- Introduce NoInitializationForInjectMock and use it in mockito.yml

- Let easymock apply MockitoBestPractices

src/main/java/org/openrewrite/java/testing/mockito/NoInitializationForInjectMock.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2021 the original author or authors.
+ * <p>
+ * 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
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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 org.openrewrite.java.testing.mockito;
+
+import org.openrewrite.ExecutionContext;
+import org.openrewrite.Preconditions;
+import org.openrewrite.Recipe;
+import org.openrewrite.TreeVisitor;
+import org.openrewrite.java.AnnotationMatcher;
+import org.openrewrite.java.JavaIsoVisitor;
+import org.openrewrite.java.search.UsesType;
+import org.openrewrite.java.service.AnnotationService;
+import org.openrewrite.java.tree.J;
+
+import java.util.stream.Collectors;
+
+public class NoInitializationForInjectMock extends Recipe {
+
+    private static final AnnotationMatcher INJECT_MOCKS = new AnnotationMatcher("@org.mockito.InjectMocks");
+
+    @Override
+    public String getDisplayName() {
+        return "Remove initialization when using @InjectMocks";
+    }
+
+    @Override
+    public String getDescription() {
+        return "Removes unnecessary initialization for fields annotated with @InjectMocks in Mockito tests.";
+    }
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getVisitor() {
+        return Preconditions.check(new UsesType<>("org.mockito.*", false), new JavaIsoVisitor<ExecutionContext>() {
+            @Override
+            public J.VariableDeclarations visitVariableDeclarations(J.VariableDeclarations variableDeclarations, ExecutionContext ctx) {
+                J.VariableDeclarations vd = super.visitVariableDeclarations(variableDeclarations, ctx);
+
+                if (new AnnotationService().matches(getCursor(), INJECT_MOCKS)) {
+                    return vd.withVariables(vd.getVariables().stream().map(var -> var.withInitializer(null)).collect(Collectors.toList()));
+                }
+
+                return vd;
+            }
+        });
+    }
+}

src/main/resources/META-INF/rewrite/easymock.yml

@@ -128,6 +128,7 @@ recipeList:
       oldFullyQualifiedTypeName: org.easymock.TestSubject
       newFullyQualifiedTypeName: org.mockito.InjectMocks
   #  - com.todo.openrewrite.java.easymock.RefactorEasyMockIArgumentMatcherIntoMockitoArgumentMatcher
+  - org.openrewrite.java.testing.mockito.MockitoBestPractices
   - org.openrewrite.java.dependencies.AddDependency:
       groupId: org.mockito
       artifactId: mockito-core

src/main/resources/META-INF/rewrite/mockito.yml

@@ -151,6 +151,7 @@ recipeList:
   - org.openrewrite.java.ChangeType:
       oldFullyQualifiedTypeName: org.mockito.runners.MockitoJUnitRunner
       newFullyQualifiedTypeName: org.mockito.junit.MockitoJUnitRunner
+  - org.openrewrite.java.testing.mockito.NoInitializationForInjectMock
   - org.openrewrite.java.testing.mockito.CleanupMockitoImports
   - org.openrewrite.java.testing.mockito.MockUtilsToStatic
   - org.openrewrite.java.testing.junit5.MockitoJUnitToMockitoExtension

src/test/java/org/openrewrite/java/testing/mockito/NoInitializationForInjectMockTest.java

@@ -0,0 +1,63 @@
+package org.openrewrite.java.testing.mockito;
+
+import org.junit.jupiter.api.Test;
+import org.openrewrite.DocumentExample;
+import org.openrewrite.InMemoryExecutionContext;
+import org.openrewrite.java.JavaParser;
+import org.openrewrite.test.RecipeSpec;
+import org.openrewrite.test.RewriteTest;
+
+import static org.openrewrite.java.Assertions.java;
+
+class NoInitializationForInjectMockTest implements RewriteTest {
+    @Override
+    public void defaults(RecipeSpec spec) {
+        spec
+          .parser(JavaParser.fromJavaVersion()
+            .classpathFromResources(new InMemoryExecutionContext(), "junit-jupiter-api-5.9", "mockito-junit-jupiter-3.12", "mockito-core-3.12"))
+          .recipe(new NoInitializationForInjectMock());
+    }
+
+    @Test
+    @DocumentExample
+    void removeInitializationOfInjectMocks() {
+        //language=java
+        rewriteRun(
+          java(
+            """
+              class MyObject {
+                  private String someField;
+
+                  public MyObject(String someField) {
+                      this.someField = someField;
+                  }
+              }
+              """
+          ),
+          java(
+            """
+              import org.junit.jupiter.api.extension.ExtendWith;
+              import org.mockito.InjectMocks;
+              import org.mockito.junit.jupiter.MockitoExtension;
+
+              @ExtendWith(MockitoExtension.class)
+              class MyTest {
+                  @InjectMocks
+                  MyObject myObject = new MyObject("someField");
+              }
+              """,
+              """
+              import org.junit.jupiter.api.extension.ExtendWith;
+              import org.mockito.InjectMocks;
+              import org.mockito.junit.jupiter.MockitoExtension;
+
+              @ExtendWith(MockitoExtension.class)
+              class MyTest {
+                  @InjectMocks
+                  MyObject myObject;
+              }
+              """
+          )
+        );
+    }
+}