software.amazon.smithy.linters.InputOutputStructureReuseValidator Maven / Gradle / Ivy

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/*
 * Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file 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 software.amazon.smithy.linters;

import java.util.ArrayList;
import java.util.List;
import software.amazon.smithy.model.Model;
import software.amazon.smithy.model.knowledge.OperationIndex;
import software.amazon.smithy.model.shapes.OperationShape;
import software.amazon.smithy.model.shapes.StructureShape;
import software.amazon.smithy.model.traits.InputTrait;
import software.amazon.smithy.model.traits.OutputTrait;
import software.amazon.smithy.model.validation.AbstractValidator;
import software.amazon.smithy.model.validation.ValidationEvent;
import software.amazon.smithy.model.validation.ValidatorService;

/**
 * Validates that all operations define input and output structures that are marked
 * with the input and output traits.
 */
public final class InputOutputStructureReuseValidator extends AbstractValidator {

    public static final class Provider extends ValidatorService.Provider {
        public Provider() {
            super(InputOutputStructureReuseValidator.class, InputOutputStructureReuseValidator::new);
        }
    }

    private static final String INPUT = "Input";
    private static final String OUTPUT = "Output";

    @Override
    public List validate(Model model) {
        List events = new ArrayList<>();
        OperationIndex index = OperationIndex.of(model);
        for (OperationShape operation : model.getOperationShapes()) {
            StructureShape input = index.expectInputShape(operation);
            StructureShape output = index.expectOutputShape(operation);
            validateInputOutputSet(operation, input, output, events);
        }
        return events;
    }

    private void validateInputOutputSet(
            OperationShape operation,
            StructureShape input,
            StructureShape output,
            List events
    ) {
        if (!input.hasTrait(InputTrait.class)) {
            events.add(warning(input, String.format(
                    "This structure is the input of `%s`, but it is not marked with the "
                    + "@input trait. The @input trait gives operations more flexibility to "
                    + "evolve their top-level input members in ways that would otherwise "
                    + "be backward incompatible.", operation.getId()),
                    INPUT, operation.getId().getName()));
        }

        if (!output.hasTrait(OutputTrait.class)) {
            events.add(warning(output, String.format(
                    "This structure is the output of `%s`, but it is not marked with "
                    + "the @output trait.", operation.getId()),
                    OUTPUT, operation.getId().getName()));
        }
    }
}