Add suggested conversions between v1 and v2 basemap style enumerations

[gowin20]

Describe the problem

The new Basemap Styles Service v2 uses different basemap enumerations than version 1, and it is confusing. I think that users who are acustomed to v1 enumerations (e.g. ArcGIS:Imagery:Base) will be confused when their enumeration does not work with the new service (which expects arcgis/imagery/base to load the equivalent layer).

Describe the proposed solution

I would like to include a suggestion in the error message that displays when a v2 basemap is created using a v1 enumeration, and vice versa. The error message would read like the following:

Error: 'ArcGIS:Streets' is a v1 basemap style enumeration. Did you mean 'arcgis/streets'?

I have already written code that generates suggestions for the v2 service:

    const firstBreak = sourceAndStyle.indexOf(':');
    let secondBreak = sourceAndStyle.indexOf(':', firstBreak + 1);

    const source = sourceAndStyle.substring(0, firstBreak);
    const layer = (secondBreak !== -1) ? sourceAndStyle.substring(secondBreak + 1, sourceAndStyle.length) : null;

    if (secondBreak === -1) secondBreak = sourceAndStyle.length;
    const style = sourceAndStyle.substring(firstBreak + 1, secondBreak);

    const suggestion = source.toLowerCase() + '/' + style.toLowerCase() + (layer !== null ? '/' + layer.toLowerCase() : '');

However, providing a suggestion like this only makes sense if the original enumeration was valid. To check this, we would need to keep a static list of all valid basemap enumerations. This would obviously come with some overhead, so I'd like some feedback on whether or not this is reasonable

Alternatives considered

A self-describing endpoint is in the works for the v2 service that should return a json list of every supported basemap enumeration. It will not release for a while, but once it does we could deprecate our static list of enums in favor of this new endpoint. Luke Smallwood knows more.

Additional Information

No response