I think the problem is here:
[contains(text()='Some text')]
To break this down,
[] are a conditional that operates on each individual node in
that node set -- each span node in your case. It matches if any of the individual nodes it operates
on match the conditions inside the brackets. text() is a selector
that matches all of the text nodes that are children of the context
node -- it returns a node set. contains is a function that operates
on a string. If it is passed a node set, the node set is converted
into a string by returning the string-value of the node in the
node-set that is first in document order.You should try to change this to
[text()[contains(.,'Some text')]]
The outer [] are a conditional that operates on each individual node
in that node set text() is a selector that matches all of the text
nodes that are children of the context node -- it returns a node
set.
The inner [] are a conditional that operates on each node in that
node set.
contains is a function that operates on a string. Here it is passed
an individual text node (.).