`Span` for `Expr::Case` does not include the heading and trailing keywords

[eliaperantoni]

How to reproduce

1. Build a Expr::Case expression, e.g.:

CASE col1 WHEN col2 THEN col3 ELSE col4 END

2. Call Spanned:span on it.

You'll notice that the Span only selects nodes that appear within the CASE and implement Spanned correctly, but the CASE and END keywords are not highlighted.

CASE col1 WHEN col2 THEN col3 ELSE col4 END
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     Span covers this

Expected behavior

The Span should include CASE and END too:

CASE col1 WHEN col2 THEN col3 ELSE col4 END
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Span should cover this

[eliaperantoni]

Fixed in #1874

[eliaperantoni]

@alamb should be added to tracker ticket #1548 so people can find this and the related PR for inspiration

[alamb]

@alamb should be added to tracker ticket #1548 so people can find this and the related PR for inspiration

Done!