flush stdout after any printed test result

When running tests from wrappers, such as continuous integration servers, the output of tests may be incorrectly buffered that will result in truncated displaying of tests when failures occur. This behavior incorrectly identifies the wrong test as the failure point in the suites, enforcing a fflush of stdout ensures the buffer is correctly flushed after each marker point for testing.

Author: phausler

Sources/XCTest/XCTestCase.swift

@@ -11,6 +11,13 @@
 //  Base protocol (and extension with default methods) for test cases
 //
 
+#if os(Linux) || os(FreeBSD)
+import Glibc
+#else
+import Darwin
+#endif
+
+
 public protocol XCTestCase : XCTestCaseProvider {
     func setUp()
     func tearDown()
@@ -47,6 +54,7 @@ extension XCTestCase {
                 }
 
                 print("Test Case '\(method)' started.")
+                fflush(stdout)
 
                 setUp()
 
@@ -74,6 +82,7 @@ extension XCTestCase {
                 }
 
                 print("Test Case '\(method)' \(result) (\(printableStringForTimeInterval(duration)) seconds).")
+                fflush(stdout)
                 XCTAllRuns.append(XCTRun(duration: duration, method: method, passed: failures.count == 0, failures: failures))
                 XCTFailureHandler = nil
             }
@@ -89,6 +98,7 @@ extension XCTestCase {
         }
 
         print("Executed \(tests.count) test\(testCountSuffix), with \(totalFailures) failure\(failureSuffix) (\(unexpectedFailures) unexpected) in \(printableStringForTimeInterval(totalDuration)) (\(printableStringForTimeInterval(overallDuration))) seconds")
+        fflush(stdout)
     }
 
     public func setUp() {

Sources/XCTest/XCTestMain.swift

@@ -27,6 +27,7 @@ struct XCTFailure {
 
     func emit(method: String) {
         print("\(file):\(line): \(expected ? "" : "unexpected ")error: \(method) : \(failureDescription) - \(message)")
+        fflush(stdout)
     }
 }
 
@@ -63,6 +64,7 @@ internal struct XCTRun {
     }
 
     print("Total executed \(XCTAllRuns.count) test\(testCountSuffix), with \(totalFailures) failure\(failureSuffix) (\(totalUnexpectedFailures) unexpected) in \(printableStringForTimeInterval(totalDuration)) (\(printableStringForTimeInterval(overallDuration))) seconds")
+    fflush(stdout)
     exit(totalFailures > 0 ? 1 : 0)
 }