react / react/metro

Passing path to .babelrc as a packager option (programmatic and CLI)

Open
#24 1 comment 6 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
JavaScript
Stars
5.6k
Forks
696
Avg merge
8m
Merged PRs (30d)
7

Description

In the transformer there's this comment referring to the .babelrc lookup:

// In the future let's look into adding a command line option to specify
// this location.

https://github.com/facebook/metro-bundler/blob/master/packages/metro-bundler/src/transformer.js#L54

At Expo we use a different .babelrc internally (for monorepo reasons) than in our OSS repos so being able to specify a different .babelrc without having to fork the default transformer is helpful. I was going to work on a PR for this, is this still a feature you'd want? I was thinking it'd probably be a CLI option like --babelrc and programmatic option like babelRCPath that gets passed through to the transformer.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with packages/metro-bundler/src/transformer.js at the .babelrc lookup comment, then trace how packager options reach the transformer from the CLI and programmatic API. The work is done when both interfaces accept a custom .babelrc path and use it for transformation without requiring a fork of the default transformer.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript
Domain
build-system, cli
Issue type
Feature
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
38/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.