expected and actual were inverted. That's corrected.

for php : $this->assertEquals(duplicate_encode(' ( ( )'), ')))))(');
Failed asserting that two strings are equal.
Expected: '(((((('
Actual : ')))))('

Looks like test doesn't work correctly or some details were missed in description

For PHP
testBasicTests
✘ Failed asserting that two strings are equal.
Expected: 'c)((w())())'
Actual : '()(((())())'

testSomeRandoms
✘ Failed asserting that two strings are equal.
Expected: 'p((j()o(nv)((hwc(((('
Actual : '((((()(((()()((()((('

Are those tests results strange only for me?