tests: Expand testing for Border, refactor, and bugfix

Author: EdCaunt

devito/types/grid.py

@@ -1071,7 +1071,7 @@ def _parse_border(border: BorderSpec, grid: Grid) -> ParsedBorderSpec:
             if not len(border) == len(grid.dimensions):
                 raise ValueError("Length of border thickness specification should "
                                  "match number of dimensions")
-            retval = []  # FIXME: make a better name later
+            retval = []
             for b, d in zip(border, grid.dimensions):
                 if isinstance(b, tuple):
                     if not len(b) == 2:
@@ -1157,22 +1157,17 @@ def _build_domains_nooverlap(self, grid: Grid) -> tuple[int, tuple[np.ndarray]]:
                 domain_map[d] = (CENTER,)
                 interval_map[d] = {CENTER: (0, 0)}
 
-        # Get the cartesian product, then remove any which solely consist of
-        # the central region. The sides are used to make this step more
-        # straightforward.
-        abstract_domains = list(product(*domain_map.values()))
-        for d in abstract_domains:
-            if all(i == CENTER for i in d):
-                abstract_domains.remove(d)
-
-            # If 'no corners' option selected, then remove any corners
-            if self.corners == 'nocorners' and not any(i == CENTER for i in d):
-                abstract_domains.remove(d)
-
+        # Get the cartesian product, then select the required domains. The sides are used
+        # to make this step more straightforward.
+        maybe_domains = list(product(*domain_map.values()))
         domains = []
-        for dom in abstract_domains:
-            domains.append([interval_map[d][i]
-                            for d, i in zip(grid.dimensions, dom)])
+        for d in maybe_domains:
+            if not all(i == CENTER for i in d):
+                # Don't add any domains that are completely centered
+                if self.corners != 'nocorners' or any(i == CENTER for i in d):
+                    # Don't add corners if 'no corners' option selected
+                    domains.append([interval_map[dim][dom] for (dim, dom)
+                                    in zip(grid.dimensions, d)])
 
         domains = np.array(domains)
 

tests/test_subdomains.py

@@ -726,11 +726,78 @@ class Dummy(SubDomainSet):
 
 
 class TestBorder:
+    def test_exceptions(self):
+        """Test exceptions are raised for malformed specifications"""
+        grid = Grid(shape=(5,))
+
+        with pytest.raises(ValueError):
+            _ = Border(grid, (1, 1))
+
+        with pytest.raises(ValueError):
+            _ = Border(grid, ((1, 1, 1),))
+
+    @pytest.mark.parametrize('corners', ['nooverlap', 'overlap', 'nocorners'])
+    def test_uneven_border(self, corners):
+        """Test border specifications which vary by dimension"""
+        shape = (6, 8)
+        grid = Grid(shape=shape)
+        x, y = grid.dimensions
+
+        border = Border(grid, (1, (2, 1)), corners=corners)
+
+        f = Function(name='f', grid=grid, dtype=np.int32)
+
+        eq = Eq(f, f+1, subdomain=border)
+
+        Operator(eq)()
+
+        check = np.ones(shape)
+        check[1:-1, 2:-1] = 0
+
+        if corners == 'nocorners':
+            check[0, :2] = 0
+            check[-1, :2] = 0
+            check[0, -1] = 0
+            check[-1, -1] = 0
+        elif corners == 'overlap':
+            check[0, :2] = 2
+            check[-1, :2] = 2
+            check[0, -1] = 2
+            check[-1, -1] = 2
+
+        assert np.all(f.data == check)
+
+    @pytest.mark.parametrize('corners', ['nooverlap', 'overlap', 'nocorners'])
+    def test_one_sided_border(self, corners):
+        """Test borders where a particular side is specified"""
+        shape = (6, 8)
+        grid = Grid(shape=shape)
+        x, y = grid.dimensions
+
+        # border = Border(grid, 2, dims={x: x, y: 'right'})
+        border = Border(grid, 1, dims={x: 'left', y: 'right'}, corners=corners)
+
+        f = Function(name='f', grid=grid, dtype=np.int32)
+
+        eq = Eq(f, f+1, subdomain=border)
+
+        Operator(eq)()
+
+        check = np.zeros(shape)
+        check[0, :] = 1
+        check[:, -1] = 1
+
+        if corners == 'overlap':
+            check[0, -1] = 2
+        elif corners == 'nocorners':
+            check[0, 0] = 0
+            check[0, -1] = 0
+            check[-1, -1] = 0
+
+        assert np.all(f.data == check)
+
     def test_border_3d(self):
-        """
-        Test the functionality of the Border class in higher dimensions.
-        Note that this class is also covered by doctests and examples.
-        """
+        """Test the functionality of the Border class in higher dimensions"""
         grid = Grid(shape=(3, 3, 3))
 
         border = Border(grid, 1)