ES3 is a poor default for typescript

Search Terms

defaults, ecmascript

Suggestion

The latest available typescript typescript@3.7.2 produces a bunch of unnecessary errors by targeting a very old version of JavaScript:

Error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.

Typescript should update the default language version to something more reasonable.

Use Cases

A user install typescript. They compile a project using tsc which will fail in most cases. The users discovers that TypeScript targets a 21 year old version of JavaScript by default. They update their compiler options to support and 11 year old version of JavaScript at minimum.

Examples

tsc somefile.ts working without errors.

Checklist

My suggestion meets these guidelines:

• This wouldn’t be a breaking change in existing TypeScript/JavaScript code
• This wouldn’t change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn’t a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript’s Design Goals.

[mikemaccana]

Just a note that I’m unsubscribing from this bug as I’m tired of the sarcasm and trolling.

[RyanCavanaugh]

A few points

• Inconvenience or annoyance doesn’t clearly outweigh someone else’s runtime behavior getting broken during a compiler update. The asymmetry of impact here is very large.
• The set of users who would get hurt worst by this aren’t the ones who are reading the issue tracker
• We really, really think everyone should be using a tsconfig.json at this point, and tsc --init does default to ES5
• I don’t think this will never change, but we’d probably do an all-at-once update to all of the default commandline options at some point (moduleResolution, strictFunctionTypes, strictNullChecks, and a few others come to mind as things that should have different defaults “in the future”). Maybe once every 10 years would be a reasonable cadence for that (TypeScript 5.0?)
• Twitter polls about what people are choosing to currently target is not what’s under consideration here. A poll from the original position would be “Do you want to have your program break during some future compiler update so that someone else feels less inconvenienced about the no-config-file behavior of TypeScript?” which I think would have very different results.