Merge pull request #7008 from JLLeitschuh/feat/JLL/java_optional_lambda_support

Java: Model java.util.Optional lambda methods

java/ql/test/library-tests/optional/FunctionalTest.java

@@ -0,0 +1,58 @@
+import java.util.Optional;
+
+public class FunctionalTest {
+    String source() {
+        return null;
+    }
+
+    void sink(Object o) {
+    }
+
+    void test() {
+        Optional<String> o = Optional.of(source());
+        o.ifPresent(v -> {
+            sink(v); // $hasValueFlow
+        });
+        o.ifPresentOrElse(v -> {
+            sink(v); // $hasValueFlow
+        }, () -> {
+            // no-op
+        });
+        o.map(v -> {
+            sink(v); // $hasValueFlow
+            return v;
+        }).ifPresent(v -> {
+            sink(v); // $hasValueFlow
+        });
+        o.flatMap(v -> {
+            sink(v); // $hasValueFlow
+            return Optional.of(v);
+        }).ifPresent(v -> {
+            sink(v); // $hasValueFlow
+        });
+        o.flatMap(v -> {
+            sink(v); // $hasValueFlow
+            return Optional.of("safe");
+        }).ifPresent(v -> {
+            sink(v); // no value flow
+        });
+        o.filter(v -> {
+            sink(v); // $hasValueFlow
+            return true;
+        }).ifPresent(v -> {
+            sink(v); // $hasValueFlow
+        });
+        Optional.of("safe").map(v -> {
+            sink(v); // no value flow
+            return v;
+        }).or(() -> o).ifPresent(v -> {
+            sink(v); // $hasValueFlow
+        });
+        Optional<String> safe = Optional.of("safe");
+        o.or(() -> safe).ifPresent(v -> {
+            sink(v); // $hasValueFlow
+        });
+        String value = safe.orElseGet(() -> source());
+        sink(value); // $hasValueFlow
+    }
+}