viz: fix ellipsis n_requested count; add 2-rank ghost-cell assembly fixture

Author: sbryngelson

toolchain/mfc/viz/fixtures/1d_binary_2rank/binary/p0/0.dat

@@ -21,6 +21,7 @@
 FIX_2D_SILO = os.path.join(FIXTURES, '2d_silo')
 FIX_3D_BIN = os.path.join(FIXTURES, '3d_binary')
 FIX_3D_SILO = os.path.join(FIXTURES, '3d_silo')
+FIX_1D_BIN_2RANK = os.path.join(FIXTURES, '1d_binary_2rank')
 
 
 # ---------------------------------------------------------------------------
@@ -104,6 +105,14 @@ def test_ellipsis_must_be_second_to_last(self):
         with self.assertRaises(MFCException):
             self._parse('0,100,...,500,1000', [0, 100, 500, 1000])
 
+    def test_ellipsis_n_requested_is_expanded_range(self):
+        """Ellipsis n_requested reflects the expanded range, not the matched count."""
+        from .viz import _parse_steps
+        # Range 0,100,...,1000 expands to 11 steps; only 3 are available.
+        matched, n_req = _parse_steps('0,100,...,1000', [0, 200, 1000])
+        self.assertEqual(n_req, 11)
+        self.assertEqual(matched, [0, 200, 1000])
+
     def test_invalid_value(self):
         """Non-numeric, non-keyword input raises MFCException."""
         from mfc.common import MFCException
@@ -230,6 +239,44 @@ def test_var_filter(self):
         self.assertNotIn('vel1', data.variables)
 
 
+class TestAssembleBinary1DMultiRank(unittest.TestCase):
+    """Test multi-rank assembly with overlapping ghost cells (1D, 2 ranks)."""
+
+    def test_ndim(self):
+        """2-rank 1D fixture assembles with ndim=1."""
+        from .reader import assemble
+        data = assemble(FIX_1D_BIN_2RANK, 0, 'binary')
+        self.assertEqual(data.ndim, 1)
+
+    def test_cell_count_after_dedup(self):
+        """Ghost cell overlap is deduplicated: 16 unique cells from two overlapping ranks."""
+        from .reader import assemble
+        data = assemble(FIX_1D_BIN_2RANK, 0, 'binary')
+        self.assertEqual(len(data.x_cc), 16)
+
+    def test_grid_is_sorted_and_unique(self):
+        """Assembled global grid is strictly increasing with no duplicates."""
+        import numpy as np
+        from .reader import assemble
+        data = assemble(FIX_1D_BIN_2RANK, 0, 'binary')
+        diffs = np.diff(data.x_cc)
+        self.assertTrue(bool(np.all(diffs > 0)), "x_cc is not strictly increasing")
+
+    def test_variable_values_match_position(self):
+        """pres values (== x_cc position) are placed at the correct global cells."""
+        import numpy as np
+        from .reader import assemble
+        data = assemble(FIX_1D_BIN_2RANK, 0, 'binary')
+        np.testing.assert_allclose(data.variables['pres'], data.x_cc, atol=1e-10)
+
+    def test_all_vars_present(self):
+        """Both variables written by both ranks appear in the assembled output."""
+        from .reader import assemble
+        data = assemble(FIX_1D_BIN_2RANK, 0, 'binary')
+        self.assertIn('pres', data.variables)
+        self.assertIn('rho', data.variables)
+
+
 class TestAssembleBinary2D(unittest.TestCase):
     """Test binary reader with 2D fixture data."""
 

toolchain/mfc/viz/fixtures/1d_binary_2rank/binary/p1/0.dat

@@ -168,8 +168,15 @@ def _parse_steps(step_arg, available_steps):
         # n_requested: count of explicit values (ellipsis form expands to a range)
         parts = [p.strip() for p in s.split(',')]
         if '...' in parts:
-            # approximate from the parsed result + unmatched
-            n_req = len(matched)  # conservative; exact count needs re-parsing
+            # Compute the expanded range length independently of filtering.
+            try:
+                idx = parts.index('...')
+                prefix = [int(p) for p in parts[:idx]]
+                end_val = int(parts[-1])
+                stride = prefix[-1] - prefix[-2]
+                n_req = len(range(prefix[0], end_val + 1, stride)) if stride > 0 else len(matched)
+            except (ValueError, IndexError):
+                n_req = len(matched)
         else:
             n_req = len(parts)
         return matched, n_req