Proposal: Modes

Champions:

• @JakobJingleheimer

Authors:

• @JakobJingleheimer

Stage

Current: 0

The Problem

Code that needs to be conditionally executed in different contexts. This is currently hacked together with process.env.NODE_ENV (which doesn't exist outside of node et al); in a browser environment, that can't be used to affect the runtime's behaviour.

With a native flag, that could open the door for:

• Conditional code execution
  • Comparisons
  • Connecting to different external resources
  • Logging
• Special access that cannot be granted in a production context (Proxy, Constituents of expressions, Constituents of structure, Internal slots)

This could be broadly useful, in particular for the Comparisons and Inspector proposals.

PRODUCTION: if (!compare(a, b)) throw new Error('…');

NONPRODUCTION: inspect(b, { detectProxy: true });

The runtime would ensure "non-production" code cannot be executed in a production environment (such as limiting to localhost).