Fixes #45.

The discover function now no longer traverses directories when it's
passed the specified `depth` or `treantdepth` parameters. Added proper
tests to make sure these parameters function as expected.

CHANGELOG

@@ -33,6 +33,8 @@ Fixes
       automatically get all limbs of the object they were obtained from;
       set operations between Views/Bundles will give unions of their attached
       limbs
+    * ``datreant.core.discover`` no longer traverses directories beyond given
+      depth, or beyond treantdepth. These parameters now work as expected. #45
 
 
 Changes

src/datreant/core/manipulators.py

@@ -5,6 +5,7 @@
 import os
 import scandir
 import fnmatch
+from six.moves import range
 
 from . import _TREANTS
 
@@ -45,30 +46,35 @@ def discover(dirpath='.', depth=None, treantdepth=None):
     treantdirs = set()
 
     for root, dirs, files in scandir.walk(dirpath):
-        # depth check; if too deep, next iteration
-        if depth and len(root.split(os.sep)) - startdepth > depth:
+        for treanttype in _TREANTS:
+            outnames = fnmatch.filter(files,
+                                      "{}.*.json".format(treanttype))
+
+            if treantdepth is not None and outnames:
+                treantdirs.add(root)
+
+            paths = [os.path.join(root, file) for file in outnames]
+            found.extend(paths)
+
+        # depth check; if too deep, empty dirs to avoid downward traversal
+        if depth is not None and len(root.split(os.sep)) - startdepth >= depth:
+            for i in range(len(dirs)):
+                dirs.pop()
             continue
 
         # Treant depth checking
-        if treantdepth:
+        if treantdepth is not None:
 
             # remove Treant dirs from our set of them if we've backed out
             for treantdir in list(treantdirs):
                 if treantdir not in root:
                     treantdirs.remove(treantdir)
 
-            # actual depth check
+            # actual depth check; if too deep, empty dirs to avoid downward
+            # traversal
             if len(treantdirs) > treantdepth:
+                for i in range(len(dirs)):
+                    dirs.pop()
                 continue
 
-        for treanttype in _TREANTS:
-            outnames = fnmatch.filter(files,
-                                      "{}.*.json".format(treanttype))
-
-            if treantdepth and outnames:
-                treantdirs.add(root)
-
-            paths = [os.path.join(root, file) for file in outnames]
-            found.extend(paths)
-
     return Bundle(found)

src/datreant/core/tests/test_manipulators.py

@@ -24,3 +24,75 @@ def test_discover(tmpdir):
 
         for name in ghosts:
             assert name in b.names
+
+
+def test_discover_depth(tmpdir):
+    """Check that using `depth` parameter gives expected result."""
+    with tmpdir.as_cwd():
+
+        ghosts = ('something/inky',
+                  'something/else/blinky',
+                  'pinky',
+                  'something/clyde')
+
+        for name in ghosts:
+            dtr.Treant(name)
+
+        assert len(discover('.', depth=0)) == 0
+        assert len(discover('pinky', depth=0)) == 1
+
+        assert len(discover('.', depth=1)) == 1
+        assert len(discover('.', depth=2)) == 3
+        assert len(discover('.', depth=3)) == 4
+
+
+def test_discover_treantdepth(tmpdir):
+    """Check that using `treantdepth` parameter gives expected result."""
+    with tmpdir.as_cwd():
+
+        ghosts = ('inky',
+                  'inky/blinky',
+                  'pinky',
+                  'inky/blinky/clyde')
+
+        for name in ghosts:
+            dtr.Treant(name)
+
+        assert len(discover('.', treantdepth=0)) == 2
+        assert len(discover('pinky', treantdepth=0)) == 1
+        assert len(discover('inky', treantdepth=0)) == 1
+
+        assert len(discover('.', treantdepth=1)) == 3
+        assert len(discover('.', treantdepth=2)) == 4
+        assert len(discover('inky', treantdepth=1)) == 2
+        assert len(discover('inky/blinky', treantdepth=1)) == 2
+
+        assert len(discover('inky/blinky', treantdepth=1)) == 2
+
+
+def test_discover_depth_treantdepth(tmpdir):
+    """Check that using `treantdepth` and `depth` parameters together gives
+        expected result.
+    """
+    with tmpdir.as_cwd():
+
+        ghosts = ('inky',
+                  'inky/blinky',
+                  'pinky',
+                  'inky/blinky/nothing/clyde')
+
+        for name in ghosts:
+            dtr.Treant(name)
+
+        assert len(discover('.', treantdepth=0, depth=0)) == 0
+        assert len(discover('.', treantdepth=0, depth=1)) == 2
+        assert len(discover('pinky', treantdepth=0, depth=0)) == 1
+        assert len(discover('inky', treantdepth=0, depth=2)) == 1
+
+        assert len(discover('.', treantdepth=1, depth=1)) == 2
+        assert len(discover('inky', treantdepth=1, depth=1)) == 2
+        assert len(discover('inky', treantdepth=1, depth=0)) == 1
+
+        assert len(discover('inky', treantdepth=2)) == 3
+        assert len(discover('inky', treantdepth=2, depth=2)) == 2
+        assert len(discover('inky', treantdepth=2, depth=3)) == 3