TC39 Process

The TC39 Process explains the various stages of a desired feature until it becomes adopted and included in the language.

Without going into the specifics of the process, what is helpful to know is the various stages a new feature goes through...

Stage 0 "Strawman"

This is the very first stage, it's a crude starting point and it's not expected to be anywhere near final.

Stage 1 "Proposal"

At this point you could expect to see some demos/use cases start to be described. The syntax is expected to change, but this is considered a feature worth spending time on.

Stage 2 "Draft"

This is the where the proposal needs a draft covering the semantics of the feature. If a feature makes it this far, it's fair to assume it will eventually be standardized.

Stage 3 "Candidate"

At this point, semantics & syntax are completely laid out and the current spec text would've been signed off by the ECMAScript editor.

Stage 4 "Finished"

It's in the field and there's at least 2 implementations, it will get included in the next ECMAScript revision.

Current TC39 proposals can be viewed on GitHub

For example, the proposal for the String.prototype.padStart & String.prototype.padEnd implementation.