@facebook/test-audio

---
name: test-audio
description: 'Test audio system (AudioSource loading, playback state, stop, spatial audio) against the audio example using mcp-call.mjs WebSocket CLI.'
argument-hint: '[--suite loading|playback|stop|all]'
---

# Audio System Test

Run 6 test suites covering audio loading, playback trigger, stop, system registration, component schema, and stability.

All tool calls go through `scripts/mcp-call.mjs` via WebSocket — no MCP server, no permission prompts.

**Configuration:**

- EXAMPLE_DIR: /Users/felixz/Projects/immersive-web-sdk/examples/audio
- ROOT: /Users/felixz/Projects/immersive-web-sdk

**SHORTHAND**: Throughout this document, `MCPCALL` means:

```
node /Users/felixz/Projects/immersive-web-sdk/scripts/mcp-call.mjs --port <PORT>
```

where `<PORT>` is the port number discovered in Step 2.

**Tool calling pattern**: Every tool call is a Bash command using the MCPCALL shorthand:

```
MCPCALL --tool <TOOL_NAME> --args '<JSON_ARGS>' 2>/dev/null
```

- `<TOOL_NAME>` uses MCP-style names (e.g. `browser_reload_page`, `xr_accept_session`). The script handles translation internally.
- `<JSON_ARGS>` is a JSON object string. Omit `--args` if no arguments needed.
- Output is JSON on stdout. Parse it to check assertions.
- Use `--timeout 20000` for operations that may take longer (reload, accept_session, screenshot).
- Always append `2>/dev/null` to suppress TLS warnings.

**IMPORTANT**: Run each Bash command one at a time. Parse the JSON output and verify assertions before moving to the next command. Do NOT chain multiple mcp-call commands together.

**IMPORTANT**: When the instructions say "wait N seconds", use `sleep N` as a separate Bash command.

**IMPORTANT**: Boolean values in `ecs_set_component` must be actual JSON booleans (`value: true`), NOT strings (`value: "true"`). Strings silently fail to coerce.

---

## Step 1: Install Dependencies

```bash
cd /Users/felixz/Projects/immersive-web-sdk/examples/audio && npm run fresh:install
```

Wait for this to complete before proceeding.

---

## Step 2: Start Dev Server

Start the dev server as a background task using the Bash tool's `run_in_background: true` parameter:

```bash
cd /Users/felixz/Projects/immersive-web-sdk/examples/audio && npm run dev
```

**IMPORTANT**: This command MUST be run with `run_in_background: true` on the Bash tool — do NOT append `&` to the command itself.

Once the background task is launched, poll the output for Vite's ready message (up to 60s). Read the task output or use `tail` to watch for a line containing `Local:`. The output will contain a URL like `https://localhost:5173/`. Extract the port number from this URL and save it as `<PORT>`. All subsequent `MCPCALL` commands use this port.

If the server fails to start within 60 seconds, report FAIL for all suites and skip to Step 5.

---

## Step 3: Verify Connectivity

```bash
MCPCALL --tool ecs_list_systems 2>/dev/null
```

This must return JSON with a list of systems. If it fails:

1. Check the dev server output for errors
2. Try killing and restarting the server (Step 2)
3. If it still fails, report FAIL for all suites and skip to Step 5

---

## Step 4: Run Test Suites

### Pre-test Setup

Run these commands in order:

1. `MCPCALL --tool browser_reload_page --timeout 20000 2>/dev/null`
   Then: `sleep 3`

2. `MCPCALL --tool xr_accept_session --timeout 20000 2>/dev/null`
   Then: `sleep 2`

3. `MCPCALL --tool browser_get_console_logs --args '{"count":20,"level":["error"]}' 2>/dev/null`
   Assert: No error-level logs. Audio autoplay warnings are acceptable.

---

### Suite 1: Audio Loading

**Test 1.1: Find Audio Entity**

```bash
MCPCALL --tool ecs_find_entities --args '{"withComponents":["AudioSource"]}' 2>/dev/null
```

Assert: At least 1 entity. Save the first as `<audio>`.

The audio example uses a GLXF level that creates entities via composition. The Spinner entity has an AudioSource.

**Test 1.2: Verify Loaded State**

```bash
MCPCALL --tool ecs_query_entity --args '{"entityIndex":<audio>,"components":["AudioSource"]}' 2>/dev/null
```

Assert:

- `src` contains an audio file path (e.g., `.mp3`)
- `_loaded` = `true` (buffer loaded)
- `_loading` = `false` (not currently loading)
- `_isPlaying` = `false` (not playing yet — unless autoplay is set)
- `volume` = `1`
- `positional` = `true`

**Test 1.3: Pool Created**
Assert: `_pool` exists with `available` array matching `maxInstances`.

---

### Suite 2: Playback Trigger

**Test 2.1: Request Play**

```bash
MCPCALL --tool ecs_set_component --args '{"entityIndex":<audio>,"componentId":"AudioSource","field":"_playRequested","value":true}' 2>/dev/null
```

Assert: `_playRequested` was consumed (response shows `newValue: false` — the AudioSystem processed it within the same frame).

**Test 2.2: Play with Loop for Observable State**

Set `loop: true` first, then request play:

```bash
MCPCALL --tool ecs_set_component --args '{"entityIndex":<audio>,"componentId":"AudioSource","field":"loop","value":true}' 2>/dev/null
```

```bash
MCPCALL --tool ecs_set_component --args '{"entityIndex":<audio>,"componentId":"AudioSource","field":"_playRequested","value":true}' 2>/dev/null
```

Then query:

```bash
MCPCALL --tool ecs_query_entity --args '{"entityIndex":<audio>,"components":["AudioSource"]}' 2>/dev/null
```

Assert: `_isPlaying` = `true` (looping sound keeps playing).

---

### Suite 3: Stop

**Test 3.1: Request Stop**

```bash
MCPCALL --tool ecs_set_component --args '{"entityIndex":<audio>,"componentId":"AudioSource","field":"_stopRequested","value":true}' 2>/dev/null
```

Assert: `_stopRequested` consumed, `_isPlaying` becomes `false`.

---

### Suite 4: System Registration

```bash
MCPCALL --tool ecs_list_systems 2>/dev/null
```

Assert:

- AudioSystem at priority 0
- Config keys: `enableDistanceCulling`, `cullingDistanceMultiplier`
- `audioEntities` >= 1

---

### Suite 5: Component Schema

```bash
MCPCALL --tool ecs_list_components 2>/dev/null
```

Assert AudioSource fields:

- Core: `src` (FilePath), `volume` (Float32), `loop` (Boolean), `autoplay` (Boolean)
- Spatial: `positional` (Boolean), `refDistance`, `rolloffFactor`, `maxDistance`, `distanceModel`, `coneInnerAngle`, `coneOuterAngle`, `coneOuterGain`
- Behavior: `playbackMode` (Enum), `maxInstances` (Int8), `crossfadeDuration` (Float32), `instanceStealPolicy` (Enum)
- Control: `_playRequested`, `_pauseRequested`, `_stopRequested` (Boolean), `_fadeIn`, `_fadeOut` (Float32)
- State: `_pool` (Object), `_instances` (Object), `_isPlaying` (Boolean), `_buffer` (Object), `_loaded`, `_loading` (Boolean)

---

### Suite 6: Stability

```bash
MCPCALL --tool browser_get_console_logs --args '{"count":30,"level":["error","warn"]}' 2>/dev/null
```

Assert: No application-level errors. Audio autoplay warnings and pre-existing 404 resource errors from page load are acceptable.

---

## Step 5: Cleanup & Results

Kill the dev server:

```bash
kill $(lsof -t -i :<PORT>) 2>/dev/null
```

Output a summary table:

```
| Suite                    | Result    |
|--------------------------|-----------|
| 1. Audio Loading         | PASS/FAIL |
| 2. Playback Trigger      | PASS/FAIL |
| 3. Stop                  | PASS/FAIL |
| 4. System Registration   | PASS/FAIL |
| 5. Component Schema      | PASS/FAIL |
| 6. Stability             | PASS/FAIL |
```

If any suite fails, include which assertion failed and actual vs expected values.

---

## Recovery

If at any point a transient error occurs (server crash, WebSocket timeout, connection refused, etc.) that is NOT caused by a source code bug:

1. Kill the dev server: `kill $(lsof -t -i :<PORT>) 2>/dev/null`
2. Restart: re-run Step 2 to start a fresh dev server (port may change)
3. Re-run the Pre-test Setup (reload, accept session)
4. Retry the failed suite

Only give up after one retry attempt per suite. If the same suite fails twice, mark it FAIL and continue to the next suite.

---

## Known Issues & Workarounds

### Request flags are one-shot

`_playRequested`, `_pauseRequested`, and `_stopRequested` are consumed by the AudioSystem within one frame. The `ecs_set_component` response may already show `newValue: false`.

### Short sounds finish before query

Non-looping sounds may finish playing before you can query `_isPlaying`. Set `loop: true` before playing to observe a persistent `_isPlaying: true` state.

### Stop priority

If `_stopRequested` and `_playRequested` are set simultaneously, stop wins.

### Audio output not verifiable

IWER runs in a browser context where the AudioContext may be suspended until a user gesture. The MCP tools can verify ECS state transitions but cannot confirm actual audio output.

### Audio example uses GLXF level

The audio example loads entities from `./glxf/Composition.glxf`. Entities are not created in index.js — they come from the GLXF composition. Use `ecs_find_entities` to discover them dynamically.

### Boolean values must be JSON booleans

When setting boolean fields (like `_playRequested`, `loop`, `_stopRequested`) via `ecs_set_component`, the `value` must be a JSON boolean (`true`), not a string (`"true"`). Strings silently fail.

### Entity indices change on reload

Never cache entity indices across page reloads. Always re-discover via `ecs_find_entities`.