// Test audio system (AudioSource loading, playback state, stop, spatial audio) against the audio example using the iwsdk CLI.
MUST read this skill BEFORE developing VR/MR/browser-first 3D applications using IWSDK (Immersive Web SDK). Covers project scaffolding, headless browser setup, CLI tools, reference system, ECS debugging, XR emulation, verification workflows, deployment, and known issues.
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| name | test-audio |
| description | Test audio system (AudioSource loading, playback state, stop, spatial audio) against the audio example using the iwsdk CLI. |
| argument-hint | [--suite loading|playback|stop|all] |
Run 6 test suites covering audio loading, playback trigger, stop, system registration, component schema, and stability.
Configuration:
$IWSDK_REPO_ROOT/examples/audioTool calls: every tool call is npx iwsdk <subcommand> [--input-json '<JSON>'] [--timeout <ms>], run from inside the example workspace (cwd $EXAMPLE_DIR). The CLI auto-discovers the IWSDK app root from cwd, so no path tricks are required. Run npx iwsdk mcp inspect from the example to discover available tools and their CLI subcommands.
<JSON> is a JSON object string. Omit --input-json if no arguments are needed.{ok, workspaceRoot, operation, result}. Parse it to check assertions.--timeout 20000 for operations that may take longer (reload, xr enter, screenshot).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 CLI 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.
cd $IWSDK_REPO_ROOT/examples/audio && npm run fresh:install
Wait for this to complete before proceeding.
Start the dev server as a background task using the Bash tool's run_in_background: true parameter:
cd $IWSDK_REPO_ROOT/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). You can also run npx iwsdk dev status from the example directory until state.running becomes true. You do not need to extract or manage the port yourself; subsequent commands resolve the active runtime through the CLI automatically.
If the server fails to start within 60 seconds, report FAIL for all suites and skip to Step 5.
npx iwsdk ecs systems 2>/dev/null
This must return JSON with a list of systems. If it fails:
Run these commands in order:
npx iwsdk browser reload --timeout 20000 2>/dev/null
Then: sleep 3
npx iwsdk xr enter --timeout 20000 2>/dev/null
Then: sleep 2
npx iwsdk browser logs --input-json '{"count":20,"level":["error"]}' 2>/dev/null
Assert: No error-level logs. Audio autoplay warnings are acceptable.
Test 1.1: Find Audio Entity
npx iwsdk ecs find --input-json '{"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
npx iwsdk ecs query --input-json '{"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 = 1positional = trueTest 1.3: Pool Created
Assert: _pool exists with available array matching maxInstances.
Test 2.1: Request Play
npx iwsdk ecs set-component --input-json '{"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:
npx iwsdk ecs set-component --input-json '{"entityIndex":<audio>,"componentId":"AudioSource","field":"loop","value":true}' 2>/dev/null
npx iwsdk ecs set-component --input-json '{"entityIndex":<audio>,"componentId":"AudioSource","field":"_playRequested","value":true}' 2>/dev/null
Then query:
npx iwsdk ecs query --input-json '{"entityIndex":<audio>,"components":["AudioSource"]}' 2>/dev/null
Assert: _isPlaying = true (looping sound keeps playing).
Test 3.1: Request Stop
npx iwsdk ecs set-component --input-json '{"entityIndex":<audio>,"componentId":"AudioSource","field":"_stopRequested","value":true}' 2>/dev/null
Assert: _stopRequested consumed, _isPlaying becomes false.
npx iwsdk ecs systems 2>/dev/null
Assert:
enableDistanceCulling, cullingDistanceMultiplieraudioEntities >= 1npx iwsdk ecs components 2>/dev/null
Assert AudioSource fields:
src (FilePath), volume (Float32), loop (Boolean), autoplay (Boolean)positional (Boolean), refDistance, rolloffFactor, maxDistance, distanceModel, coneInnerAngle, coneOuterAngle, coneOuterGainplaybackMode (Enum), maxInstances (Int8), crossfadeDuration (Float32), instanceStealPolicy (Enum)_playRequested, _pauseRequested, _stopRequested (Boolean), _fadeIn, _fadeOut (Float32)_pool (Object), _instances (Object), _isPlaying (Boolean), _buffer (Object), _loaded, _loading (Boolean)npx iwsdk browser logs --input-json '{"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.
Kill the dev server:
cd $IWSDK_REPO_ROOT/examples/audio && npx iwsdk dev down
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.
If at any point a transient error occurs (server crash, WebSocket timeout, connection refused, etc.) that is NOT caused by a source code bug:
cd $IWSDK_REPO_ROOT/examples/audio && npx iwsdk dev downOnly give up after one retry attempt per suite. If the same suite fails twice, mark it FAIL and continue to the next suite.
_playRequested, _pauseRequested, and _stopRequested are consumed by the AudioSystem within one frame. The npx iwsdk ecs set-component response may already show newValue: false.
Non-looping sounds may finish playing before you can query _isPlaying. Set loop: true before playing to observe a persistent _isPlaying: true state.
If _stopRequested and _playRequested are set simultaneously, stop wins.
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.
The audio example loads entities from ./glxf/Composition.glxf. Entities are not created in index.js — they come from the GLXF composition. Use npx iwsdk ecs find to discover them dynamically.
When setting boolean fields (like _playRequested, loop, _stopRequested) via npx iwsdk ecs set-component, the value must be a JSON boolean (true), not a string ("true"). Strings silently fail.
Never cache entity indices across page reloads. Always re-discover via npx iwsdk ecs find.