IDEA-163627 Simplify optional.isPresent() inspection could better handle some specific cases

IDEA-163462 Simplify Optional.isPresent() ? Optional.get() : ...

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/afterFindFirstOptional.java

@@ -0,0 +1,17 @@
+// "Replace with findFirst()" "true"
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+
+public class Main {
+  private static String test(List<String> list) {
+      Optional<String> found = list.stream().filter(Objects::nonNull).findFirst();
+      return found.orElse(null);
+  }
+
+  public static void main(String[] args) {
+    System.out.println(test(Arrays.asList(null, null, "aa", "bbb", "c", null, "dd")));
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/afterFindFirstOptionalFlatMap.java

@@ -0,0 +1,15 @@
+// "Replace with findFirst()" "true"
+
+import java.util.List;
+import java.util.Optional;
+
+public class Main {
+  public Optional<String> trim(String s) {
+    return s.isEmpty() ? Optional.empty() : Optional.of(s.trim());
+  }
+
+  public Optional<String> test(List<Object> objects) {
+      Optional<String> result = objects.stream().filter(obj -> obj instanceof String).findFirst().flatMap(obj -> trim((String) obj));
+      return result;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/beforeFindFirstOptional.java

@@ -0,0 +1,23 @@
+// "Replace with findFirst()" "true"
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+
+public class Main {
+  private static String test(List<String> list) {
+    Optional<String> found = Optional.empty();
+    for (String s : li<caret>st) {
+      if (Objects.nonNull(s)) {
+        found = Optional.of(s);
+        break;
+      }
+    }
+    return found.orElse(null);
+  }
+
+  public static void main(String[] args) {
+    System.out.println(test(Arrays.asList(null, null, "aa", "bbb", "c", null, "dd")));
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/beforeFindFirstOptionalFlatMap.java

@@ -0,0 +1,21 @@
+// "Replace with findFirst()" "true"
+
+import java.util.List;
+import java.util.Optional;
+
+public class Main {
+  public Optional<String> trim(String s) {
+    return s.isEmpty() ? Optional.empty() : Optional.of(s.trim());
+  }
+
+  public Optional<String> test(List<Object> objects) {
+    Optional<String> result = Optional.empty();
+    for(Object obj : obj<caret>ects) {
+      if(obj instanceof String) {
+        result = trim((String)obj);
+        break;
+      }
+    }
+    return result;
+  }
+}