refactor(core): CORE-02 type emitter maps and fix nested once dispatch

test/browser/emitter.spec.js

@@ -0,0 +1,28 @@
+import { expect, test } from './fixtures.js'
+
+for (const core of ['published', 'candidate']) {
+  test(`${core}: emitter event names and once across nested dispatch`, async ({ page }) => {
+    await page.goto(`/test/player.html?core=${core}&chapter=published`)
+    const result = await page.evaluate(() => {
+      const emitter = new window.Artplayer.Emitter()
+      const freshKeys = Object.keys(emitter)
+      let reservedCalls = 0
+      let errorName
+      try {
+        emitter.on('__proto__', () => reservedCalls++).emit('__proto__').off('__proto__')
+      }
+      catch (error) { errorName = error.name }
+      let nested = false
+      let onceCalls = 0
+      emitter.on('value', () => {
+        if (!nested) {
+          nested = true
+          emitter.emit('value')
+        }
+      }).once('value', () => onceCalls++)
+      emitter.emit('value')
+      return { freshKeys, reservedCalls, errorName, onceCalls }
+    })
+    expect(result).toEqual({ freshKeys: [], reservedCalls: core === 'published' ? 0 : 1, errorName: core === 'published' ? 'TypeError' : undefined, onceCalls: core === 'published' ? 2 : 1 })
+  })
+}