test(colorbar): guard stackOrientation round-trip in project state

Export normalizeColorbarState and add unit tests that a horizontal stack
choice persists, missing/unknown values fall back to vertical, and the
state round-trips cleanly. Addresses review feedback on PR #901.

Author: giswqs

packages/plugins/src/plugins/maplibre-components.ts

@@ -1432,7 +1432,7 @@ function normalizeComponentsProjectState(
   };
 }
 
-function normalizeColorbarState(
+export function normalizeColorbarState(
   state: unknown
 ): ComponentColorbarGuiState | undefined {
   if (!state || typeof state !== "object") return undefined;

tests/colorbar-state-normalization.test.ts

@@ -0,0 +1,58 @@
+import assert from "node:assert/strict";
+import { describe, it } from "node:test";
+import { normalizeColorbarState } from "../packages/plugins/src/plugins/maplibre-components.ts";
+
+/**
+ * The colorbar plugin persists a `stackOrientation` flag (vertical vs
+ * horizontal stacking) in the saved project state. These tests guard the
+ * normalization path that runs on both live control snapshots and deserialized
+ * project JSON, so a user's horizontal choice round-trips on reopen and old
+ * projects without the field fall back to the previous (vertical) behavior.
+ */
+describe("normalizeColorbarState stackOrientation", () => {
+  it("keeps a horizontal stack orientation", () => {
+    const normalized = normalizeColorbarState({
+      visible: true,
+      colorbars: [],
+      stackOrientation: "horizontal",
+    });
+    assert.equal(normalized?.stackOrientation, "horizontal");
+  });
+
+  it("defaults missing stack orientation to vertical (backward compat)", () => {
+    const normalized = normalizeColorbarState({ visible: true, colorbars: [] });
+    assert.equal(normalized?.stackOrientation, "vertical");
+  });
+
+  it("coerces an unknown stack orientation to vertical", () => {
+    const normalized = normalizeColorbarState({
+      visible: true,
+      colorbars: [],
+      stackOrientation: "diagonal",
+    });
+    assert.equal(normalized?.stackOrientation, "vertical");
+  });
+
+  it("round-trips a horizontal choice through a second normalization", () => {
+    const once = normalizeColorbarState({
+      visible: true,
+      colorbars: [
+        {
+          mode: "named",
+          colormap: "viridis",
+          customColors: "",
+          vmin: 0,
+          vmax: 100,
+          label: "Depth",
+          units: "",
+          orientation: "vertical",
+          colorbarPosition: "bottom-right",
+        },
+      ],
+      stackOrientation: "horizontal",
+    });
+    const twice = normalizeColorbarState(once);
+    assert.equal(twice?.stackOrientation, "horizontal");
+    assert.deepEqual(twice, once);
+  });
+});