oven-sh/bun

Add "no default conditions" option to cli and build API

Open

#12204 opened on Jun 27, 2024

View on GitHub
 (1 comment) (0 reactions) (0 assignees)Rust (90,348 stars) (4,486 forks)batch import
enhancementgood first issue

Description

What is the problem this feature would solve?

In my app, I have a transitive dependency on a package which uses conditional exports to provide different behavior. Bun always resolves conditional exports using some default conditions (in my case the problematic one is "node") and exposes no API to remove these default conditions. Thus, I am unable to control which module I receive from the package.

What is the feature you are proposing to solve the problem?

I am proposing a new "no default conditions" option:

  • for the bun cli, a --no-default-conditions flag
  • for the bun build API, a noDefaultConditions property

This option would remove all default conditions, and only use the conditions specified using the conditions option: https://bun.sh/blog/bun-v1.0.30#new-flag-conditions. Alternatively, this option could simply remove "problematic" conditions like "node" and "worker", and only include 'default', 'module', 'import' and 'require' (but I'd prefer if I had 100% control).

What alternatives have you considered?

In my particular case, I can pass the "browser" condition to bun, because my package incidentally uses the "browser" condition with the module I want before the "node" condition. However, this is not a proper solution.

Contributor guide

Tech stack
nodejsjavascript
Domain
cliapi
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.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Basic understanding of BunFamiliarity with conditional exportsKnowledge of CLI and API design
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
The implementation should modify the CLI argument parser to accept a no default conditions flag, likely in src/cli.zig. Also, the build API should expose a noDefaultConditions property in the BuildOptions type. Examine the existing conditions flag implementation for guidance. Ensure that when noDefaultConditions is set, all default conditions are removed so only user specified conditions apply. Consider edge cases where conditions may be needed for platform detection. Test with a package that uses conditional exports to verify the behavior.