Drop Swift 6.0 (#642)

Author: fabianfett

.github/workflows/test.yml

@@ -20,9 +20,9 @@ jobs:
       fail-fast: false
       matrix:
         swift-image:
-          - swift:6.0-jammy
-          - swift:6.1-noble
+          - swift:6.1-jammy
           - swift:6.2-noble
+          - swift:6.3-noble
           - swiftlang/swift:nightly-main-noble
     container: ${{ matrix.swift-image }}
     runs-on: ubuntu-latest

Package.swift

@@ -1,19 +1,10 @@
-// swift-tools-version:6.0
+// swift-tools-version:6.1
 import PackageDescription
 
-#if compiler(>=6.1)
 let swiftSettings: [SwiftSetting] = [
     .enableUpcomingFeature("ExistentialAny"),
     .enableUpcomingFeature("NonisolatedNonsendingByDefault"),
 ]
-#else
-let swiftSettings: [SwiftSetting] = [
-    .enableUpcomingFeature("ExistentialAny"),
-    // Sadly the 6.0 compiler concurrency checker finds false positives.
-    // To be able to compile, lets reduce the language version down to 5 for 6.0 only.
-    .swiftLanguageMode(.v5),
-]
-#endif
 
 let package = Package(
     name: "postgres-nio",

Tests/PostgresNIOTests/New/Data/UUID+PSQLCodableTests.swift

@@ -81,7 +81,6 @@ import NIOCore
         }
     }
 
-    #if compiler(>=6.1)
     @Test func testDecodeFailureFromBytes() {
         let uuid = UUID()
         var buffer = ByteBuffer()
@@ -129,5 +128,4 @@ import NIOCore
             #expect(error == .typeMismatch)
         }
     }
-    #endif
 }

Tests/PostgresNIOTests/New/PostgresCellTests.swift

@@ -44,7 +44,6 @@ import NIOCore
             columnIndex: 1
         )
 
-        #if compiler(>=6.1)
         let error = #expect(throws: PostgresDecodingError.self) {
             try cell.decode(Int?.self, context: .default)
         }
@@ -62,26 +61,5 @@ import NIOCore
         #expect(correctType)
         #expect(error.postgresType == .text)
         #expect(error.postgresFormat == .binary)
-        #else
-        do {
-            _ = try cell.decode(Int?.self, context: .default)
-            Issue.record("Expected to throw")
-        } catch {
-            guard let error = error as? PostgresDecodingError else {
-                Issue.record("Expected error at this point")
-                return
-            }
-
-            #expect(error.file == #fileID)
-            #expect(error.line == #line - 9)
-            #expect(error.code == .typeMismatch)
-            #expect(error.columnName == "hello")
-            #expect(error.columnIndex == 1)
-            let correctType = error.targetType == Int?.self
-            #expect(correctType)
-            #expect(error.postgresType == .text)
-            #expect(error.postgresFormat == .binary)
-        }
-        #endif
     }
 }