added mermaid and a lot of cmap changes

test/cmap-submap-navigation.test.js

@@ -0,0 +1,74 @@
+"use strict";
+
+const test = require("node:test");
+const assert = require("node:assert/strict");
+
+function fakeNode(attributes) {
+  const state = { ...attributes };
+  return {
+    attr(value) {
+      if (typeof value === "string") return state[value];
+      Object.assign(state, value);
+      return this;
+    },
+    onRendered() {}, onMove() {}, onMoveEnd() {}, visible() {}, redraw() {},
+    toFront() {}, remove() {}, element: () => null
+  };
+}
+
+function loadEditorFactory() {
+  global.Element = class Element {};
+  global.document = {
+    currentScript: null,
+    styleSheets: [],
+    body: { append() {} },
+    createElement: () => ({ style: {}, remove() {} })
+  };
+  global.window = {
+    Cmap: null,
+    setTimeout,
+    clearTimeout,
+    requestAnimationFrame: (callback) => callback()
+  };
+  require("../static/cmap/cmap-racket-wiki.js");
+  return global.window.RacketWikiCmap;
+}
+
+test("back from a second nested submap returns exactly one map level", () => {
+  const factory = loadEditorFactory();
+  const map = {
+    onSelection() {},
+    onActivation() {},
+    node: (attributes) => fakeNode(attributes)
+  };
+  const canvas = {
+    addEventListener() {}, querySelector: () => null,
+    clientWidth: 1200, clientHeight: 800, scrollLeft: 0, scrollTop: 0,
+    isConnected: true
+  };
+  const editor = factory.createEditor(canvas, { Cmap: () => map });
+  const first = editor.addItem({
+    id: 1, kind: "submap", label: "First level", separateMap: true,
+    mapReference: { id: "first", title: "First level" },
+    x: 100, y: 100, width: 220, height: 70
+  });
+  first.submapInitialized = true;
+  const second = editor.addItem({
+    id: 2, kind: "submap", label: "Second level", separateMap: true,
+    mapReference: { id: "second", title: "Second level" },
+    parentSubmap: first, submapDepth: 1,
+    x: 400, y: 200, width: 220, height: 70
+  });
+  second.submapInitialized = true;
+
+  editor.openSubmapMap(first);
+  editor.openSubmapMap(second);
+  assert.equal(editor.activeMapRoot, second);
+  assert.equal(editor.canStepBackWithinMap(), true,
+    "the host must use local map history before navigating to a source CMap route");
+
+  editor.openParentMap();
+
+  assert.equal(editor.activeMapRoot, first);
+  assert.equal(editor.canStepBackWithinMap(), false);
+});