test-locomotion

Test locomotion system (slide, snap turn, teleport, jump) against the locomotion example using the iwsdk CLI.

npx skills add https://github.com/facebook/immersive-web-sdk --skill test-locomotion

Locomotion System Test

Run 6 test suites covering slide movement, snap turn, teleport, jump, system registration, and stability.

Configuration:

  • EXAMPLE_DIR: $IWSDK_REPO_ROOT/examples/locomotion

Tool 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.
  • Output is JSON on stdout: {ok, workspaceRoot, operation, result}. Parse it to check assertions.
  • Use --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.


Step 1: Install Dependencies

cd $IWSDK_REPO_ROOT/examples/locomotion && 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:

cd $IWSDK_REPO_ROOT/examples/locomotion && 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.


Step 3: Verify Connectivity

npx iwsdk ecs 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. npx iwsdk browser reload --timeout 20000 2>/dev/null Then: sleep 3

  2. npx iwsdk xr enter --timeout 20000 2>/dev/null Then: sleep 2

  3. npx iwsdk browser logs --input-json '{"count":20,"level":["error","warn"]}' 2>/dev/null Assert: No error-level logs.

Verify Locomotion Setup

npx iwsdk ecs find --input-json '{"withComponents":["LocomotionEnvironment"]}' 2>/dev/null

Assert: At least 1 entity. Save as <env>.

npx iwsdk ecs query --input-json '{"entityIndex":<env>,"components":["LocomotionEnvironment"]}' 2>/dev/null

Assert: _initialized = true, _envHandle > 0.

npx iwsdk ecs systems 2>/dev/null

Assert:

  • LocomotionSystem (priority -5)
  • TurnSystem (priority 0)
  • SlideSystem (priority 0)
  • TeleportSystem (priority 0)

Input Mapping Reference

ActionControllerInputTool
Slide forwardLeftThumbstick Y = -1npx iwsdk xr set-gamepad-state axes [{0, 0}, {1, -1}]
Slide backwardLeftThumbstick Y = 1npx iwsdk xr set-gamepad-state axes [{0, 0}, {1, 1}]
Snap turn rightRightThumbstick X = 1 (edge)npx iwsdk xr set-gamepad-state axes [{0, 1}, {1, 0}]
Snap turn leftRightThumbstick X = -1 (edge)npx iwsdk xr set-gamepad-state axes [{0, -1}, {1, 0}]
Teleport activateRightThumbstick Y = 1 (down)npx iwsdk xr set-gamepad-state axes [{0, 0}, {1, 1}]
JumpRightA button (index 3)npx iwsdk xr set-gamepad-state buttons [{3, 1, true}]

Suite 1: Slide Movement (Left Thumbstick)

Test 1.1: Slide Forward

npx iwsdk browser screenshot --timeout 20000 2>/dev/null

Save as "before slide".

npx iwsdk xr set-gamepad-state --input-json '{"device":"controller-left","axes":[{"index":0,"value":0},{"index":1,"value":-1}]}' 2>/dev/null

Then: sleep 1

npx iwsdk browser screenshot --timeout 20000 2>/dev/null

Save as "after slide".

Assert: Screenshots show scene moving closer (player moved forward).

Test 1.2: Stop Sliding

npx iwsdk xr set-gamepad-state --input-json '{"device":"controller-left","axes":[{"index":0,"value":0},{"index":1,"value":0}]}' 2>/dev/null

Assert: Player stops moving (subsequent screenshots are identical).

Test 1.3: Slide Backward

npx iwsdk xr set-gamepad-state --input-json '{"device":"controller-left","axes":[{"index":0,"value":0},{"index":1,"value":1}]}' 2>/dev/null

Then: sleep 1

npx iwsdk browser screenshot --timeout 20000 2>/dev/null

Assert: Scene moves away (player retreated).

Release:

npx iwsdk xr set-gamepad-state --input-json '{"device":"controller-left","axes":[{"index":0,"value":0},{"index":1,"value":0}]}' 2>/dev/null

Suite 2: Snap Turn (Right Thumbstick Left/Right)

Test 2.1: Snap Turn Right

npx iwsdk browser screenshot --timeout 20000 2>/dev/null

Save as "before turn".

npx iwsdk xr set-gamepad-state --input-json '{"device":"controller-right","axes":[{"index":0,"value":1},{"index":1,"value":0}]}' 2>/dev/null

Then: sleep 0.3

npx iwsdk browser screenshot --timeout 20000 2>/dev/null

Save as "after turn right".

Assert: View rotated ~45 degrees clockwise.

Test 2.2: Release + Snap Turn Left

IMPORTANT: Must release first for edge trigger reset.

npx iwsdk xr set-gamepad-state --input-json '{"device":"controller-right","axes":[{"index":0,"value":0},{"index":1,"value":0}]}' 2>/dev/null

Then: sleep 0.3

Push left:

npx iwsdk xr set-gamepad-state --input-json '{"device":"controller-right","axes":[{"index":0,"value":-1},{"index":1,"value":0}]}' 2>/dev/null

Then: sleep 0.3

npx iwsdk browser screenshot --timeout 20000 2>/dev/null

Assert: View rotated ~45 degrees counter-clockwise (back to roughly original heading).

Release thumbstick:

npx iwsdk xr set-gamepad-state --input-json '{"device":"controller-right","axes":[{"index":0,"value":0},{"index":1,"value":0}]}' 2>/dev/null

Suite 3: Teleport (Right Thumbstick Down)

Precondition: The right controller must NOT be pointing at any interactable entity.

Test 3.1: Setup — Point Controller at Floor

npx iwsdk xr set-transform --input-json '{"device":"controller-right","position":{"x":0.25,"y":1.5,"z":-0.3},"orientation":{"pitch":-45,"roll":0,"yaw":0}}' 2>/dev/null

Test 3.2: Activate Teleport Arc

npx iwsdk browser screenshot --timeout 20000 2>/dev/null

Save as "before teleport".

npx iwsdk xr set-gamepad-state --input-json '{"device":"controller-right","axes":[{"index":0,"value":0},{"index":1,"value":1}]}' 2>/dev/null

Then: sleep 1

Test 3.3: Release to Teleport

npx iwsdk xr set-gamepad-state --input-json '{"device":"controller-right","axes":[{"index":0,"value":0},{"index":1,"value":0}]}' 2>/dev/null

Then: sleep 0.5

npx iwsdk browser screenshot --timeout 20000 2>/dev/null

Assert: Player position changed (view is from a different location).


Suite 4: Jump (A Button on Right Controller)

Test 4.1: Press A Button

npx iwsdk xr set-gamepad-state --input-json '{"device":"controller-right","buttons":[{"index":3,"value":1,"touched":true}]}' 2>/dev/null

Then: sleep 0.3

npx iwsdk browser screenshot --timeout 20000 2>/dev/null
npx iwsdk xr set-gamepad-state --input-json '{"device":"controller-right","buttons":[{"index":3,"value":0,"touched":false}]}' 2>/dev/null

Assert: View may show momentary elevation change.


Suite 5: System Registration & Config

npx iwsdk ecs systems 2>/dev/null

Assert:

  • LocomotionSystem at priority -5
  • TurnSystem at priority 0 with config keys: turningMethod, turningAngle, turningSpeed
  • SlideSystem at priority 0 with config keys: locomotor, inputProvider, maxSpeed, comfortAssist, enableJumping
  • TeleportSystem at priority 0 with config keys: rayGravity, locomotor, inputProvider

Verify Elevator component and ElevatorSystem:

npx iwsdk ecs find --input-json '{"withComponents":["Elevator"]}' 2>/dev/null

Assert: At least 1 entity (the oscillating platform).


Suite 6: Stability

npx iwsdk browser logs --input-json '{"count":30,"level":["error","warn"]}' 2>/dev/null

Assert: No application-level errors or warnings. Pre-existing 404 resource errors from page load are acceptable.


Step 5: Cleanup & Results

Kill the dev server:

cd $IWSDK_REPO_ROOT/examples/locomotion && npx iwsdk dev down

Output a summary table:

| Suite                     | Result    |
|---------------------------|-----------|
| 1. Slide Movement         | PASS/FAIL |
| 2. Snap Turn              | PASS/FAIL |
| 3. Teleport               | PASS/FAIL |
| 4. Jump                   | PASS/FAIL |
| 5. System Registration    | 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. Stop the dev server: cd $IWSDK_REPO_ROOT/examples/locomotion && npx iwsdk dev down
  2. Restart: re-run Step 2 to start a fresh dev server
  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

Locomotion moves XR origin, not headset

Headset position stays constant (relative to XR origin). Verify movement via screenshots.

Teleport blocked by interactable hover

Position controller away from interactables before testing teleport.

Snap turn is edge-triggered

Must reset to center between turns. Holding the stick only fires one turn.

Thumbstick Y axis convention

Y = -1 is forward, Y = 1 is backward. For teleport, Y = 1 activates the arc.

Entity indices change on reload

Never cache entity indices across page reloads. Always re-discover via npx iwsdk ecs find.

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