Test every behaviour the review named

A 1-D navigator drag lands on its time frame and a span gathers the run
between its edges; a figure's own marker group survives a dispatch; a
mismatched ragged index and a short reduce mask both throw; a views button
re-reads the frame from its block; a reduce binding with no detector is
refused at mount while a crosshair on that panel is ignored at dispatch; a
circle detector gives the navigator numpy's einsum; a geom push leaves a live
binary token alone but yields to one of its own; two figures in one document
keep their own pixels; the frame window stays the panel's; and a resize does
not reach the panel before the bytes it describes.

The region mean is compared with a tolerance of one code, since a float32 sum
scaled by 1/n and numpy's float64 mean can truncate either side of a
boundary, and the rasterDisks reference states the convention (a filled disk
per row, combined by max or sum) rather than transcribing the loop.

Author: CSSFrancis

anyplotlib/tests/test_embed/test_embed_api.py

@@ -227,3 +227,43 @@ def test_state_dict_is_accepted_in_place_of_a_figure(self):
                               {"cube": np.zeros((4, 4, 8, 8), dtype=np.uint8)},
                               self._bindings(navigator, signal))
         assert f"panel_{signal._id}_json" in html
+
+
+class TestEmbedSurface:
+    def test_the_readers_live_under_one_namespace(self):
+        """Generic names stay out of the top level beside mount / render."""
+        source = esm_path().read_text(encoding="utf-8")
+        assert "export const embed = {" in source
+        assert "export async function mountNavigated" in source
+        for name in ("dense", "ragged", "toU8", "decodeBlocks",
+                     "maskFromWidget", "rasterDisks", "robustLevels"):
+            assert f"export function {name}(" not in source, (
+                f"{name} is still a top-level export")
+            assert f"export async function {name}(" not in source
+
+    def test_views_blocks_are_validated(self):
+        fig, axes = apl.subplots(1, 2, figsize=(400, 200))
+        navigator = axes[0].imshow(np.zeros((4, 4), dtype=np.uint8))
+        panel = axes[1].imshow(np.zeros((8, 8), dtype=np.uint8))
+        cube = np.zeros((4, 4, 8, 8), dtype=np.uint8)
+        bindings = [
+            {"panel_id": navigator._id, "role": "navigator"},
+            {"panel_id": panel._id, "role": "driven",
+             "views": [{"label": "a", "block": "cube"},
+                       {"label": "b", "block": "gone"}]},
+        ]
+        with pytest.raises(ValueError, match="unknown block 'gone'"):
+            navigated_html(fig, {"cube": cube}, bindings)
+
+    def test_a_views_binding_needs_no_frame_block(self):
+        fig, axes = apl.subplots(1, 2, figsize=(400, 200))
+        navigator = axes[0].imshow(np.zeros((4, 4), dtype=np.uint8))
+        panel = axes[1].imshow(np.zeros((8, 8), dtype=np.uint8))
+        cube = np.zeros((4, 4, 8, 8), dtype=np.uint8)
+        html = navigated_html(
+            fig, {"cube": cube},
+            [{"panel_id": navigator._id, "role": "navigator"},
+             {"panel_id": panel._id, "role": "driven",
+              "views": [{"label": "a", "block": "cube"}],
+              "frame": {"kind": "image"}}])
+        assert f'id="apl-views-{panel._id}"' in html