Add code coverage test for MD_FLAG_COLLAPSEWHITESPACE.
diff --git a/test/coverage.txt b/test/coverage.txt
index e8954c3..4b51ef6 100644
--- a/test/coverage.txt
+++ b/test/coverage.txt
@@ -199,3 +199,14 @@ main(int argc, char** argv)
return 0;
}
~~~
+
+
+## Flag `MD_FLAG_COLLAPSEWHITESPACE`
+
+```````````````````````````````` example
+foo bar → baz
+.
+<p>foo bar baz</p>
+.
+--fcollapse-whitespace
+````````````````````````````````