cat > a.java <<'EOL'
public sealed interface A {
    record AA(Long a) implements A {}
    record AAA(String b) implements A {}
    static Long mySwitch(A a) {
        switch (a) {
            case AA(var aa) -> {
                return aa;
            }
            case AAA(var b) -> {
                return Long.parseLong(b);
            }
        }
    }
}
EOL

java -jar google-java-format-1.19.1-all-deps.jar -r a.java
a.java:6:22: error: expected token: 'var'; generated aa instead