Incorrect docs for string interpolation

[mjbcopland]

String interpolation does not strip whitespace from values or modifiers. This isn't necessarily a bug but is not clarified anywhere and does mean that the docs are wrong.

Deriving a reproduction from transform-cache's cache key example which should interpolate the current date:

cacheKey: user-{args.id}-{yyyy-mm-dd | date}

We can see that the output is not as expected.

> stringInterpolator.parse("{yyyy-mm-dd | date}")
''

This is because there is whitespace in the modifier name which we can demonstrate by registering a modifier with that whitespace.

> stringInterpolator.registerModifier(" date", () => "Oops!")
Interpolator {}
> stringInterpolator.parse("{yyyy-mm-dd | date}"));
'Oops!'

The correct behaviour is to remove the whitespace from the interpolation template.

> stringInterpolator.parse("{yyyy-mm-dd|date}")
'2021-24-22'

[ardatan]

We'd love to accept a PR for this change :)

[Urigo]

At the bottom of each page there should be an "Edit this page" button so get you into changing the docs!