naturalSelectionStrings.*Property.value is a build error

[pixelzoom]

In phetsims/natural-selection#319, I had to undo a whole bunch of work in Natural Selection, because calling naturalSelectionStrings.addMutationsProperty.value (for example) is a build error. All Properties in *Strings.ts are of type TReadOnlyProperty<string>, which includes get and get value() in its API. Why this is an error? Why is it not flagged until build?!? Aren't we trying to eliminate string instances from *Strings.ts eventually?

Also note that getting the value of a StringProperty indirectly, like in this example, is NOT a build error:

class Foo {
 constructor( stringProperty: TReadOnlyProperty<string> ) {
   console.log( stringProperty.value );
 }
}
new Foo( naturalSelectionStrings.addMutationsProperty );

The build error is:

Fatal error: Perennial task failed:
Error: no value for string: addMutations.value
at Object.getStringFromMap (/Users/cmalley/PhET/GitHub/chipper/js/common/ChipperStringUtils.js:148:15)

.. and occurs in getStringMap.js. Assigning to the author @jonathanolson.

High priority because for phetsims/natural-selection#319.

[samreid]

It thinks “value” is a nested string key. The workaround is to put const m = naturalSelectionString.addMutationsProperty on a separate line, then you can link to m. Someone at dev meeting proposed a long term fix, I think it’s assigned to
@jonathanolson.

[pixelzoom]

Thanks. I’ll wait for the longterm fix.

[samreid]

The general problem is described in phetsims/mean-share-and-balance#99, assigned to @jonathanolson

[pixelzoom]

My workaround in natural-selection ProportionsBarNode.js for phetsims/natural-selection#319:

//TODO https://github.com/phetsims/chipper/issues/1314 using these Properties inline causes a build error
const greaterThanValuePercentProperty = naturalSelectionStrings.greaterThanValuePercentStringProperty;
const lessThanValuePercentProperty = naturalSelectionStrings.lessThanValuePercentStringProperty;
const valuePercentProperty = naturalSelectionStrings.valuePercentStringProperty;

[jonathanolson]

Should be fixed above for common usages. @pixelzoom can you verify?

Also, I'd like to note that there are some degenerate examples that the current method will fail on, notably:

        // - joistStrings.someStringProperty[ 0 ]
        // - joistStrings.something[ 0 ]
        // - joistStrings.something[ 'length' ]

We'd need to remove our "error on something that looks like a string but isn't found" since there's no good way to filter these out (without looking for array indices, any method/property that can be on a string, etc.)

Tagging for dev meeting to see if this is acceptable (with a PSA).

[pixelzoom]

👍🏻 Confirmed by doing a build of natural-selection with things like naturalSelectionStrings.valuePercentStringProperty.value in the code. Closing.