sindresorhus/eslint-plugin-unicorn

Rule proposal: `no-useless-interpolation`

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#1,261 opened on May 11, 2021

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help wantednew rule

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Description

Hi there! 👋 First of all, thanks again for this plugin, super helpful, the things available in this plugin.

I wanted to propose a new rule to address a pattern that I have seen from a lot of our students at @upleveled - writing overly complex patterns with unnecessary interpolations in template strings (eg. a single string variable, or a string literal, or multiple string literals).

Fail

const withString = `${str}`;
const withStringLiteral = `${'abc'}`;
const withMultipleStringLiterals = `${'abc'}${'def'}`;

Pass

const withString = str;
const withStringLiteral = 'abc';
const withMultipleStringLiterals = 'abcdef';

Implementation ideas

Looking into the ASTExplorer, I guess the simple version of the first failure case below would be:

  • only 1 element in TemplateLiteral.expressions (an Identifier)
  • only 2 elements in TemplateLiteral.quasis, all empty strings

For the literals, I guess no limit to the quasis, but every element in expressions should be a Literal.

Contributor guide

Research direction
Create a new rule file in the rules directory, implement logic to detect template literals with a single expression that is an identifier or a literal string. Write corresponding tests and document the rule.
Tech stack
javascript
Domain
tooling
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
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.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JavaScript
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
85