[IC] Add unit tests for TransactionOutputsRegistrar

#KT-49785 In Progress

build-common/test/org/jetbrains/kotlin/incremental/TransactionOutputsRegistrarTest.kt

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.incremental
+
+import org.jetbrains.kotlin.build.report.DoNothingBuildReporter
+import org.jetbrains.kotlin.compilerRunner.OutputItemsCollector
+import org.junit.jupiter.api.Assertions.*
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.io.TempDir
+import java.io.File
+import java.nio.file.Files
+import java.nio.file.Path
+
+class TransactionOutputsRegistrarTest {
+    @TempDir
+    private lateinit var stashDir: Path
+
+    @TempDir
+    private lateinit var workingDir: Path
+
+    private class MockOutputItemsCollector : OutputItemsCollector {
+        val addedOutputItems = mutableSetOf<Pair<Collection<File>, File>>()
+
+        override fun add(sourceFiles: Collection<File>, outputFile: File) {
+            addedOutputItems.add(sourceFiles to outputFile)
+        }
+    }
+
+    @Test
+    fun testSuccessfulTransaction() {
+        val mockCollector = MockOutputItemsCollector()
+        val srcFile = workingDir.resolve("a.kt")
+        val outputFile = workingDir.resolve("AKt.class")
+        RecoverableCompilationTransaction(DoNothingBuildReporter, stashDir).use {
+            val registrar = TransactionOutputsRegistrar(it, mockCollector)
+            registrar.add(listOf(srcFile.toFile()), outputFile.toFile())
+            Files.write(outputFile, "blah-blah".toByteArray())
+            it.markAsSuccessful()
+        }
+        assertIterableEquals(
+            setOf(listOf(srcFile.toFile()) to outputFile.toFile()),
+            mockCollector.addedOutputItems,
+            "TransactionOutputsRegistrar should call the origin"
+        )
+        assertEquals("blah-blah", String(Files.readAllBytes(outputFile)))
+    }
+
+    @Test
+    fun testFailedTransaction() {
+        val mockCollector = MockOutputItemsCollector()
+        val srcFile = workingDir.resolve("a.kt")
+        val outputFile = workingDir.resolve("AKt.class")
+        RecoverableCompilationTransaction(DoNothingBuildReporter, stashDir).use {
+            val registrar = TransactionOutputsRegistrar(it, mockCollector)
+            registrar.add(listOf(srcFile.toFile()), outputFile.toFile())
+            Files.write(outputFile, "blah-blah".toByteArray())
+        }
+        assertIterableEquals(
+            setOf(listOf(srcFile.toFile()) to outputFile.toFile()),
+            mockCollector.addedOutputItems,
+            "TransactionOutputsRegistrar should call the origin"
+        )
+        assertFalse(Files.exists(outputFile), "Output file wasn't reverted")
+    }
+}