Why is the JavaScript crc-32 library, and the Java CRC32 class returning different results? Am I implementing it wrong?
const CRC32 = require('crc-32')
const input = "3b67b67f-673b-4f23-a023-3756f513d707:19.63865368:6ace080f-6f47-44fa-86f8-c278f5bb6f07:2.34121407:42dda603-8a36-4200-826c-80714a40b470:0.923498:1301a851-b77e-489f-beb8-c2b4ef349a90:0.08:bf077871-5709-4a84-b3a9-22bfa8313fa2:0.00382495:6341cbef-bccc-43af-8927-31be3f3cd2e9:1.24039659:aeef18c5-457c-41ca-abda-3940b151e410:0.02821:42943143-bb81-4993-8788-df3c434bce89:0.09:787ef6da-48ce-4bb5-978a-b0fdd9ce223a:0.07:c3850c7b-d0fa-4c2a-8c67-0405bee185da:0.50443922:06429537-15e7-465c-aafa-f9974fb20b95:0.48535755:978d18ba-ffe7-48a3-9642-0de57b249383:0.1:59de5468-be8c-4d56-ad1e-3425914fc081:0.35722062:b6eea705-651b-40db-9b01-e535150ab0f3:0.00408603:6cc9440e-d86b-475d-986e-b9076104873a:1.80178:7711fc0e-dc02-431f-90b8-fde7cd762ce0:0.00402297:58397c47-5cac-424c-9b2b-7dc50c703f6f:0.08"
CRC32.str(input)
# Result: -1990607021
import java.util.zip.CRC32
val input = "3b67b67f-673b-4f23-a023-3756f513d707:19.63865368:6ace080f-6f47-44fa-86f8-c278f5bb6f07:2.34121407:42dda603-8a36-4200-826c-80714a40b470:0.923498:1301a851-b77e-489f-beb8-c2b4ef349a90:0.08:bf077871-5709-4a84-b3a9-22bfa8313fa2:0.00382495:6341cbef-bccc-43af-8927-31be3f3cd2e9:1.24039659:aeef18c5-457c-41ca-abda-3940b151e410:0.02821:42943143-bb81-4993-8788-df3c434bce89:0.09:787ef6da-48ce-4bb5-978a-b0fdd9ce223a:0.07:c3850c7b-d0fa-4c2a-8c67-0405bee185da:0.50443922:06429537-15e7-465c-aafa-f9974fb20b95:0.48535755:978d18ba-ffe7-48a3-9642-0de57b249383:0.1:59de5468-be8c-4d56-ad1e-3425914fc081:0.35722062:b6eea705-651b-40db-9b01-e535150ab0f3:0.00408603:6cc9440e-d86b-475d-986e-b9076104873a:1.80178:7711fc0e-dc02-431f-90b8-fde7cd762ce0:0.00402297:58397c47-5cac-424c-9b2b-7dc50c703f6f:0.08"
val crC32 = CRC32()
crC32.update(input.toByteArray(Charsets.UTF_8))
crC32.value
# Result 2304360275
How do I make the Kotlin function return the same value as the JavaScript?
They're not different. They are both the exact same 32-bit value, in one case interpreted as an unsigned 32-bit integer, in the other interpreted as a two's complement signed 32-bit integer.
Just cast the Java long value to an int with (int), and you'll get the signed interpretation.