astro44/test-create-fixture

test-create-fixture - Component Test Fixture Creator

Creates HTML test fixture files for UI components. Used by dev agents during TDD to create isolated test pages before implementation.

Input Schema

{
  "project_dir": "/path/to/project",
  "ticket_id": "TICKET-XXX_A.1",
  "component_path": "src/components/impact/MetricCard.js",
  "fixture_path": "src/tests/metric-card.html",
  "component_name": "MetricCard",
  "component_class": "MetricCard",
  "acceptance_criteria": [
    {"id": "AC-001", "description": "Counter animates from 0 to target"},
    {"id": "AC-002", "description": "Displays unit label correctly"}
  ]
}

CRITICAL: Use Absolute URL Paths (NOT Relative)

NEVER use relative paths like ../../ in fixture imports.

The server runs from src/ directory, making src/ the web root:

• src/tests/*.html → served at /tests/*.html
• src/components/**/*.js → served at /components/**/*.js

WHY relative paths break:

fixture_path: src/tests/metric-card.html
component_path: src/components/impact/MetricCard.js

WRONG: ../../components/impact/MetricCard.js
       → resolves to project_root/components/impact/MetricCard.js (OUTSIDE src/)
       → FILE NOT FOUND

RIGHT: /components/impact/MetricCard.js
       → resolves from server root (src/) to src/components/impact/MetricCard.js
       → FILE FOUND ✓

Instructions

1. Locate Template

# Template location (in order of priority):
# 1. Project-specific: {project_dir}/templates/tests/component-fixture.html
# 2. Harness: {project_dir}/harness/templates/component-fixture.html
# 3. Global: templates/project/tests/web/component-fixture.template.html

2. Process Template Variables

Replace mustache-style variables in template:

| Variable | Source | Example | |----------|--------|---------| | {{TICKET_ID}} | input.ticket_id | TICKET-OXY-003_A.1 | | {{COMPONENT_NAME}} | input.component_name | MetricCard | | {{COMPONENT_PATH}} | Absolute URL from server root | /components/impact/MetricCard.js | | {{COMPONENT_CLASS}} | input.component_class | MetricCard | | {{COMPONENT_CSS}} | CSS absolute URL | /styles/metric-card.css | | {{COMPONENT_OPTIONS}} | Default init options | {} or from ticket | | {{COMPONENT_SELECTOR}} | data-* attribute name (kebab-case) | circular-progress | | {{#ACCEPTANCE_CRITERIA}} | Loop over ACs | Creates test sections | | {{AC_ID}} | Each AC ID | AC-001 | | {{AC_DESCRIPTION}} | Each AC description | Counter animates... |

3. Calculate Absolute URL Paths

CRITICAL: Check for import_prefix in context first!

The import_prefix context variable tells you if the server needs a path prefix (e.g., /src).

// FIRST: Check if import_prefix is provided in context
// If import_prefix = "/src", paths need the /src prefix
// If import_prefix = "", server serves from src/ directly

function toAbsoluteUrl(filePath, importPrefix) {
  // Remove src/ prefix if present to get relative path
  let relativePath = filePath;
  if (filePath.startsWith('src/')) {
    relativePath = filePath.slice(4); // Remove 'src/'
  }

  // Apply import_prefix if provided (e.g., "/src" when server runs from project root)
  if (importPrefix) {
    return importPrefix + '/' + relativePath;
  }

  // Default: assume server runs from src/, no prefix needed
  return '/' + relativePath;
}

// Examples WITH import_prefix="/src" (server at project root):
// src/components/impact/MetricCard.js → /src/components/impact/MetricCard.js
// src/styles/metric-card.css → /src/styles/metric-card.css

// Examples WITHOUT import_prefix (server at src/):
// src/components/impact/MetricCard.js → /components/impact/MetricCard.js
// src/styles/metric-card.css → /styles/metric-card.css

Always check context for import_prefix before generating import paths!

4. Generate AC Test Sections

For each acceptance criterion, create a test section:

<div class="test-section" id="test-AC-001">
  <h2>AC-001: Counter animates from 0 to target</h2>
  <div data-test-scenario="ac-001"></div>
</div>

5. Write Fixture File

// Ensure directory exists
const fixtureDir = path.dirname(fixturePath);
await fs.mkdir(fixtureDir, { recursive: true });

// Write processed template
await fs.writeFile(fixturePath, processedTemplate);

Output Format

{
  "skill": "test-create-fixture",
  "status": "success|failure",
  "fixture_created": "src/tests/metric-card.html",
  "template_used": "templates/project/tests/web/component-fixture.template.html",
  "variables_replaced": {
    "TICKET_ID": "TICKET-OXY-003_A.1",
    "COMPONENT_NAME": "MetricCard",
    "COMPONENT_PATH": "/components/impact/MetricCard.js",
    "ACCEPTANCE_CRITERIA": 2
  },
  "test_sections": ["AC-001", "AC-002"],
  "warnings": [],
  "next_action": "validate_fixture"
}

Happy Path Only (CRITICAL)

Initial fixtures focus on happy path ONLY. Edge case testing is deferred to later phases.

What to Include (Happy Path)

• Primary data loading with valid endpoints
• Standard component initialization
• Default configurations
• Expected successful responses

What to Defer (Edge Cases)

• Missing file/endpoint tests (AC descriptions mentioning "missing", "invalid", "error handling")
• Error recovery scenarios
• Timeout/failure handling
• Malformed input validation

Handling Edge Case ACs

When an AC describes edge case behavior (missing files, errors, invalid data), do NOT test it directly. Instead:

// AC-3: "No runtime errors when data file is missing"
// DEFERRED - mark as deferred, don't request missing file
setOutput('ac-3', JSON.stringify({
  status: 'deferred',
  note: 'Edge case test deferred until happy path validated'
}, null, 2));

Rationale: Early TDD phases validate that components work correctly with valid inputs. Edge case testing requires additional infrastructure (mock servers, error injection) that may not exist yet.

Fixture Requirements

The generated fixture MUST include:

1. Isolated component - Only the target component, no page context
2. Real imports - Import from actual src/ path, not copies
3. Test sections per AC - Each acceptance criterion gets a section
4. data-testid attributes - For Playwright selection
5. Status indicator - Shows init success/failure (#test-status.success/.error)
6. Playwright hooks - CRITICAL for test access:

Required Window Globals (CRITICAL)

// Set SYNCHRONOUSLY (before async init) for browser timing consistency
window.__testModule = {
  ComponentClass,        // The class constructor
  initComponentFactory,  // Factory function if available
  ...otherExports        // All named exports from module
};

// Set AFTER async init completes
window.__testInstances = [...];  // Array of initialized instances
window.__getTestInstance = () => instances[0];
window.__getTestInstances = () => instances;
window.__isInitialized = () => initComplete && !error;
window.__getInitError = () => initError;

Why __testModule is CRITICAL:

• ES6 module loading timing varies by browser (Chromium is slower)
• Tests use page.waitForFunction(() => window.__testModule) to wait for module
• If not set synchronously, tests fail with race conditions
• Chromium especially affected (19 failures vs WebKit's 4)

Example Generated Fixture

<!DOCTYPE html>
<html lang="en">
<head>
  <title>MetricCard Test - TICKET-OXY-003_A.1</title>
  <!-- ABSOLUTE URLs - server root is src/ -->
  <link rel="stylesheet" href="/styles/impact/metric-card.css">
</head>
<body>
  <div class="test-container">
    <h1>MetricCard Test</h1>

    <div class="test-section" id="test-AC-001">
      <h2>AC-001: Counter animates from 0 to target</h2>
      <div data-testid="ac-001-container"></div>
    </div>

    <div class="test-section" id="test-AC-002">
      <h2>AC-002: Displays unit label correctly</h2>
      <div data-testid="ac-002-container"></div>
    </div>

    <div id="test-status">Loading...</div>
  </div>

  <script type="module">
    // ABSOLUTE URL - NOT relative! Server root is src/
    import { MetricCard } from '/components/impact/MetricCard.js';
    // ... initialization code
  </script>
</body>
</html>

Token Efficiency

• Template-based generation (no LLM needed for structure)
• ~2-5 second execution
• Returns ready-to-use HTML fixture