Implement runBlockingNonInterruptible in tests and test it

Author: dkhalanskyjb

kotlinx-coroutines-core/jvm/test/RunBlockingJvmTest.kt

@@ -64,6 +64,27 @@ class RunBlockingJvmTest : TestBase() {
         finish(5)
     }
 
+    /**
+     * Tests that [runBlockingNonInterruptible] is going to run its job to completion even if it gets interrupted
+     * or if thread switches occur.
+     */
+    @Test
+    fun testNonInterruptibleRunBlocking() {
+        startInSeparateThreadAndInterrupt { mayInterrupt ->
+            val v = runBlockingNonInterruptible {
+                mayInterrupt()
+                repeat(10) {
+                    expect(it + 1)
+                    delay(1)
+                }
+                42
+            }
+            assertEquals(42, v)
+            expect(11)
+        }
+        finish(12)
+    }
+
     private fun startInSeparateThreadAndInterrupt(action: (mayInterrupt: () -> Unit) -> Unit) {
         val latch = CountDownLatch(1)
         val thread = thread {
@@ -73,4 +94,18 @@ class RunBlockingJvmTest : TestBase() {
         thread.interrupt()
         thread.join()
     }
+
+    private fun <T> runBlockingNonInterruptible(action: suspend () -> T): T {
+        val deferred = CompletableDeferred<T>()
+        try {
+            runBlocking {
+                withContext(NonCancellable) {
+                    deferred.completeWith(runCatching { action() })
+                }
+            }
+        } catch (_: InterruptedException) {
+            Thread.currentThread().interrupt() // restore the interrupted flag
+        }
+        return deferred.getCompleted()
+    }
 }