LogicOperations.java

import org.checkerframework.checker.nullness.qual.*;
import org.checkerframework.checker.nullness.qual.NonNull;

class LogicOperations {
    void andTrueClause(@Nullable Object a) {
        if (a != null && helper()) {
            a.toString();
        }
    }

    void andTrueClauseReverse(@Nullable Object a) {
        if (helper() && a != null) {
            a.toString();
        }
    }

    void oneAndComplement(@Nullable Object a) {
        if (a != null && helper()) {
            a.toString();
            return;
        }
        //:: error: (dereference.of.nullable)
        a.toString(); // error
    }

    void repAndComplement(@Nullable Object a, @Nullable Object b) {
        if (a == null && b == null) {
            //:: error: (dereference.of.nullable)
            a.toString(); // error
            return;
        }
        //:: error: (dereference.of.nullable)
        a.toString(); // error
    }

    void oneOrComplement(@Nullable Object a) {
        if (a == null || helper()) {
            //:: error: (dereference.of.nullable)
            a.toString(); // error
            return;
        }
        a.toString();
    }

    void simpleOr1(@Nullable Object a, @Nullable Object b) {
        if (a != null || b != null) {
            //:: error: (dereference.of.nullable)
            a.toString(); // error
        }
    }

    void simpleOr2(@Nullable Object a, @Nullable Object b) {
        if (a != null || b != null) {
            //:: error: (dereference.of.nullable)
            b.toString(); // error
        }
    }

    void sideeffect() {
        Object a = "m";
        if ((a = null) != "n") {
            //:: error: (assignment.type.incompatible)
            @NonNull Object l1 = a;
        }
        //:: error: (assignment.type.incompatible)
        @NonNull Object l2 = a;
    }

    static boolean helper() {
        return true;
    }
}