StreamToLoop tests grouped

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamToLoop/beforeReduce.java

@@ -0,0 +1,39 @@
+// "Fix all 'Stream API call chain can be replaced with loop' problems in file" "true"
+
+import java.util.List;
+import java.util.Optional;
+import java.util.OptionalInt;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+import static java.util.Arrays.asList;
+
+public class Main {
+  public static String testReduce2(List<String> list) {
+    return list.stream().re<caret>duce("", (a, b) -> a+b);
+  }
+
+  public static int testReduce3(List<String> list) {
+    return list.stream().reduce(0, (a, b) -> a+b.length(), Integer::sum);
+  }
+
+  private static Integer testReduceMethodRef(List<Integer> numbers) {
+    return numbers.stream().reduce(0, Math::max);
+  }
+
+  private static OptionalInt testReduceOptionalInt() {
+    return IntStream.of().reduce((a, b) -> a*b);
+  }
+
+  private static Optional<Integer> testReduceOptionalInteger(Integer... numbers) {
+    return Stream.of(numbers).reduce((a, b) -> a*b);
+  }
+
+  public static void main(String[] args) {
+    System.out.println(testReduce2(asList("a", "b", "c")));
+    System.out.println(testReduce3(asList("a", "b", "c")));
+    testReduceMethodRef(asList(1, 10, 5));
+    System.out.println(testReduceOptionalInt());
+    System.out.println(testReduceOptionalInteger(1,2,3,4));
+  }
+}