkg']], ['1.9','1.4','1.2']
         )
 
+        path = []
+        req, = parse_requirements("FooPkg>=1.3")
+
+        # Nominal case: no distros on path, should yield all applicable
+        self.assertEqual(ad.best_match(req,path).version, '1.9')
+
+        # If a matching distro is already installed, should return only that
+        path.append("FooPkg-1.4-py2.4-win32.egg")
+        self.assertEqual(ad.best_match(req,path).version, '1.4')
+
+        # If the first matching distro is unsuitable, it's a version conflict
+        path.insert(0,"FooPkg-1.2-py2.4.egg")
+        self.assertRaises(VersionConflict, ad.best_match, req, path)        
+
+        # If more than one match on the path, the first one takes precedence
+        path.insert(0,"FooPkg-1.4-py2.4-win32.egg")
+        self.assertEqual(ad.best_match(req,path).version, '1.4')
+        
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
     def checkFooPkg(self,d):
         self.assertEqual(d.name, "FooPkg")
         self.assertEqual(d.key, "foopkg")
@@ -83,7 +124,7 @@ class DistroTests(TestCase):
 class RequirementsTests(TestCase):
 
     def testBasics(self):
-        r = Requirement("Twisted", [('>=','1.2')])
+        r = Requirement.parse("Twisted>=1.2")
         self.assertEqual(str(r),"Twisted>=1.2")
         self.assertEqual(repr(r),"Requirement('Twisted', [('>=', '1.2')])")
         self.assertEqual(r, Requirement("Twisted", [('>=','1.2')]))
@@ -142,15 +183,15 @@ class ParseTests(TestCase):
             list(parse_requirements('Twisted >=1.2, \ # more\n<2.0')),
             [Requirement('Twisted',[('>=','1.2'),('<','2.0')])]
         )
-        self.assertRaises(ValueError,lambda:list(parse_requirements(">=2.3")))
-        self.assertRaises(ValueError,lambda:list(parse_requirements("x\\")))
-        self.assertRaises(ValueError,lambda:list(parse_requirements("x==2 q")))
-
-
-
-
-
-
+        self.assertEqual(
+            Requirement.parse("FooBar==1.99a3"),
+            Requirement("FooBar", [('==','1.99a3')])
+        )
+        self.assertRaises(ValueError,Requirement.parse,">=2.3")
+        self.assertRaises(ValueError,Requirement.parse,"x\\")
+        self.assertRaises(ValueError,Requirement.parse,"x==2 q")
+        self.assertRaises(ValueError,Requirement.parse,"X==1\nY==2")
+        self.assertRaises(ValueError,Requirement.parse,"#")