/*
 * Copyright 2020 The Error Prone Authors.
 *
 * 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.google.errorprone.bugpatterns;

import com.google.errorprone.BugCheckerRefactoringTestHelper;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Tests for {@link OptionalMapUnusedValue} bugpattern. */
@RunWith(JUnit4.class)
public final class OptionalMapUnusedValueTest {
  private final BugCheckerRefactoringTestHelper helper =
      BugCheckerRefactoringTestHelper.newInstance(OptionalMapUnusedValue.class, getClass());

  @Test
  public void positive_methodReference() {
    helper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              private Integer foo(Integer v) {
                return v;
              }

              public void bar(Optional<Integer> optional) {
                optional.map(this::foo);
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              private Integer foo(Integer v) {
                return v;
              }

              public void bar(Optional<Integer> optional) {
                optional.ifPresent(this::foo);
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positive_statementLambda() {
    helper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              private Integer foo(Integer v) {
                return v;
              }

              public void bar(Optional<Integer> optional) {
                optional.map(v -> foo(v));
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              private Integer foo(Integer v) {
                return v;
              }

              public void bar(Optional<Integer> optional) {
                optional.ifPresent(v -> foo(v));
              }
            }
            """)
        .doTest();
  }

  @Test
  public void negative_resultReturned() {
    helper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              private Integer foo(Integer v) {
                return v;
              }

              public Optional<Integer> bar(Optional<Integer> optional) {
                return optional.map(this::foo);
              }
            }
            """)
        .expectUnchanged()
        .doTest();
  }

  @Test
  public void negative_resultAssigned() {
    helper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              private Integer foo(Integer v) {
                return v;
              }

              public void bar(Optional<Integer> optional) {
                Optional<Integer> result = optional.map(this::foo);
              }
            }
            """)
        .expectUnchanged()
        .doTest();
  }

  @Test
  public void negative_resultMethodCall() {
    helper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              private Integer foo(Integer v) {
                return v;
              }

              public void bar(Optional<Integer> optional) {
                optional.map(this::foo).orElse(42);
              }
            }
            """)
        .expectUnchanged()
        .doTest();
  }

  @Test
  public void negative_nonStatementLambda() {
    helper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              public void bar(Optional<Integer> optional) {
                optional.map(v -> v + 1);
              }
            }
            """)
        .expectUnchanged()
        .doTest();
  }

  @Test
  public void negative_voidIncompatibleLambdaBlock() {
    helper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              public void bar(Optional<Integer> optional) {
                optional.map(
                    v -> {
                      return 2;
                    });
              }
            }
            """)
        .expectUnchanged()
        .doTest();
  }
}
