StreamToLoop tests grouped

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

@@ -0,0 +1,71 @@
+// "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) {
+      String acc = "";
+      for (String s : list) {
+          acc = acc + s;
+      }
+      return acc;
+  }
+
+  public static int testReduce3(List<String> list) {
+      Integer acc = 0;
+      for (String s : list) {
+          acc = acc + s.length();
+      }
+      return acc;
+  }
+
+  private static Integer testReduceMethodRef(List<Integer> numbers) {
+      Integer acc = 0;
+      for (Integer number : numbers) {
+          acc = Math.max(acc, number);
+      }
+      return acc;
+  }
+
+  private static OptionalInt testReduceOptionalInt() {
+      boolean seen = false;
+      int acc = 0;
+      for (int i : new int[]{}) {
+          if (!seen) {
+              seen = true;
+              acc = i;
+          } else {
+              acc = acc * i;
+          }
+      }
+      return seen ? OptionalInt.of(acc) : OptionalInt.empty();
+  }
+
+  private static Optional<Integer> testReduceOptionalInteger(Integer... numbers) {
+      boolean seen = false;
+      Integer acc = null;
+      for (Integer number : numbers) {
+          if (!seen) {
+              seen = true;
+              acc = number;
+          } else {
+              acc = acc * number;
+          }
+      }
+      return seen ? Optional.of(acc) : Optional.empty();
+  }
+
+  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));
+  }
+}