Remove tests that are not compatible with old Swift versions when needed

Author: Frizlab

Tests/JSONLoggerTests/JSONLoggerTests.swift

@@ -69,6 +69,7 @@ final class JSONLoggerTests : XCTestCase {
 		XCTAssertEqual(data.first, 0x0a)
 	}
 
+#if swift(>=5.7)
 	func testEncodeMetadataAsJSON() throws {
 		struct BestStruct : Encodable, CustomStringConvertible {
 			var val: Int
@@ -87,6 +88,7 @@ final class JSONLoggerTests : XCTestCase {
 		line.date = ref.date
 		XCTAssertEqual(line, ref)
 	}
+#endif
 
 	func testFallbackOnLogLineEncodeFailure() throws {
 		struct BestStruct : Encodable, CustomStringConvertible {

Tests/LinuxMain.swift

@@ -5,16 +5,23 @@ import XCTest
 
 
 
+let testWhenAvailable1: [(String, (XCTestCase) -> () -> Void)]
+#if swift(>=5.7)
+testWhenAvailable1 = [
+	("testEncodeMetadataAsJSON", JSONLoggerTests.testEncodeMetadataAsJSON),
+]
+#else
+testWhenAvailable1 = []
+#endif
 var tests: [XCTestCaseEntry] = [
 	testCase([
 		("test0NoSeparatorForFirstLog", JSONLoggerTests.test0NoSeparatorForFirstLog),
 		("testFromDoc", JSONLoggerTests.testFromDoc),
 		("testSeparatorForNotFirstLog", JSONLoggerTests.testSeparatorForNotFirstLog),
-		("testEncodeMetadataAsJSON", JSONLoggerTests.testEncodeMetadataAsJSON),
 		("testFallbackOnLogLineEncodeFailure", JSONLoggerTests.testFallbackOnLogLineEncodeFailure),
 		("testDecodeLogLineWithBothValidDateAndMangledDate", JSONLoggerTests.testDecodeLogLineWithBothValidDateAndMangledDate),
 		("testDecodeLogLineWithBothInvalidDateAndMangledDate", JSONLoggerTests.testDecodeLogLineWithBothInvalidDateAndMangledDate),
-	]),
+	] + testWhenAvailable1),
 ]
 #if !os(WASI)
 XCTMain(tests)