SONARJAVA-5184 S5411 Suppress boxed Boolean warnings on @nonnull para…

…meters. (#4931)

Co-authored-by: leonardo-pilastri-sonarsource <[email protected]>

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

@@ -1,5 +1,7 @@
 package checks;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Optional;
 import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
@@ -725,4 +727,52 @@ void testBoxedValue(Boolean value) {
     }
   }
 
+  // Allow suppressing warnings caused by generic parameters,
+  // see SONARJAVA-5184.
+  public void lambdaParameterAnnotations() {
+    List<Boolean> xs = new ArrayList<>();
+    xs.add(true);
+
+    xs.forEach(b -> {
+      if (b) { // Noncompliant
+        foo();
+      } else {
+        bar();
+      }
+    });
+
+    xs.forEach((Boolean b) -> {
+      if (b) { // Noncompliant
+        foo();
+      } else {
+        bar();
+      }
+    });
+
+    xs.forEach((@NonNull Boolean b) -> {
+      if (b) {
+        foo();
+      } else {
+        bar();
+      }
+    });
+
+    // Suppressing warnings on @NonNull Booleans works too and we like it.
+
+    Boolean badBoolean = getSurprizeBoxedBoolean();
+
+    if(badBoolean) { // Noncompliant
+      foo();
+    } else {
+      bar();
+    }
+
+    @NonNull Boolean goodBoolean = getSurprizeBoxedBoolean();
+
+    if(goodBoolean) {
+      foo();
+    } else {
+      bar();
+    }
+  }
 }

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

@@ -217,7 +217,7 @@ private static Optional<IfStatementTree> getParentConditionalBranch(Tree tree) {
 
   @CheckForNull
   private static ExpressionTree findBoxedBoolean(ExpressionTree tree) {
-    if (tree.symbolType().is(BOOLEAN) && !isValidMethodInvocation(tree)) {
+    if (tree.symbolType().is(BOOLEAN) && !isValidMethodInvocation(tree) && !isNonnullIdentifier(tree)) {
       return tree;
     }
     if (tree.is(Kind.LOGICAL_COMPLEMENT)) {
@@ -245,7 +245,7 @@ private static boolean isNullCheck(ExpressionTree tree) {
   private static boolean isValidMethodInvocation(ExpressionTree tree) {
     if (tree.is(Kind.METHOD_INVOCATION)) {
       MethodInvocationTree mit = (MethodInvocationTree) tree;
-      return isOptionalInvocation(mit) || isAnnotatedNonnull(mit);
+      return isOptionalInvocation(mit) || isAnnotatedNonnull(mit.methodSymbol());
     }
     return false;
   }
@@ -254,8 +254,12 @@ private static boolean isOptionalInvocation(MethodInvocationTree mit) {
     return OPTIONAL_OR_ELSE.matches(mit) && !mit.arguments().get(0).is(Kind.NULL_LITERAL);
   }
 
-  private static boolean isAnnotatedNonnull(MethodInvocationTree mit) {
-    return mit.methodSymbol().metadata()
+  private static boolean isNonnullIdentifier(ExpressionTree tree) {
+    return tree instanceof IdentifierTree it && isAnnotatedNonnull(it.symbol());
+  }
+
+  private static boolean isAnnotatedNonnull(Symbol symbol) {
+    return symbol.metadata()
       .annotations()
       .stream()
       .map(SymbolMetadata.AnnotationInstance::symbol)