Next to the diff-ui section of the SourceTree application there is a gear icon that shows the difference in the files, you can click on it and set it to show whitespace or ignore whitespace !! I worked on the Internet for many hours and finally got a response after searching for the sourceTree equivalent of the git command:
Git version <= 1.8.3.4: git diff --ignore-space-at-eol -b -w [commit] ... Git version >= 1.8.4: git diff --ignore-space-at-eol -b -w --ignore-blank-lines [commit] ... See the options definition below: --ignore-space-at-eol Ignore changes in whitespace at EOL. -b --ignore-space-change Ignore changes in amount of whitespace. This ignores whitespace at line end, and considers all other sequences of one or more whitespace characters to be equivalent. -w --ignore-all-space Ignore whitespace when comparing lines. This ignores differences even if one line has whitespace where the other line has none. [git version 1.8.4+]--ignore-blank-lines Ignore changes whose lines are all blank.

Literature:
git command equivalent
Source tree file settings
source share