mapbox / mapbox/supercluster

Nested geoJson properties are copied by reference

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enhancement
Dominant language
JavaScript
Stars
2.4k
Forks
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PR merge metrics
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Description

When cloning a cluster in _map the assign function only shallow clones an object, copying sub-objects or arrays by reference. This can result in mutations to the original object when the accumulator is mutated in reduce.

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Research direction

The relevant entry point is _map, where assign shallow-clones objects before the accumulator is mutated in reduce. Reproduce the nested-object or array case and verify that changing the accumulator no longer changes the original object.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript
Domain
data
Issue type
Bug
Difficulty
2/5
Estimated time
1-3 hours
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
50/100

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