fix(map): preserve empty facet selection

scripts/map-presentation-filters.test.mjs

@@ -49,13 +49,53 @@ test("deselecting the last chip remains empty and never normalizes to all", () =
   assert.equal(mapFactMatchesFilters(onlineMoving, profile, filters, "fleet"), false);
 });
 
-test("interactive deselect of the last chip removes the facet constraint", () => {
+test("interactive deselect of the last chip preserves the zero-match state", () => {
   const selected = toggleMapPresentationFacetSelection({}, "signal_state", "active");
   assert.deepEqual(selected, { signal_state: ["active"] });
 
-  const unconstrained = toggleMapPresentationFacetSelection(selected, "signal_state", "active");
-  assert.deepEqual(unconstrained, {});
-  assert.equal(mapPresentationBindingIsAll("fleet", { fleet: { visible: true, facets: unconstrained } }), true);
+  const empty = toggleMapPresentationFacetSelection(selected, "signal_state", "active");
+  const filters = { fleet: { visible: true, facets: empty } };
+  assert.deepEqual(empty, { signal_state: [] });
+  assert.equal(mapPresentationBindingIsAll("fleet", filters), false);
+  assert.equal(mapFactMatchesFilters(onlineMoving, profile, filters, "fleet"), false);
+});
+
+test("the first chip selected after a saved empty view removes every empty sentinel", () => {
+  const selected = toggleMapPresentationFacetSelection({
+    signal_state: [],
+    movement_state: [],
+  }, "signal_state", "active");
+
+  assert.deepEqual(selected, { signal_state: ["active"] });
+  assert.equal(mapFactMatchesFilters(onlineMoving, profile, {
+    fleet: { visible: true, facets: selected },
+  }, "fleet"), true);
+});
+
+test("a complete interactive toggle cycle returns to zero matches instead of all", () => {
+  let facets = { signal_state: [], movement_state: [] };
+  const toggle = (field, value) => {
+    facets = toggleMapPresentationFacetSelection(facets, field, value);
+  };
+
+  toggle("signal_state", "active");
+  toggle("signal_state", "inactive");
+  toggle("movement_state", "moving");
+  toggle("movement_state", "stopped");
+  assert.deepEqual(facets, {
+    signal_state: ["active", "inactive"],
+    movement_state: ["moving", "stopped"],
+  });
+
+  toggle("signal_state", "active");
+  toggle("signal_state", "inactive");
+  toggle("movement_state", "moving");
+  toggle("movement_state", "stopped");
+
+  const filters = { fleet: { visible: true, facets } };
+  assert.deepEqual(facets, { movement_state: [] });
+  assert.equal(mapPresentationBindingIsAll("fleet", filters), false);
+  assert.equal(mapFactMatchesFilters(onlineMoving, profile, filters, "fleet"), false);
 });
 
 test("interactive deselect preserves other values and facet constraints", () => {