AssertAfter2.java

import java.util.HashMap;
import java.util.List;
import org.checkerframework.checker.nullness.qual.*;
import org.checkerframework.checker.nullness.qual.EnsuresNonNull;

public class AssertAfter2 {

    public class Graph<T> {

        HashMap<T, List<@KeyFor("childMap") T>> childMap;

        public Graph(HashMap<T, List<@KeyFor("childMap") T>> childMap) {
            this.childMap = childMap;
        }

        @SuppressWarnings("contracts.postcondition.not.satisfied")
        @EnsuresNonNull("childMap.get(#1)")
        public void addNode(final T n) {
            // body omitted, not relevant to test case
        }

        public void addEdge(T parent, T child) {
            addNode(parent);
            @NonNull List<@KeyFor("childMap") T> l = childMap.get(parent);
        }

        public void addEdgeBad1(T parent, T child) {
            //:: error: (assignment.type.incompatible)
            @NonNull List<@KeyFor("childMap") T> l = childMap.get(parent);
        }

        public void addEdgeBad2(T parent, T child) {
            addNode(parent);
            //:: error: (assignment.type.incompatible)
            @NonNull List<@KeyFor("childMap") T> l = childMap.get(child);
        }

        public void addEdgeBad3(T parent, T child) {
            addNode(parent);
            parent = child;
            //:: error: (assignment.type.incompatible)
            @NonNull List<@KeyFor("childMap") T> l = childMap.get(parent);
        }

        public void addEdgeOK(T parent, T child) {
            List<@KeyFor("childMap") T> l = childMap.get(parent);
        }
    }

    class MultiParam {

        MultiParam(MultiParam thing, Object f1, Object f2, Object f3) {
            this.thing = thing;
            this.f1 = f1;
            this.f2 = f2;
            this.f3 = f3;
        }

        MultiParam thing;

        @SuppressWarnings("contracts.postcondition.not.satisfied")
        @EnsuresNonNull("get(#1, #2, #3)")
        void add(final Object o1, final Object o2, final Object o3) {
            // body omitted, not relevant to test case
        }

        @org.checkerframework.dataflow.qual.Pure
        @Nullable Object get(Object o1, Object o2, Object o3) {
            return null;
        }

        Object f1, f2, f3;

        void addGood1() {
            thing.add(f1, f2, f3);
            @NonNull Object nn = thing.get(f1, f2, f3);
        }

        void addBad1() {
            //:: error: (assignment.type.incompatible)
            @NonNull Object nn = get(f1, f2, f3);
        }

        void addBad2() {
            thing.add(f1, f2, f3);
            f1 = new Object();
            //:: error: (assignment.type.incompatible)
            @NonNull Object nn = thing.get(f1, f2, f3);
        }

        void addBad3() {
            thing.add(f1, f2, f3);
            f2 = new Object();
            //:: error: (assignment.type.incompatible)
            @NonNull Object nn = thing.get(f1, f2, f3);
        }

        void addBad4() {
            thing.add(f1, f2, f3);
            f3 = new Object();
            //:: error: (assignment.type.incompatible)
            @NonNull Object nn = thing.get(f1, f2, f3);
        }
    }
}