There are no sample tests or random tests.

Random tests only report XCTAssertTrue failed -, which is unacceptable (what is the expected and actual value?)

Tests are missing key components:

main.swift:50:35: error: cannot find 'result' in scope
             ["#", "#", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:55:35: error: cannot find 'result' in scope
             ["#", "#", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:60:35: error: cannot find 'result' in scope
             ["#", "O", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:65:35: error: cannot find 'result' in scope
             ["#", "#", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:72:35: error: cannot find 'result' in scope
             ["#", "#", "#"]]) == result(.draw))
                                  ^~~~~~
main.swift:77:35: error: cannot find 'result' in scope
             ["#", "#", "#"]]) == result(.draw))
                                  ^~~~~~
main.swift:82:35: error: cannot find 'result' in scope
             ["#", "#", "O"]]) == result(.draw))
                                  ^~~~~~
main.swift:87:35: error: cannot find 'result' in scope
             ["O", "#", "#"]]) == result(.draw))
                                  ^~~~~~
main.swift:94:35: error: cannot find 'result' in scope
             ["#", "#", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:99:35: error: cannot find 'result' in scope
             ["#", "#", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:104:35: error: cannot find 'result' in scope
             ["#", "#", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:109:35: error: cannot find 'result' in scope
             ["#", "#", "X"]]) == result(.wonX))
                                  ^~~~~~
main.swift:114:35: error: cannot find 'result' in scope
             ["#", "O", "X"]]) == result(.wonX))
                                  ^~~~~~
main.swift:119:35: error: cannot find 'result' in scope
             ["X", "O", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:124:35: error: cannot find 'result' in scope
             ["X", "#", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:129:35: error: cannot find 'result' in scope
             ["#", "#", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:136:35: error: cannot find 'result' in scope
             ["#", "#", "#"]]) == result(.draw))
                                  ^~~~~~
main.swift:146:35: error: cannot find 'result' in scope
             ["O", "#", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:152:35: error: cannot find 'result' in scope
             ["O", "#", "X"]]) == result(.wonX))
                                  ^~~~~~
main.swift:158:35: error: cannot find 'result' in scope
             ["#", "#", "X"]]) == result(.wonO))
                                  ^~~~~~
main.swift:164:35: error: cannot find 'result' in scope
             ["X", "#", "#"]]) == result(.draw))
                                  ^~~~~~
main.swift:170:35: error: cannot find 'result' in scope
             ["O", "#", "X"]]) == result(.wonX))
                                  ^~~~~~
main.swift:176:35: error: cannot find 'result' in scope
             ["O", "X", "#"]]) == result(.draw))
                                  ^~~~~~
main.swift:186:35: error: cannot find 'result' in scope
             ["O", "#", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:192:35: error: cannot find 'result' in scope
             ["O", "#", "X"]]) == result(.wonO))
                                  ^~~~~~
main.swift:198:35: error: cannot find 'result' in scope
             ["X", "#", "#"]]) == result(.wonX))
                                  ^~~~~~
main.swift:204:35: error: cannot find 'result' in scope
             ["X", "#", "#"]]) == result(.wonO))
                                  ^~~~~~
main.swift:215:35: error: cannot find 'result' in scope
             ["O", "X", "X"]]) == result(.draw))
                                  ^~~~~~
main.swift:229:35: error: cannot find 'result' in scope
             ["#", "#", "X"]]) == result(.wonX))
                                  ^~~~~~

Duplicate.

Sample tests missing

In addition to adding sample test cases, you should add some random tests to the main test suite to keep people from just submitting special case solutions for the fixed inputs.

Also, adding a variant for Swift 4 would be very welcome.

You have no sample tests at the moment, all you have is the default test that always passes if the submitted code compiles. You should really add your current test cases to the sample tests so people attempting the problem have something to work with (though you may want to save the empty input string for the hidden tests).

Prime sieve is a duplicate to many existing katas.

Needs random tests