Convert Guava Functions.compose

src/main/java/org/openrewrite/java/migrate/guava/NoGuavaFunctionsCompose.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2025 the original author or authors.
+ * <p>
+ * Licensed under the Moderne Source Available License (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://docs.moderne.io/licensing/moderne-source-available-license
+ * <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.migrate.guava;
+
+import org.openrewrite.ExecutionContext;
+import org.openrewrite.Preconditions;
+import org.openrewrite.Recipe;
+import org.openrewrite.TreeVisitor;
+import org.openrewrite.java.JavaIsoVisitor;
+import org.openrewrite.java.JavaTemplate;
+import org.openrewrite.java.MethodMatcher;
+import org.openrewrite.java.search.UsesMethod;
+import org.openrewrite.java.tree.J;
+
+import java.util.Set;
+
+import static java.util.Collections.singleton;
+
+public class NoGuavaFunctionsCompose extends Recipe {
+    private static final MethodMatcher FUNCTIONS_COMPOSE = new MethodMatcher("com.google.common.base.Functions compose(com.google.common.base.Function, com.google.common.base.Function)");
+
+    @Override
+    public String getDisplayName() {
+        return "Prefer `Function.compose(Function)`";
+    }
+
+    @Override
+    public String getDescription() {
+        return "Prefer `Function.compose(Function)` over `Functions.compose(Function, Function)`.";
+    }
+
+    @Override
+    public Set<String> getTags() {
+        return singleton("guava");
+    }
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getVisitor() {
+        return Preconditions.check(
+                new UsesMethod<>(FUNCTIONS_COMPOSE),
+                new JavaIsoVisitor<ExecutionContext>() {
+                    @Override
+                    public J.MethodInvocation visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx) {
+                        if (FUNCTIONS_COMPOSE.matches(method)) {
+                            maybeRemoveImport("com.google.common.base.Function");
+                            maybeRemoveImport("com.google.common.base.Functions");
+                            maybeAddImport("java.util.function.Function");
+
+                            return JavaTemplate.builder("#{any(java.util.function.Function)}.compose(#{any(java.util.function.Function)})")
+                                    .build()
+                                    .apply(getCursor(),
+                                            method.getCoordinates().replace(),
+                                            method.getArguments().get(0),
+                                            method.getArguments().get(1));
+                        }
+                        return super.visitMethodInvocation(method, ctx);
+                    }
+                }
+        );
+    }
+}

src/main/resources/META-INF/rewrite/no-guava.yml

@@ -29,6 +29,7 @@ recipeList:
   - org.openrewrite.java.migrate.guava.NoGuavaJava21
   - org.openrewrite.java.migrate.guava.NoGuavaCreateTempDir
   - org.openrewrite.java.migrate.guava.NoGuavaDirectExecutor
+  - org.openrewrite.java.migrate.guava.NoGuavaFunctionsCompose
   - org.openrewrite.java.migrate.guava.NoGuavaInlineMeMethods
   - org.openrewrite.java.migrate.guava.NoGuavaIterablesAnyFilter
   - org.openrewrite.java.migrate.guava.NoGuavaListsNewArrayList

src/test/java/org/openrewrite/java/migrate/guava/NoGuavaFunctionsComposeTest.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2025 the original author or authors.
+ * <p>
+ * Licensed under the Moderne Source Available License (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://docs.moderne.io/licensing/moderne-source-available-license
+ * <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.migrate.guava;
+
+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 NoGuavaFunctionsComposeTest implements RewriteTest {
+
+    @Override
+    public void defaults(RecipeSpec spec) {
+        spec
+          .recipe(new NoGuavaFunctionsCompose())
+          .parser(JavaParser.fromJavaVersion().classpathFromResources(new InMemoryExecutionContext(), "guava"));
+    }
+
+    @DocumentExample
+    @Test
+    void replaceFunctionsCompose() {
+        //language=java
+        rewriteRun(
+          java(
+            """
+              import com.google.common.base.Function;
+              import com.google.common.base.Functions;
+
+              class Test {
+                  public static void test() {
+                      Function<Object, Integer> composed = Functions.compose(new Function<String, Integer>() {
+                          @Override
+                          public Integer apply(String input) {
+                              return input.length();
+                          }
+                      }, new Function<Object, String>() {
+                          @Override
+                          public String apply(Object input) {
+                              return input.toString();
+                          }
+                      });
+                  }
+              }
+              """,
+            """
+              import com.google.common.base.Function;
+
+              class Test {
+                  public static void test() {
+                      Function<Object, Integer> composed = new Function<String, Integer>() {
+                          @Override
+                          public Integer apply(String input) {
+                              return input.length();
+                          }
+                      }.compose(new Function<Object, String>() {
+                          @Override
+                          public String apply(Object input) {
+                              return input.toString();
+                          }
+                      });
+                  }
+              }
+              """
+          )
+        );
+    }
+}