Rules Hub
Code Ruleset
← Back to all rules
Rule priority, scope & exceptions
Use this to align rules with the senior-level structure (P0/P1/P2, scope, exceptions/tradeoffs).
frontend ruleP1stack specificStack: JavaScript
globalsanalyticscorrectness
Augment a shared global (like dataLayer) instead of overwriting it
Push onto an existing global array and guard its existence rather than reassigning it, which would clobber data other code set.
PR: hegnar-bellsheep-web · org-mining-hist-2026-06Created: Jun 18, 2026
Bad example
Old codejs
| 1 | window.dataLayer = { event: 'pageview' }; |
Explanation (EN)
Replacing the queue discards events another script already recorded.
Objašnjenje (HR)
Good example
New codejs
| 1 | window.dataLayer = window.dataLayer || []; |
| 2 | window.dataLayer.push({ event: 'pageview' }); |
Explanation (EN)
Objašnjenje (HR)
Notes (EN)
For a documented shared global queue, preserve the existing valid queue and append through its supported interface. Check initialization order and the expected value shape.
Exceptions / Tradeoffs (EN)
Do not silently treat an arbitrary truthy object as an array; follow the owner's contract for invalid or preinitialized values. Do not expose secrets in analytics events.