Fix legacy build

The build process failed because webpack does not allow failed imports
when it is run as a module.
This detects modules with default exports and only generates import
statements for default exports where they are available.

config/jsdoc/plugins/events.cjs

@@ -0,0 +1,39 @@
+/* eslint-disable import/no-commonjs */
+
+const events = {};
+
+exports.handlers = {
+  newDoclet: function (e) {
+    const doclet = e.doclet;
+    if (doclet.kind !== 'event') {
+      return;
+    }
+
+    const cls = doclet.longname.split('#')[0];
+    if (!(cls in events)) {
+      events[cls] = [];
+    }
+    events[cls].push(doclet.longname);
+  },
+
+  parseComplete: function (e) {
+    const doclets = e.doclets;
+    for (let i = 0, ii = doclets.length - 1; i < ii; ++i) {
+      const doclet = doclets[i];
+      if (doclet.fires) {
+        if (doclet.kind == 'class') {
+          const fires = [];
+          for (let j = 0, jj = doclet.fires.length; j < jj; ++j) {
+            const event = doclet.fires[j].replace('event:', '');
+            if (events[event]) {
+              fires.push.apply(fires, events[event]);
+            } else if (doclet.fires[j] !== 'event:ObjectEvent') {
+              fires.push(doclet.fires[j]);
+            }
+          }
+          doclet.fires = fires;
+        }
+      }
+    }
+  },
+};