1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
import Foundation
struct RedirectChainService {
static func trace(domain: String) async -> ServiceResult<[RedirectHop]> {
do {
let hops = try await followChain(startingURL: URL(string: "https://\(domain)")!)
return hops.isEmpty ? .empty("No redirect data available") : .success(hops)
} catch {
do {
let hops = try await followChain(startingURL: URL(string: "http://\(domain)")!)
return hops.isEmpty ? .empty("No redirect data available") : .success(hops)
} catch {
return .error(error.localizedDescription)
}
}
}
private static func followChain(startingURL: URL) async throws -> [RedirectHop] {
let delegate = NoRedirectDelegate()
let session = URLSession(
configuration: .ephemeral,
delegate: delegate,
delegateQueue: nil
)
defer { session.invalidateAndCancel() }
var hops: [RedirectHop] = []
var currentURL = startingURL
let maxRedirects = 10
for step in 1...maxRedirects + 1 {
var request = URLRequest(url: currentURL, timeoutInterval: 10)
request.httpMethod = "GET"
let (_, response) = try await session.data(for: request)
guard let httpResponse = response as? HTTPURLResponse else {
throw URLError(.badServerResponse)
}
let statusCode = httpResponse.statusCode
let isRedirect = (300...399).contains(statusCode)
if isRedirect, let location = httpResponse.value(forHTTPHeaderField: "Location") {
hops.append(RedirectHop(
stepNumber: step,
statusCode: statusCode,
url: currentURL.absoluteString,
isFinal: false
))
// Resolve relative redirects
if let nextURL = URL(string: location, relativeTo: currentURL)?.absoluteURL {
currentURL = nextURL
} else {
break
}
if step > maxRedirects { break }
} else {
// Non-redirect — this is the final destination
hops.append(RedirectHop(
stepNumber: step,
statusCode: statusCode,
url: currentURL.absoluteString,
isFinal: true
))
break
}
}
return hops
}
}
private final class NoRedirectDelegate: NSObject, URLSessionTaskDelegate, @unchecked Sendable {
func urlSession(
_ _: URLSession,
task _: URLSessionTask,
willPerformHTTPRedirection _: HTTPURLResponse,
newRequest _: URLRequest,
completionHandler: @escaping (URLRequest?) -> Void
) {
// Don't follow redirects automatically — return nil to stop
completionHandler(nil)
}
}
|
