immutability
Immutability
Overview
Never mutate. Always return new objects.
Mutation causes bugs that are hard to track - when objects change unexpectedly, debugging becomes a nightmare. Immutability makes state changes explicit and predictable.
When to Use
- Modifying objects or arrays
- Updating state in React/Redux
- Function receives object as parameter
- Data shared between multiple parts of code
The Iron Rule
NEVER mutate objects or arrays. ALWAYS return new copies with changes.
More from yanko-belov/code-craft
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Use when writing similar code in multiple places. Use when copy-pasting code. Use when making the same change in multiple locations.
84lazy-loading
Use when loading all data upfront. Use when initial page load is slow. Use when fetching data that might not be needed.
54keep-it-simple
Use when tempted to write clever code. Use when solution feels complex. Use when showing off skills instead of solving problems.
51separation-of-concerns
Use when component does too many things. Use when mixing data fetching, logic, and presentation. Use when code is hard to test.
44single-responsibility-principle
Use when creating or modifying classes, modules, or functions. Use when feeling pressure to add functionality to existing code. Use when class has multiple reasons to change.
39fail-fast
Use when handling errors. Use when tempted to catch and swallow exceptions. Use when returning default values to hide failures.
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