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Rule priority, scope & exceptions
Use this to align rules with the senior-level structure (P0/P1/P2, scope, exceptions/tradeoffs).
frontend ruleP1universalStack: javascript
arraysdeduplicationreactcorrectness
Deduplicate by id when merging collections
When concatenating fetched batches, skip items whose id is already present so React keys stay unique and content isn't doubled.
PR: frontpage-web · org-mining-hist-2026-06Created: Jun 18, 2026
Bad example
Old codetypescript
| 1 | newArticles.forEach(a => articlesArray.push(a)); // duplicates possible |
Explanation (EN)
Objašnjenje (HR)
Good example
New codetypescript
| 1 | newArticles.forEach(a => !articlesArray.find(x => x.id === a.id) && articlesArray.push(a)); |
Explanation (EN)
Objašnjenje (HR)