Add reorderSound and unit test to rendered-target

src/sprites/rendered-target.js

@@ -662,6 +662,24 @@ class RenderedTarget extends Target {
         this.setCostume(this.getCostumeIndexByName(currentCostume.name));
     }
 
+    /**
+     * Reorder sound list by moving sound at soundIndex to newIndex.
+     * @param {!number} soundIndex Index of the sound to move.
+     * @param {!number} newIndex New index for that sound.
+     */
+    reorderSound (soundIndex, newIndex) {
+        const clampedNewIndex =
+            Math.max(0, Math.min(this.sprite.sounds.length - 1, newIndex));
+        const clampedSoundIndex =
+            Math.max(0, Math.min(this.sprite.sounds.length - 1, soundIndex));
+
+        if (clampedNewIndex === clampedSoundIndex) return;
+
+        const sound = this.sprite.sounds[clampedSoundIndex];
+        this.deleteSound(clampedSoundIndex);
+        this.addSound(sound, clampedNewIndex);
+    }
+
     /**
      * Get full sound list
      * @return {object[]} list of sounds

test/unit/sprites_rendered-target.js

@@ -476,3 +476,45 @@ test('#reorderCostume', t => {
 
     t.end();
 });
+
+test('#reorderSound', t => {
+    const o1 = {id: 0, name: 'name0'};
+    const o2 = {id: 1, name: 'name1'};
+    const o3 = {id: 2, name: 'name2'};
+    const o4 = {id: 3, name: 'name3'};
+    const o5 = {id: 4, name: 'name4'};
+    const s = new Sprite();
+    const r = new Runtime();
+    s.sounds = [o1, o2, o3, o4, o5];
+    const a = new RenderedTarget(s, r);
+    const renderer = new FakeRenderer();
+    a.renderer = renderer;
+
+    const resetSounds = () => {
+        s.sounds = [o1, o2, o3, o4, o5];
+    };
+    const soundIds = () => a.sprite.sounds.map(c => c.id);
+
+    resetSounds();
+    t.deepEquals(soundIds(), [0, 1, 2, 3, 4]);
+
+    // Make sure reordering up and down works and current sound follows
+    resetSounds();
+    a.reorderSound(0, 3);
+    t.deepEquals(soundIds(), [1, 2, 3, 0, 4]);
+
+    resetSounds();
+    a.reorderSound(3, 1);
+    t.deepEquals(soundIds(), [0, 3, 1, 2, 4]);
+
+    // Out of bounds indices get clamped
+    resetSounds();
+    a.reorderSound(10, 0);
+    t.deepEquals(soundIds(), [4, 0, 1, 2, 3]);
+
+    resetSounds();
+    a.reorderSound(2, -1000);
+    t.deepEquals(soundIds(), [2, 0, 1, 3, 4]);
+
+    t.end();
+});