This tests moveTo{Beginning, End}OfLineAndModifySelection. It should operate on line boundaries and not paragraph boundaries. To run it manually, click inside the first line of the editable region below and do Command+Shift+Left/Right Arrow, the selection should extend to the start/end of the line, not the start/end of the paragraph. Also, moveTo{Beginning, End}OfParagraphAndModifySelection should work.

The quick brown fox jumped over the lazy brown dog.