Incorrect ecmaVersion suggests only the old-style ES versions

[mgol]

Tell us about your environment

• ESLint Version: 3.8.1
• Node Version: 3.9.0
• npm Version: 3.10.8

What parser (default, Babel-ESLint, etc.) are you using?
default

Please show your full configuration:

'use strict';

module.exports = {
    parserOptions: {
        ecmaVersion: 2018,
    },
};

What did you do? Please include the actual source code causing the issue.

eslint .

What did you expect to happen?
An error message that would mention the 2015, 2016 & 2017 options.

What actually happened? Please include the actual, raw output from ESLint.
It prints:

Parsing error: ecmaVersion must be 3, 5, 6, 7, or 8

[not-an-aardvark]

Thanks, I can reproduce this. We should probably mention the 2015-2017 options as well, although I'm not sure of the best way to do that (something like 3, 5, 6, 7, 8, 2015, 2017, or 2017 might be confusing since some of the options will do the same thing).

[gyandeeps]

We are printing the error message coming from espree.
eslint/espree#300 will help us fix this issue.

[not-an-aardvark]

At the moment, ESLint modifies the version number here before sending it to espree, so we would have to make a change to that logic as well to avoid confusing errors (e.g. if ecmaVersion: 2018 was passed to ESLint, espree would return the error message for 9).

[mgol]

At the moment, ESLint modifies the version number here before sending it to espree

Is there any reason why this algorithm is so generic? I understand mapping 6 to 2015 and 7 to 2016 but why not use the years only going forward?

[nzakas]

I actually don't think we should be outputting the possible version numbers at all. It should be fine to just say "Invalid ecmaVersion", otherwise we'll be stuck updating that message every year.

And if this is coming from Espree, then it would have to be changed there, not here.

[sstern6]

@nzakas would like to take this on if that's ok.

Correct me if I am wrong, but looks like the error message needs to be changed in espree to "Invalid ecmaVersion", here.. https://github.com/eslint/espree/blob/master/espree.js#L126?

Thanks

[nzakas]

@sstern6 yes, you are correct.

[sstern6]

@nzakas thanks!

Should have a PR open for this late today PST and will ref this issue when I do.