/*
 * Copyright 2022 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 com.google.errorprone.CompilationTestHelper;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

@RunWith(JUnit4.class)
public final class MockNotUsedInProductionTest {
  private final CompilationTestHelper helper =
      CompilationTestHelper.newInstance(MockNotUsedInProduction.class, getClass());

  private final BugCheckerRefactoringTestHelper refactoring =
      BugCheckerRefactoringTestHelper.newInstance(MockNotUsedInProduction.class, getClass());

  @Test
  public void neverUsed() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;

            class Test {
              public Object test() {
                // BUG: Diagnostic contains:
                Test test = mock(Test.class);
                when(test.test()).thenCallRealMethod();
                return null;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void neverUsed_butInitializedSeparately() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;

            class Test {
              private Test test;

              public Object test() {
                // BUG: Diagnostic contains:
                test = mock(Test.class);
                when(test.test()).thenCallRealMethod();
                return null;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void spyNeverUsed() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import static org.mockito.Mockito.spy;
            import static org.mockito.Mockito.verify;

            class Test {
              public Object test() {
                // BUG: Diagnostic contains:
                Test test = spy(new Test());
                verify(test).test();
                return null;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void nonStaticVerify_countsAsUse() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import static org.mockito.Mockito.spy;

            class Test {
              public Object test() {
                Test test = spy(new Test());
                verify(test).test();
                return null;
              }

              Test verify(Test t) {
                return t;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void passedToProduction() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;

            class Test {
              public Object test() {
                Test test = mock(Test.class);
                when(test.test()).thenCallRealMethod();
                return test.test();
              }
            }
            """)
        .doTest();
  }

  @Test
  public void possiblyBound() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;
            import com.google.inject.testing.fieldbinder.Bind;
            import org.mockito.Mock;

            class Test {
              @Bind @Mock public Test test;

              public Object test() {
                when(test.test()).thenCallRealMethod();
                return null;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void publicField() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;
            import org.mockito.Mock;

            class Test {
              @Mock public Test test;

              public Object test() {
                when(test.test()).thenCallRealMethod();
                return null;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void qualifiedWithThis_stillSeen() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;
            import org.mockito.Mock;

            class Test {
              @Mock private Test test;

              public Test test() {
                return this.test;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void privateField() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;
            import org.mockito.Mock;

            class Test {
              // BUG: Diagnostic contains:
              @Mock private Test test;

              public Object test() {
                when(test.test()).thenCallRealMethod();
                return null;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void injectMocks_noFinding() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;
            import org.mockito.InjectMocks;
            import org.mockito.Mock;

            class Test {
              @Mock private Test test;
              @InjectMocks Test t;

              public Object test() {
                when(test.test()).thenCallRealMethod();
                return null;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void suppressionWorks() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;
            import org.mockito.Mock;

            class Test {
              @SuppressWarnings("MockNotUsedInProduction")
              @Mock
              private Test test;

              public Object test() {
                when(test.test()).thenCallRealMethod();
                return null;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void refactoring() {
    refactoring
        .addInputLines(
            "Test.java",
            """
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;
            import org.mockito.Mock;

            class Test {
              @Mock private Test test;

              public Object test() {
                when(test.test()).thenCallRealMethod();
                return null;
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;
            import org.mockito.Mock;

            class Test {
              public Object test() {
                return null;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void refactoringNested() {
    refactoring
        .addInputLines(
            "Test.java",
            """
            import static org.mockito.Mockito.doAnswer;
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;
            import org.mockito.Mock;

            class Test {
              @Mock private Test test;

              public Object test() {
                doAnswer(
                        a -> {
                          when(test.test()).thenReturn(null);
                          return null;
                        })
                    .when(test)
                    .test();
                return null;
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import static org.mockito.Mockito.doAnswer;
            import static org.mockito.Mockito.mock;
            import static org.mockito.Mockito.when;
            import org.mockito.Mock;

            class Test {
              public Object test() {
                return null;
              }
            }
            """)
        .doTest();
  }
}
