add ProjectionDefinition.title from wkt.AUTHORITY

[ftoromanoff]

Following the DefinitelyTyped/types/proj4 (https://github.com/DefinitelyTyped/DefinitelyTyped/blob/72db0783554789ef424e5dc5a207a028c2a0169f/types/proj4/index.d.ts)
title in ProjectionDefinition should be mandatory but is nowhere to be found in index.cleanWKT().
I just added the fact that in cas ther is an AUTHORITY defined in the wkt that we use this information as title (parsed as a string).

In case i'm not posting in the right place, or i'm not following the way it should be, fell free to tell me where and what I should do.

Thanks

[ahocevar]

This file is auto-built, you should not be making changes to it. We'll need to make this clear in the README and/or with a proper .gitignore.

[ahocevar]

Also, I don't think it makes sense to change the library to match its 3rd party type definition. It should be the other way around. Which means @types/proj4 should be changed to match what we have here.

I could be convinced otherwise if there is a strong argument for having a title that shows the authority. I can't find one myself.

[ftoromanoff]

Based on the 3rd party type definition title was the only obligatory property, thus It was the only one on wich I could relied as an existing id, And follwing EPSG.io, I fell like title in format 'EPSG:XXXX' seemed like a good identifier.

What property should I use to id a specifique parsed wkt ?

[ahocevar]

The @types/proj4 types tell fairy tales. title is neither used for wkt nor for proj definitions in proj4js. If you're using wkt-parser standalone, name at the root level is what you should be looking at. As far as I know, the AUTHORITY entry is not mandatory in the WKT v1 spec, so your pull request would cause errors for wkt defs that don't contain one.

[ftoromanoff]

Thanks for the clarification about the @types/proj4.
I was using the name field but to avoid doublon between a proj.def defined through it's name and the same one defined using EPSG:XXXX, i thought about trying to get a more unique identifier.

Just to clarify I don't understand how my PR would cause errors as it's only if there is an AUTHORITY field that i set the property title from it.

[ahocevar]

It would cause errors or at least unexpected output if what you're putting in the title string is not available. So I'd prefer something like

if (wkt.AUTHORITY) {
  var authority = Object.keys(wkt.AUTHORITY)[0];
  if (authority && authority in wkt.AUTHORITY) {
    wkt.title = `${authority}:${wkt.AUTHORITY[authority]}`;
  }
}

[ftoromanoff]

I added what you suggested to avoid the case with an empty wkt.AUTHORITY.

[ahocevar]

Thanks, @ftoromanoff