mcpbeat

Test Environment

facebook/test-environment

Test environment system (authored DomeGradient and IBLGradient, component schemas) against the poke example using the iwsdk CLI.

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on the repository, not the skill itself

Install

one command, takes just this skill from the repository
npx skills add https://github.com/facebook/immersive-web-sdk --skill test-environment

What it tells the agent to use

found in the instruction text
Bash runs shell commands — read the instruction before connecting

The instruction itself

20 sections, as written by the author

Environment System Test

Run 6 test suites covering authored environment verification, system registration, component registration, scene hierarchy, ECS data modification, and stability.

Configuration:

  • EXAMPLE_DIR: $IWSDK_REPO_ROOT/examples/poke

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.

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

cd $IWSDK_REPO_ROOT/examples/poke && 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/poke && 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:

  • Check the dev server output for errors
  • Try killing and restarting the server (Step 2)
  • 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:

  • 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","warn"]}' 2>/dev/null

Assert: No error-level logs.


Suite 1: Authored Environment Verification

Test 1.1: Find LevelRoot Dynamically

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

Assert: Exactly 1 entity. Save its entityIndex as <root>.

Test 1.2: LevelRoot Has Environment Components

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

Assert: Both components are present with the values explicitly authored in

public/scenes/poke.iwsdk.scene.json:

DomeGradient defaults:

| Field | Expected Value |

|-------|---------------|

| sky | [0.2423, 0.6172, 0.8308, 1.0] (soft blue) |

| equator | [0.6584, 0.7084, 0.7913, 1.0] (gray-blue) |

| ground | [0.807, 0.7758, 0.7454, 1.0] (warm beige) |

| intensity | 1.0 |

| _needsUpdate | false (already processed) |

IBLGradient defaults:

| Field | Expected Value |

|-------|---------------|

| sky | [0.6902, 0.749, 0.7843, 1.0] (soft blue-gray — different from DomeGradient!) |

| equator | [0.6584, 0.7084, 0.7913, 1.0] (same as DomeGradient) |

| ground | [0.807, 0.7758, 0.7454, 1.0] (same as DomeGradient) |

| intensity | 1.0 |

| _needsUpdate | false |

Key detail: DomeGradient and IBLGradient have different sky defaults.


Suite 2: System Registration

Test 2.1: EnvironmentSystem Present

npx iwsdk ecs systems 2>/dev/null

Assert:

  • EnvironmentSystem at priority 0
  • Query entity counts: domeGradients: 1, iblGradients: 1, domeTextures: 0, iblTextures: 0

Suite 3: Component Registration

Test 3.1: All Environment Components Registered

npx iwsdk ecs components 2>/dev/null

Assert these components exist with correct schemas:

| Component | Key Fields |

| -------------- | ------------------------------------------------------------------------------------------------------------ |

| DomeGradient | sky (Color), equator (Color), ground (Color), intensity (Float32), _needsUpdate (Boolean) |

| DomeTexture | src (FilePath), blurriness (Float32), intensity (Float32), rotation (Vec3), _needsUpdate (Boolean) |

| IBLGradient | sky (Color), equator (Color), ground (Color), intensity (Float32), _needsUpdate (Boolean) |

| IBLTexture | src (FilePath, default: "room"), intensity (Float32), rotation (Vec3), _needsUpdate (Boolean) |


Suite 4: Scene Hierarchy

Test 4.1: Dome Mesh in Scene

npx iwsdk scene runtime-hierarchy --input-json '{"maxDepth":2}' 2>/dev/null

The gradient dome mesh is added directly to the scene (not under LevelRoot). Look for an unnamed mesh node at the scene root level.


Suite 5: ECS Data Modification

Test 5.1: Modify DomeGradient Sky Color

npx iwsdk ecs set-component --input-json '{"entityIndex":<root>,"componentId":"DomeGradient","field":"sky","value":"[1.0, 0.0, 0.0, 1.0]"}' 2>/dev/null

Then verify:

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

Assert: sky = [1.0, 0.0, 0.0, 1.0]

Test 5.2: Modify IBLGradient Intensity

npx iwsdk ecs set-component --input-json '{"entityIndex":<root>,"componentId":"IBLGradient","field":"intensity","value":"2.0"}' 2>/dev/null
npx iwsdk ecs set-component --input-json '{"entityIndex":<root>,"componentId":"IBLGradient","field":"_needsUpdate","value":true}' 2>/dev/null

Assert: ECS value updates.


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/poke && npx iwsdk dev down

Output a summary table:

| Suite                    | Result    |
|--------------------------|-----------|
| 1. Authored Environment  | PASS/FAIL |
| 2. System Registration   | PASS/FAIL |
| 3. Component Registration| PASS/FAIL |
| 4. Scene Hierarchy       | PASS/FAIL |
| 5. ECS Data Modification | 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:

  • Stop the dev server: cd $IWSDK_REPO_ROOT/examples/poke && npx iwsdk dev down
  • Restart: re-run Step 2 to start a fresh dev server
  • Re-run the Pre-test Setup (reload, accept session)
  • 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

Live gradient color changes don't update visuals

Setting DomeGradient/IBLGradient color fields via npx iwsdk ecs set-component updates the ECS data but does NOT update the Three.js shader uniforms. Testing is limited to data verification.

\_needsUpdate consumed immediately

The _needsUpdate flag is consumed by the EnvironmentSystem and reset to false. The response may already show newValue: false.

Environment components are explicit

LevelSystem does not synthesize dome or IBL components. Their absence is

meaningful, and each scene must author the background and image-based lighting

it wants on the level root. The poke fixture scene includes both gradient

components explicitly.

Entity indices change on reload

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

Boolean values must be JSON booleans

When setting boolean fields (like _needsUpdate) via npx iwsdk ecs set-component, the value must be a JSON boolean (true), not a string ("true"). Strings silently fail.

How to use it

Copy the folder

Take facebook/test-environment from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.

Install what it needs

The instructions reference npx. Without those the skill loads but fails at the first command.