rtfeldman/seamless-immutable

Compare equality of two immutable items

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#186 opened on Dec 15, 2016

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enhancementhelp wanted

Description

This is essentially https://github.com/rtfeldman/seamless-immutable/issues/1, but am opening another issue for visibility as the prior is closed and there's no attention on it.

I'd like to have a method like Immutable.equals(a, b, deepWalk?) to compare if two objects are equal.

This is useful for perf optimization in React if I have a deeply nested object coming down (ignore best practices for props/how loaded an object should be going through to a component for the sake of argument here), where I can compare the new object to the current one in shouldComponentUpdate().

In some of my old components, I'm using immutable.js against the objects, and using the .equals() to compare them as part of a decision if the component should be updating or not.

Contributor guide

Tech stack
javascript
Domain
frontend
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
JavaScript basicsUnderstanding of immutable data structures
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50
Research direction
Review the linked closed issue #1 for prior discussion. Examine the existing source code in the repository (e.g., `src/immutable.js`) to understand the internal structure of immutable objects. Design a method `Immutable.equals(a, b, deepWalk?)` that performs deep equality, handling nested immutable objects and optional deep walk parameter. Consider edge cases like circular references and performance optimization for React's `shouldComponentUpdate`.