Only add hamcrest-junit dependency when using assertThat or assumeThat

src/main/java/org/openrewrite/java/testing/hamcrest/AddHamcrestJUnitDependency.java

@@ -0,0 +1,89 @@
+/*
+ * 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.hamcrest;
+
+import org.openrewrite.ExecutionContext;
+import org.openrewrite.ScanningRecipe;
+import org.openrewrite.Tree;
+import org.openrewrite.TreeVisitor;
+import org.openrewrite.java.MethodMatcher;
+import org.openrewrite.java.dependencies.AddDependency;
+import org.openrewrite.java.tree.JavaSourceFile;
+import org.openrewrite.java.tree.JavaType;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public class AddHamcrestJUnitDependency extends ScanningRecipe<AtomicBoolean> {
+
+    @Override
+    public String getDisplayName() {
+        return "Add Hamcrest JUnit dependency";
+    }
+
+    @Override
+    public String getDescription() {
+        return "Add Hamcrest JUnit dependency only if JUnit 4's `assertThat` or `assumeThat` is used.";
+    }
+
+    @Override
+    public AtomicBoolean getInitialValue(ExecutionContext ctx) {
+        return new AtomicBoolean(false);
+    }
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getScanner(AtomicBoolean acc) {
+        // No need to scan for AddDependency, as we'll unconditionally add the dependency if we find a match below
+        MethodMatcher methodMatcher = new MethodMatcher("org.junit.Ass* *That(..)");
+        return new TreeVisitor<Tree, ExecutionContext>() {
+            @Override
+            public Tree preVisit(Tree tree, ExecutionContext ctx) {
+                stopAfterPreVisit();
+                if (tree instanceof JavaSourceFile && !acc.get()) {
+                    for (JavaType.Method type : ((JavaSourceFile) tree).getTypesInUse().getUsedMethods()) {
+                        if (methodMatcher.matches(type)) {
+                            acc.set(true);
+                        }
+                    }
+                }
+                return tree;
+            }
+        };
+    }
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getVisitor(AtomicBoolean acc) {
+        if (acc.get()) {
+            // We can unconditionally add the dependency here
+            return new AddDependency(
+                    "org.hamcrest",
+                    "hamcrest-junit",
+                    "2.x",
+                    null,
+                    null,
+                    null,
+                    null,
+                    null,
+                    null,
+                    "test",
+                    null,
+                    null,
+                    null,
+                    true
+            ).getVisitor();
+        }
+        return TreeVisitor.noop();
+    }
+}

src/main/resources/META-INF/rewrite/junit5.yml

@@ -160,13 +160,7 @@ tags:
   - junit
   - hamcrest
 recipeList:
-  - org.openrewrite.java.dependencies.AddDependency:
-      groupId: org.hamcrest
-      artifactId: hamcrest-junit
-      version: 2.x
-      scope: test
-      onlyIfUsing: org.junit.Assume
-      acceptTransitive: true
+  - org.openrewrite.java.testing.junit5.AddHamcrestJUnitDependency
   - org.openrewrite.java.ChangeMethodTargetToStatic:
       methodPattern: org.junit.Assume assumeThat(..)
       fullyQualifiedTargetTypeName: org.hamcrest.junit.MatcherAssume

src/test/java/org/openrewrite/java/testing/hamcrest/AddHamcrestJUnitDependencyTest.java

@@ -0,0 +1,132 @@
+/*
+ * 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.hamcrest;
+
+import org.intellij.lang.annotations.Language;
+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;
+import static org.openrewrite.maven.Assertions.pomXml;
+
+class AddHamcrestJUnitDependencyTest implements RewriteTest {
+
+    @Language("xml")
+    private static final String POM_BEFORE = """
+      <project>
+          <groupId>org.example</groupId>
+          <artifactId>project</artifactId>
+          <version>1.0-SNAPSHOT</version>
+          <dependencies>
+              <dependency>
+                  <groupId>junit</groupId>
+                  <artifactId>junit</artifactId>
+                  <version>4.13.2</version>
+                  <scope>test</scope>
+              </dependency>
+          </dependencies>
+      </project>
+      """;
+
+    @Language("xml")
+    private static final String POM_AFTER = """
+      <project>
+          <groupId>org.example</groupId>
+          <artifactId>project</artifactId>
+          <version>1.0-SNAPSHOT</version>
+          <dependencies>
+              <dependency>
+                  <groupId>junit</groupId>
+                  <artifactId>junit</artifactId>
+                  <version>4.13.2</version>
+                  <scope>test</scope>
+              </dependency>
+              <dependency>
+                  <groupId>org.hamcrest</groupId>
+                  <artifactId>hamcrest-junit</artifactId>
+                  <version>2.0.0.0</version>
+                  <scope>test</scope>
+              </dependency>
+          </dependencies>
+      </project>
+      """;
+
+    @Override
+    public void defaults(RecipeSpec spec) {
+        spec.recipe(new AddHamcrestJUnitDependency())
+          .parser(JavaParser.fromJavaVersion().classpathFromResources(new InMemoryExecutionContext(),
+            "hamcrest",
+            "junit-4"));
+
+    }
+
+    @Test
+    @DocumentExample
+    void shouldAddWhenUsingAssertThat() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              class FooTest {
+                  void bar() {
+                      org.junit.Assert.assertThat("a", org.hamcrest.Matchers.is("a"));
+                  }
+              }
+              """
+          ),
+          pomXml(POM_BEFORE, POM_AFTER)
+        );
+    }
+
+    @Test
+    void shouldAddWhenUsingAssumeThat() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              class FooTest {
+                  void bar() {
+                      org.junit.Assume.assumeThat("a", org.hamcrest.Matchers.is("a"));
+                  }
+              }
+              """
+          ),
+          pomXml(POM_BEFORE, POM_AFTER)
+        );
+    }
+
+    @Test
+    void shouldNotAddWhenUsingAssertTrue() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              class FooTest {
+                  void bar() {
+                      org.junit.Assume.assumeTrue(true);
+                      org.junit.Assert.assertTrue(true);
+                  }
+              }
+              """
+          ),
+          pomXml(POM_BEFORE)
+        );
+    }
+}