Recipes to replace Guava Immutable{Set|List|Map}.copyOf() with Java {Set|List|Map}.copyOf()

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "java.compile.nullAnalysis.mode": "automatic"
+}

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

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+/*
+ * Copyright 2023 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.migrate.guava;
+
+import org.jspecify.annotations.Nullable;
+import org.openrewrite.ExecutionContext;
+import org.openrewrite.Preconditions;
+import org.openrewrite.Recipe;
+import org.openrewrite.TreeVisitor;
+import org.openrewrite.java.JavaTemplate;
+import org.openrewrite.java.JavaVisitor;
+import org.openrewrite.java.MethodMatcher;
+import org.openrewrite.java.search.UsesJavaVersion;
+import org.openrewrite.java.search.UsesType;
+import org.openrewrite.java.tree.*;
+
+import java.time.Duration;
+
+abstract class AbstractNoGuavaImmutableCopyOf extends Recipe {
+
+    private final String guavaType;
+    private final String javaType;
+
+    AbstractNoGuavaImmutableCopyOf(String guavaType, String javaType) {
+        this.guavaType = guavaType;
+        this.javaType = javaType;
+    }
+
+    private String getShortType(String fullyQualifiedType) {
+        return fullyQualifiedType.substring(javaType.lastIndexOf(".") + 1);
+    }
+
+    @Override
+    public String getDisplayName() {
+        return "Prefer `" + getShortType(javaType) + ".copyOf(..)` in Java 10 or higher";
+    }
+
+    @Override
+    public String getDescription() {
+        return "Replaces `" + getShortType(guavaType) + ".copyOf(..)` if the returned type is immediately down-cast.";
+    }
+
+    @Override
+    public Duration getEstimatedEffortPerOccurrence() {
+        return Duration.ofMinutes(10);
+    }
+
+    @Override
+    public TreeVisitor<?, ExecutionContext> getVisitor() {
+        TreeVisitor<?, ExecutionContext> check = Preconditions.and(new UsesJavaVersion<>(10),
+                new UsesType<>(guavaType, false));
+        final MethodMatcher IMMUTABLE_MATCHER = new MethodMatcher(guavaType + " copyOf(..)");
+        return Preconditions.check(check, new JavaVisitor<ExecutionContext>() {
+            @Override
+            public J visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx) {
+                if (IMMUTABLE_MATCHER.matches(method) && isParentTypeDownCast(method)) {
+                    maybeRemoveImport(guavaType);
+                    maybeAddImport(javaType);
+
+                    J.MethodInvocation templated = JavaTemplate.builder(getShortType(javaType) + ".copyOf(#{any()})")
+                            .imports(javaType)
+                            .build()
+                            .apply(getCursor(),
+                                    method.getCoordinates().replace(),
+                                    method.getArguments().get(0));
+                    return templated.getPadding().withArguments(method.getPadding().getArguments());
+                }
+                return super.visitMethodInvocation(method, ctx);
+            }
+
+            private boolean isParentTypeDownCast(MethodCall immutableMethod) {
+                J parent = getCursor().dropParentUntil(J.class::isInstance).getValue();
+                boolean isParentTypeDownCast = false;
+                if (parent instanceof J.VariableDeclarations.NamedVariable) {
+                    isParentTypeDownCast = isParentTypeMatched(((J.VariableDeclarations.NamedVariable) parent).getType());
+                } else if (parent instanceof J.Assignment) {
+                    J.Assignment a = (J.Assignment) parent;
+                    if (a.getVariable() instanceof J.Identifier && ((J.Identifier) a.getVariable()).getFieldType() != null) {
+                        isParentTypeDownCast = isParentTypeMatched(((J.Identifier) a.getVariable()).getFieldType().getType());
+                    } else if (a.getVariable() instanceof J.FieldAccess) {
+                        isParentTypeDownCast = isParentTypeMatched(a.getVariable().getType());
+                    }
+                } else if (parent instanceof J.Return) {
+                    // Does not currently support returns in lambda expressions.
+                    J j = getCursor().dropParentUntil(is -> is instanceof J.MethodDeclaration || is instanceof J.CompilationUnit).getValue();
+                    if (j instanceof J.MethodDeclaration) {
+                        TypeTree returnType = ((J.MethodDeclaration) j).getReturnTypeExpression();
+                        if (returnType != null) {
+                            isParentTypeDownCast = isParentTypeMatched(returnType.getType());
+                        }
+                    }
+                } else if (parent instanceof J.MethodInvocation) {
+                    J.MethodInvocation m = (J.MethodInvocation) parent;
+                    int index = m.getArguments().indexOf(immutableMethod);
+                    if (m.getMethodType() != null && index != -1) {
+                        isParentTypeDownCast = isParentTypeMatched(m.getMethodType().getParameterTypes().get(index));
+                    }
+                } else if (parent instanceof J.NewClass) {
+                    J.NewClass c = (J.NewClass) parent;
+                    int index = 0;
+                    if (c.getConstructorType() != null) {
+                        for (Expression argument : c.getArguments()) {
+                            if (IMMUTABLE_MATCHER.matches(argument)) {
+                                break;
+                            }
+                            index++;
+                        }
+                        if (c.getConstructorType() != null) {
+                            isParentTypeDownCast = isParentTypeMatched(c.getConstructorType().getParameterTypes().get(index));
+                        }
+                    }
+                } else if (parent instanceof J.NewArray) {
+                    J.NewArray a = (J.NewArray) parent;
+                    JavaType arrayType = a.getType();
+                    while (arrayType instanceof JavaType.Array) {
+                        arrayType = ((JavaType.Array) arrayType).getElemType();
+                    }
+
+                    isParentTypeDownCast = isParentTypeMatched(arrayType);
+                }
+                return isParentTypeDownCast;
+            }
+
+            private boolean isParentTypeMatched(@Nullable JavaType type) {
+                JavaType.FullyQualified fq = TypeUtils.asFullyQualified(type);
+                return TypeUtils.isOfClassType(fq, javaType) ||
+                       TypeUtils.isOfClassType(fq, "java.lang.Object");
+            }
+        });
+    }
+}

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

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2023 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.migrate.guava;
+
+public class NoGuavaImmutableListCopyOf extends AbstractNoGuavaImmutableCopyOf {
+    public NoGuavaImmutableListCopyOf() {
+        super("com.google.common.collect.ImmutableList", "java.util.List");
+    }
+}

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

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2023 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.migrate.guava;
+
+public class NoGuavaImmutableMapCopyOf extends AbstractNoGuavaImmutableCopyOf {
+    public NoGuavaImmutableMapCopyOf() {
+        super("com.google.common.collect.ImmutableMap", "java.util.Map");
+    }
+}

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

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2023 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.migrate.guava;
+
+public class NoGuavaImmutableSetCopyOf extends AbstractNoGuavaImmutableCopyOf {
+    public NoGuavaImmutableSetCopyOf() {
+        super("com.google.common.collect.ImmutableSet", "java.util.Set");
+    }
+}

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

@@ -77,6 +77,9 @@ recipeList:
   - org.openrewrite.java.migrate.guava.NoGuavaImmutableListOf
   - org.openrewrite.java.migrate.guava.NoGuavaImmutableMapOf
   - org.openrewrite.java.migrate.guava.NoGuavaImmutableSetOf
+  - org.openrewrite.java.migrate.guava.NoGuavaImmutableSetCopyOf
+  - org.openrewrite.java.migrate.guava.NoGuavaImmutableListCopyOf
+  - org.openrewrite.java.migrate.guava.NoGuavaImmutableMapCopyOf
   - org.openrewrite.java.migrate.guava.PreferJavaUtilObjectsRequireNonNullElse
   - org.openrewrite.java.dependencies.UpgradeDependencyVersion:
       groupId: io.springfox