rust-lang/rust-clippy

FR: redundant_field_names should distinguish between all and some fields matching

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#3422 opened on Nov 10, 2018

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 (1 comment) (4 reactions) (1 assignee)Rust (10,406 stars) (1,391 forks)batch import
C-enhancementL-stylegood first issue

Description

redundant_field_names fires on any field being a match. This impairs readability in cases like this:

let thingy = Thingy {
   calc: big + calculation,
   redundant: redundant,
   other: stuff.into(),
};

As you can see, if you apply the suggestion, you end up with a weird line that is different from the rest. I suggest that the lint be split such that it distinguishes between "all fields are redundant" and "some fields are redundant".

Contributor guide

Tech stack
rust
Domain
developer experiencetooling
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.
1-2 days
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
Rust programmingClippy lint development basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50
Research direction
Examine the existing `redundant field names` lint implementation in the clippy source code. The current behavior triggers when any field matches. To implement the distinction, modify the lint to check each field individually and categorize whether some or all fields are redundant. This likely involves iterating over the struct fields and comparing names. The lint is in `clippy lints/src/`; find the relevant file and understand how lints are structured. Consider adding a new variant to the diagnostic message or splitting the lint into two separate categories. Review any comments or discussions in the issue for additional context.