Add refaster recipes to simplify expected value

build.gradle.kts

@@ -52,4 +52,20 @@ dependencies {
 
 //    testImplementation("org.hamcrest:hamcrest:latest.release")
 //    testImplementation("org.assertj:assertj-core:latest.release")
+
+    // The bom version can also be set to a specific version
+    // https://github.com/openrewrite/rewrite-recipe-bom/releases
+    implementation(platform("org.openrewrite.recipe:rewrite-recipe-bom:latest.release"))
+
+    // Refaster style recipes need the rewrite-templating annotation processor and dependency for generated recipes
+    // https://github.com/openrewrite/rewrite-templating/releases
+    annotationProcessor("org.openrewrite:rewrite-templating:latest.release")
+    implementation("org.openrewrite:rewrite-templating")
+    // The `@BeforeTemplate` and `@AfterTemplate` annotations are needed for refaster style recipes
+    compileOnly("com.google.errorprone:error_prone_core:2.19.1") {
+        exclude("com.google.auto.service", "auto-service-annotations")
+    }
+
+    implementation("org.assertj:assertj-core:3.+")
+
 }

src/main/java/org/openrewrite/java/testing/assertj/SimplifyAssertExpectations.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2024 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.assertj;
+
+import com.google.errorprone.refaster.annotation.AfterTemplate;
+import com.google.errorprone.refaster.annotation.BeforeTemplate;
+import org.openrewrite.java.template.RecipeDescriptor;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@RecipeDescriptor(
+        name = "Simplify the expectations of assertions",
+        description = "Simplifies expectations on various assertions."
+)
+public class SimplifyAssertExpectations {
+
+    @RecipeDescriptor(
+            name = "Simplify `assertThat(int).isEqualTo(0)`",
+            description = "Simplify `assertThat(int).isEqualTo(0)` to `assertThat(int).isZero()`."
+    )
+    public class SimplifyToIsZero {
+
+        @BeforeTemplate
+        void before(Integer i) {
+            assertThat(i).isEqualTo(0);
+        }
+
+        @AfterTemplate
+        void after(Integer i) {
+            assertThat(i).isZero();
+        }
+    }
+
+    @RecipeDescriptor(
+            name = "Simplify `assertThat(o).isEqualTo(null)`",
+            description = "Simplify `assertThat(o).isEqualTo(null)` to `assertThat(o).isNull()`."
+    )
+    public class SimplifyToIsNull {
+
+        @BeforeTemplate
+        void before(Object o) {
+            assertThat(o).isEqualTo(null);
+        }
+
+        @AfterTemplate
+        void after(Object o) {
+            assertThat(o).isNull();
+        }
+    }
+
+    @RecipeDescriptor(
+            name = "Simplify `assertThat(i >= j).isTrue()`",
+            description = "Simplify `assertThat(i >= j).isTrue()` to `assertThat(i).isGreaterThanOrEqualTo(j)`."
+    )
+    public class SimplifyGreaterEqualComparison {
+
+        @BeforeTemplate
+        void before(Integer i, Integer j) {
+            assertThat(i >= j).isTrue();
+        }
+
+        @AfterTemplate
+        void after(Integer i, Integer j) {
+            assertThat(i).isGreaterThanOrEqualTo(j);
+        }
+    }
+}

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

@@ -26,6 +26,7 @@ recipeList:
   - org.openrewrite.java.testing.assertj.JUnitToAssertj
   - org.openrewrite.java.testing.assertj.StaticImports
   - org.openrewrite.java.testing.assertj.SimplifyChainedAssertJAssertions
+  - org.openrewrite.java.testing.assertj.SimplifyAssertExpectationsRecipes
 
 ---
 type: specs.openrewrite.org/v1beta/recipe

src/test/java/org/openrewrite/java/testing/assertj/SimplifyAssertExpectationsTest.java

@@ -0,0 +1,146 @@
+/*
+ * Copyright 2024 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.assertj;
+
+import org.junit.jupiter.api.Test;
+import org.openrewrite.DocumentExample;
+import org.openrewrite.java.JavaParser;
+import org.openrewrite.test.RecipeSpec;
+import org.openrewrite.test.RewriteTest;
+
+import static org.openrewrite.java.Assertions.java;
+
+class SimplifyAssertExpectationsTest implements RewriteTest {
+
+    @Override
+    public void defaults(RecipeSpec spec) {
+        spec.parser(JavaParser.fromJavaVersion().classpath("assertj-core"))
+                .recipe(new SimplifyAssertExpectationsRecipes());
+    }
+
+    @DocumentExample
+    @Test
+    void simplifyIsZero() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              import static org.assertj.core.api.Assertions.assertThat;
+              import java.util.List;
+              import org.junit.jupiter.api.Test;
+
+              class Test {
+
+                  @Test
+                  void simpleTest() {
+                      List<String> list = List.of();
+                      assertThat(list.size()).isEqualTo(0);
+                      assertThat(0).isEqualTo(0);
+                      assertThat(list.size()).isNotEqualTo(0);
+                  }
+              }
+              """,
+            """
+              import static org.assertj.core.api.Assertions.assertThat;
+              import java.util.List;
+              import org.junit.jupiter.api.Test;
+
+              class Test {
+
+                  @Test
+                  void simpleTest() {
+                      List<String> list = List.of();
+                      assertThat(list.size()).isZero();
+                      assertThat(0).isZero();
+                      assertThat(list.size()).isNotZero();
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void simplifyIsNull() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              import static org.assertj.core.api.Assertions.assertThat;
+              import org.junit.jupiter.api.Test;
+
+              class Test {
+
+                  @Test
+                  void simpleTest() {
+                      String s = null;
+                      assertThat(s).isEqualTo(null);
+                      assertThat(s).isNotEqualTo(null);
+                  }
+              }
+              """,
+            """
+              import static org.assertj.core.api.Assertions.assertThat;
+              import org.junit.jupiter.api.Test;
+
+              class Test {
+
+                  @Test
+                  void simpleTest() {
+                      String s = null;
+                      assertThat(s).isNull();
+                      assertThat(s).isNull();
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void simplifyIsGreaterThanOrEqual() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              import static org.assertj.core.api.Assertions.assertThat;
+              import org.junit.jupiter.api.Test;
+
+              class Test {
+
+                  @Test
+                  void simpleTest() {
+                      assertThat(2 >= 1).isTrue();
+                  }
+              }
+              """,
+            """
+              import static org.assertj.core.api.Assertions.assertThat;
+              import org.junit.jupiter.api.Test;
+
+              class Test {
+
+                  @Test
+                  void simpleTest() {
+                      assertThat(2).isGreaterThanOrEqualTo(1);
+                  }
+              }
+              """
+          )
+        );
+    }
+
+}