/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.facebook.presto.sql.planner.plan;

import com.facebook.presto.sql.planner.Symbol;
import com.facebook.presto.sql.tree.Expression;
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;

import javax.annotation.concurrent.Immutable;

import java.util.List;
import java.util.Map;

@Immutable
public class ProjectNode
        extends PlanNode
{
    private final PlanNode source;
    private final Map<Symbol, Expression> assignments;
    private final List<Symbol> outputs;

    // TODO: pass in the "assignments" and the "outputs" separately (i.e., get rid if the symbol := symbol idiom)
    @JsonCreator
    public ProjectNode(@JsonProperty("id") PlanNodeId id,
            @JsonProperty("source") PlanNode source,
            @JsonProperty("assignments") Map<Symbol, Expression> assignments)
    {
        super(id);

        this.source = source;
        this.assignments = ImmutableMap.copyOf(assignments);
        this.outputs = ImmutableList.copyOf(assignments.keySet());
    }

    @Override
    public List<Symbol> getOutputSymbols()
    {
        return outputs;
    }

    @JsonProperty
    public Map<Symbol, Expression> getAssignments()
    {
        return assignments;
    }

    @Override
    public List<PlanNode> getSources()
    {
        return ImmutableList.of(source);
    }

    @JsonProperty
    public PlanNode getSource()
    {
        return source;
    }

    @Override
    public <C, R> R accept(PlanVisitor<C, R> visitor, C context)
    {
        return visitor.visitProject(this, context);
    }
}

@@ -993,16 +993,65 @@
 l.Map;%0A%0A
+import static java.util.Objects.requireNonNull;%0A%0A
 @Immutab
@@ -1582,16 +1582,127 @@
 r(id);%0A%0A
+        requireNonNull(source, %22source is null%22);%0A        requireNonNull(assignments, %22assignments is null%22);%0A%0A
         

Add preconditions to ProjectNode constructor