function numberRadix - test 9 wrong

I would like to give some feedback about function numberRadix(str_number, radix)

Test 9/9 fails with correct result Your result: 738 is correct = 9 + 9*9^2 but test 9/9 fails Right result:-1 Fail:numberRadix("909",9)

Please check

From: https://js.checkio.org/mission/number-radix/solve/

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