SONARJAVA-5552 Fix FN in S1943 on method references. (#5143)

Author: tomasz-tylenda-sonarsource

its/autoscan/src/test/resources/autoscan/diffs/diff_S1874.json

@@ -1,6 +1,6 @@
 {
   "ruleKey": "S1874",
   "hasTruePositives": true,
-  "falseNegatives": 257,
+  "falseNegatives": 258,
   "falsePositives": 0
 }

java-checks-test-sources/default/src/main/java/checks/DefaultEncodingUsageCheckSample.java

@@ -1,5 +1,6 @@
 package checks;
 
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileReader;
 import java.io.FileWriter;
@@ -15,7 +16,9 @@
 import java.nio.charset.StandardCharsets;
 import java.util.Collection;
 import java.util.Formatter;
+import java.util.Optional;
 import java.util.Scanner;
+import java.util.stream.Stream;
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;
 import org.checkerframework.common.reflection.qual.UnknownClass;
@@ -149,5 +152,38 @@ void commons_fileutils_with_null(File file, CharSequence charSequence) throws IO
     FileUtils.writeStringToFile(file, "data", (java.nio.charset.Charset) null); // Noncompliant
   }
 
+  static class MethodReferences {
+    void usageOfConstructorReference(String resourcePath) throws IOException {
+      try (InputStream is = MethodReferences.class.getResourceAsStream(resourcePath)) {
+        Optional.ofNullable(is)
+          .map(InputStreamReader::new) // Noncompliant {{Remove this reference.}}
+//                                ^^^
+          .map(reader -> reader.hashCode() + 1);
+      }
+    }
 
+    String usageOfMethodReference(checks.File file) throws Exception {
+      return myMap(FileUtils::readFileToString, file); // Noncompliant {{Remove this reference.}}
+//                            ^^^^^^^^^^^^^^^^
+    }
+
+    // We need an interface for FileUtils::readFileToString that allows throwing an exception.
+    interface IOFunction<T, R> {
+      R apply(T input) throws IOException;
+    }
+
+    String myMap(IOFunction<checks.File, String> mapper, checks.File file) throws IOException {
+      return mapper.apply(file);
+    }
+
+    Optional<String> goodExamples() {
+      return Optional.of("good")
+        .map(String::new) // Compliant
+        .map(String::toUpperCase); // Compliant
+    }
+
+    Stream<ByteArrayOutputStream> goodBaos() {
+      return Stream.generate(ByteArrayOutputStream::new); // Compliant
+    }
+  }
 }

java-checks/src/main/java/org/sonar/java/checks/DefaultEncodingUsageCheck.java

@@ -31,6 +31,7 @@
 import org.sonar.plugins.java.api.tree.Arguments;
 import org.sonar.plugins.java.api.tree.ExpressionTree;
 import org.sonar.plugins.java.api.tree.MethodInvocationTree;
+import org.sonar.plugins.java.api.tree.MethodReferenceTree;
 import org.sonar.plugins.java.api.tree.NewClassTree;
 import org.sonar.plugins.java.api.tree.Tree;
 import org.sonar.plugins.java.api.tree.TypeCastTree;
@@ -130,11 +131,6 @@ public boolean isCompatibleWithJavaVersion(JavaVersion version) {
     return version.isSet() && version.asInt() < 18;
   }
 
-  @Override
-  public List<Tree.Kind> nodesToVisit() {
-    return Arrays.asList(Tree.Kind.METHOD_INVOCATION, Tree.Kind.NEW_CLASS);
-  }
-
   @Override
   protected MethodMatchers getMethodInvocationMatchers() {
     ArrayList<MethodMatchers> matchers = new ArrayList<>(Arrays.asList(
@@ -209,6 +205,11 @@ protected void onMethodInvocationFound(MethodInvocationTree mit) {
     }
   }
 
+  @Override
+  protected void onMethodReferenceFound(MethodReferenceTree methodReferenceTree) {
+    reportIssue(methodReferenceTree.method(), "Remove this reference.");
+  }
+
   private void testNullLiteralPassedForEncoding(ExpressionTree argument) {
     if (isNullLiteral(argument)) {
       reportIssue(argument, "Replace this \"null\" with actual charset.");