Refactoring

Law of Demeter

Avoid deep access chains like this.hot.view.wt.wtTable.holder. Each layer should only talk to its immediate neighbors. If you find yourself reaching through multiple objects, introduce a method on the intermediate layer that provides what you need.

Refactoring Patterns

Plugin extraction: When logic in core.js or a large plugin grows beyond a single responsibility, move it into a dedicated plugin. Register new hooks so the extracted plugin communicates without tight coupling.

Performance:

• Replace arr.push(...largeArray) with a forEach loop -- spread causes stack overflow with 10k+ elements.
• Batch render cycles using batch(), batchRender(), suspendRender()/resumeRender().
• Reduce DOM reads and writes. Batch scroll-related work inside requestAnimationFrame.

Modernization:

• Use #privateFields instead of @private JSDoc annotations (exception: when # measurably hurts performance).
• Use arrow-function class fields for hook and event callbacks instead of .bind(this).
• Use optional chaining (?.) only when a value is genuinely optional by design, not as a blanket safety net.

API redesign: When renaming or replacing an API, keep the old name working. See the backward compatibility section below.

Breaking Changes Protection

These rules are non-negotiable when refactoring:

Clarity and Maintainability

• Keep cognitive complexity at 15 or below per function (Sonar metric). Extract helpers or use early-return guards when a function exceeds this limit.
• Favor clarity over cleverness. A slightly longer but readable solution is better than a compact but obscure one.
• Reuse existing helpers from src/helpers/. Check what already exists before writing new utility functions.
• Follow the established method ordering: public methods first, then private listeners.

Testing After Refactoring

Refactored code must maintain full test coverage. For every change:

• Unit tests (*.unit.js): test extracted helpers, strategies, and pure logic in isolation.
• E2E tests (*.spec.js): verify the feature still works end-to-end in the browser. All it() callbacks must be async.
• Backward compatibility tests: verify that legacy API names, CSS classes, and option names still work after the refactor.
• Performance tests: for data-heavy paths, add unit tests with 50k+ rows to catch regressions.