pixijs-ticker-testing

name: pixijs-ticker-testing description: PixiJS Ticker test patterns and pitfalls. Use when writing or debugging tests that involve PixiJS Ticker updates. allowed-tools: Read

PixiJS Ticker Test Guidelines

Key Concept

ticker.update() argument is absolute time, not relative time.

• Calling multiple times with the same value ignores subsequent calls
• The ticker only fires when a larger value is passed
• When called without arguments, ticker.update() uses performance.now() as default
• Reference: https://pixijs.download/release/docs/ticker.Ticker.html#update

Test Patterns

Pre-test Reset

beforeEach(async () => {
  ticker = new Ticker();
  ticker.autoStart = false;

  // ... manager initialization ...

  ticker.stop();
  ticker.update(0); // Reset to time 0
});

Single and Multiple Updates

// Single update with explicit time
ticker.update(1);

// Multiple updates: always increment absolute time
ticker.update(1);
ticker.update(2); // Must be larger than 1
ticker.update(3); // Must be larger than 2

Loop Usage

// Correct: incremental time
for (let i = 0; i < 60; i++) {
  manager.requestRender(billboard);
  ticker.update(i + 1); // 1, 2, 3, ...
}

// WRONG: same time - only fires on first iteration
for (let i = 0; i < 60; i++) {
  manager.requestRender(billboard);
  ticker.update(1); // Ignored after first call!
}

Batch Processing

if (i % 10 === 9) {
  ticker.update(Math.floor(i / 10) + 1); // Increment per batch
}

// Final render
ticker.update(100); // Sufficiently large value

Why Explicit Time Values?

Using explicit time values (e.g., ticker.update(1), ticker.update(2)) instead of performance.now() provides:

• Predictable behavior: Consistent across environments
• Deterministic results: Same input always produces same output
• Debugging ease: Easy to trace which update call caused an issue
• Performance: No dependency on system clock resolution