Fix slow failing test (#57)

Author: czechboy0

Tests/AsyncDNSResolverTests/c-ares/CAresDNSResolverTests.swift

@@ -122,79 +122,95 @@ final class CAresDNSResolverTests: XCTestCase {
     }
 
     func test_concurrency() async throws {
+        let verbose = self.verbose
+
         func run(
+            _ name: String,
             times: Int = 100,
             _ query: @Sendable @escaping (_ index: Int) async throws -> Void
         ) async throws {
-            try await withThrowingTaskGroup(of: Void.self) { group in
-                for i in 1...times {
-                    group.addTask {
-                        try await query(i)
+            let start = Date.now
+            defer {
+                if verbose {
+                    print("Test of \(name) took \(Int64(start.timeIntervalSinceNow * -1000)) ms.")
+                }
+            }
+            do {
+                try await withThrowingTaskGroup(of: Void.self) { group in
+                    for i in 1...times {
+                        group.addTask {
+                            try await query(i)
+                        }
                     }
+                    for try await _ in group {}
+                }
+            } catch {
+                if verbose {
+                    print("Test of \(name) is throwing an error.")
                 }
-                for try await _ in group {}
+                throw error
             }
         }
 
         let resolver = self.resolver!
-        let verbose = self.verbose
-        try await run { i in
+        try await run("queryA") { i in
             let reply = try await resolver.queryA(name: "apple.com")
             if verbose {
                 print("[A] run #\(i) result: \(reply)")
             }
         }
 
-        try await run { i in
+        try await run("queryAAAA") { i in
             let reply = try await resolver.queryAAAA(name: "apple.com")
             if verbose {
                 print("[AAAA] run #\(i) result: \(reply)")
             }
         }
 
-        try await run { i in
+        try await run("queryNS") { i in
             let reply = try await resolver.queryNS(name: "apple.com")
             if verbose {
                 print("[NS] run #\(i) result: \(reply)")
             }
         }
 
-        try await run { i in
+        try await run("queryCNAME") { i in
             let reply = try await resolver.queryCNAME(name: "www.apple.com")
             if verbose {
                 print("[CNAME] run #\(i) result: \(String(describing: reply))")
             }
         }
 
-        try await run { i in
+        try await run("querySOA") { i in
             let reply = try await resolver.querySOA(name: "apple.com")
             if verbose {
                 print("[SOA] run #\(i) result: \(String(describing: reply))")
             }
         }
 
-        try await run { i in
+        try await run("queryPTR") { i in
             let reply = try await resolver.queryPTR(name: "47.224.172.17.in-addr.arpa")
             if verbose {
                 print("[PTR] run #\(i) result: \(reply)")
             }
         }
 
-        try await run { i in
+        try await run("queryMX") { i in
             let reply = try await resolver.queryMX(name: "apple.com")
             if verbose {
                 print("[MX] run #\(i) result: \(reply)")
             }
         }
 
-        try await run { i in
+        // TXT lookups are very slow in CI and lead to timeouts.
+        try await run("queryTXT", times: 5) { i in
             let reply = try await resolver.queryTXT(name: "apple.com")
             if verbose {
                 print("[TXT] run #\(i) result: \(reply)")
             }
         }
 
-        try await run { i in
+        try await run("querySRV") { i in
             let reply = try await resolver.querySRV(name: "_caldavs._tcp.google.com")
             if verbose {
                 print("[SRV] run #\(i) result: \(reply)")