copy first keyframe button

test/block-requirements.test.js

@@ -48,6 +48,8 @@ function harness() {
   const context = {
     Project: project, Group, Cube, Plugin: { register(id, definition) { context.registration = definition; } },
     Action: class { constructor(id, options) { Object.assign(this, options, { id }); } },
+    Toggle: class { constructor(id, options) { Object.assign(this, options, { id, value: false }); } },
+    Timeline: { loop() {} },
     Panel: class {
       constructor(id, options) {
         this.options = options;

test/stage-autoplay.test.js

@@ -0,0 +1,50 @@
+const test = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+const vm = require('node:vm');
+
+function harness() {
+  const h = { Plugin: { register() {} }, Animation: { selected: null, all: [] }, Format: { id: 'geckolib_model' },
+    Animator: { preview() { h.rendered = h.Animation.selected; } },
+    Timeline: { playing: true, custom_range: [0, 0], loop() { this.playing = false; }, setTime(time) { this.time = time; }, start() { this.playing = true; this.loop(); } } };
+  const source = fs.readFileSync(path.join(__dirname, '..', 'AnimationDirector.js'), 'utf8').replace('  Plugin.register(PLUGIN_ID, {',
+    '  globalThis.api = { installStageAutoplay, removeStageAutoplay, nextAutoplayStage, setEnabled(value) { autoplayStagesAction = { value }; } };\n  Plugin.register(PLUGIN_ID, {');
+  vm.runInNewContext(source, h);
+  h.clip = (name, loop = 'once') => ({ name, length: 2, loop, select() { h.Animation.selected = this; } });
+  h.api.setEnabled(true); h.api.installStageAutoplay();
+  return h;
+}
+
+test('autoplay advances completed non-looping stages by number within the same ID', () => {
+  const h = harness(), first = h.clip('example.p1'), next = h.clip('example.p2');
+  h.Animation.selected = first; h.Animation.all = [h.clip('other.p2'), h.clip('example.p10'), next, first];
+  h.Timeline.loop();
+  assert.equal(h.Animation.selected, next);
+  assert.equal(h.Timeline.time, 0);
+  assert.equal(h.Timeline.playing, true);
+  assert.equal(h.rendered, next);
+});
+
+test('autoplay leaves looping stages, custom ranges, disabled toggle and final stage alone', () => {
+  for (const mode of ['loop', 'range', 'disabled', 'final']) {
+    const h = harness(), first = h.clip('example.p1', mode === 'loop' ? 'loop' : 'hold');
+    h.Animation.selected = first; h.Animation.all = mode === 'final' ? [first] : [first, h.clip('example.p2')];
+    if (mode === 'range') h.Timeline.custom_range = [0, 1];
+    if (mode === 'disabled') h.api.setEnabled(false);
+    h.Timeline.loop();
+    assert.equal(h.pending, undefined);
+    assert.equal(h.Animation.selected, first);
+  }
+});
+
+test('manual playback stops do not advance and unload restores playback', () => {
+  const h = harness(), first = h.clip('example.p1'), next = h.clip('example.p2');
+  h.Animation.selected = first; h.Animation.all = [first, next];
+  h.Timeline.playing = false; h.Timeline.loop();
+  assert.equal(h.pending, undefined);
+  assert.equal(h.Animation.selected, first);
+  assert.equal(h.Timeline.playing, false);
+  const wrapper = h.Timeline.loop; h.api.removeStageAutoplay();
+  assert.notEqual(h.Timeline.loop, wrapper);
+});