Support changing from a constructor to a factory method in ChangeMethodTargetToStatic (#1804) (#7281)

Author: timtebeek

rewrite-java-test/src/test/java/org/openrewrite/java/ChangeMethodTargetToStaticTest.java

@@ -304,6 +304,129 @@ public void test() {
         );
     }
 
+    @Issue("https://github.com/openrewrite/rewrite/issues/1804")
+    @Test
+    void constructorToStaticMethod() {
+        rewriteRun(
+          spec -> spec.recipes(
+            new ChangeMethodTargetToStatic("a.A <constructor>(String)", "b.B", "b.B", null, false),
+            new ChangeMethodName("b.B A(String)", "foo", null, null)
+          ),
+          java(
+            """
+              package a;
+              public class A {
+                 public A(String s) {}
+              }
+              """
+          ),
+          java(
+            """
+              package b;
+              public class B {
+                 public static B foo(String s) { return null; }
+              }
+              """
+          ),
+          java(
+            """
+              import a.A;
+              class C {
+                 public void test() {
+                     new A("hello");
+                 }
+              }
+              """,
+            """
+              import b.B;
+
+              class C {
+                 public void test() {
+                     B.foo("hello");
+                 }
+              }
+              """
+          )
+        );
+    }
+
+    @Issue("https://github.com/openrewrite/rewrite/issues/1804")
+    @Test
+    void constructorToStaticMethodWithReturnType() {
+        rewriteRun(
+          spec -> spec.recipe(
+            new ChangeMethodTargetToStatic("a.A <constructor>(String)", "b.B", "b.B", null, false)
+          ),
+          java(
+            """
+              package a;
+              public class A {
+                 public A(String s) {}
+              }
+              """
+          ),
+          java(
+            """
+              package b;
+              public class B {
+                 public static B A(String s) { return null; }
+              }
+              """
+          ),
+          java(
+            """
+              import a.A;
+              class C {
+                 public void test() {
+                     new A("hello");
+                 }
+              }
+              """,
+            """
+              import b.B;
+
+              class C {
+                 public void test() {
+                     B.A("hello");
+                 }
+              }
+              """
+          )
+        );
+    }
+
+    @Issue("https://github.com/openrewrite/rewrite/issues/1804")
+    @Test
+    void constructorWithAnonymousBodyNotChanged() {
+        rewriteRun(
+          spec -> spec.recipe(
+            new ChangeMethodTargetToStatic("a.A <constructor>(String)", "b.B", "b.B", null, false)
+          ),
+          java(
+            """
+              package a;
+              public class A {
+                 public A(String s) {}
+                 public void doSomething() {}
+              }
+              """
+          ),
+          java(
+            """
+              import a.A;
+              class C {
+                 public void test() {
+                     new A("hello") {
+                         @Override
+                         public void doSomething() {}
+                     };
+                 }
+              }
+              """
+          )
+        );
+    }
+
     @Disabled
     @Issue("https://github.com/openrewrite/rewrite/issues/3085")
     @SuppressWarnings("ResultOfMethodCallIgnored")

rewrite-java/src/main/java/org/openrewrite/java/ChangeMethodTargetToStatic.java

@@ -98,7 +98,7 @@ public TreeVisitor<?, ExecutionContext> getVisitor() {
         return matchUnknown ? visitor : Preconditions.check(new UsesMethod<>(methodPattern, matchOverrides), visitor);
     }
 
-    private class ChangeMethodTargetToStaticVisitor extends JavaIsoVisitor<ExecutionContext> {
+    private class ChangeMethodTargetToStaticVisitor extends JavaVisitor<ExecutionContext> {
         private final MethodMatcher methodMatcher;
         private final boolean matchUnknownTypes;
         private final JavaType.FullyQualified classType = JavaType.ShallowClass.build(fullyQualifiedTargetTypeName);
@@ -136,8 +136,8 @@ private JavaType.Method transformMethodType(JavaType.Method methodType) {
         }
 
         @Override
-        public J.MethodInvocation visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx) {
-            J.MethodInvocation m = super.visitMethodInvocation(method, ctx);
+        public J visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx) {
+            J.MethodInvocation m = (J.MethodInvocation) super.visitMethodInvocation(method, ctx);
             Expression select = method.getSelect();
             if (!isAlreadyStaticCallOnTargetType(select, method) &&
                 methodMatcher.matches(method, matchUnknownTypes)) {
@@ -170,8 +170,8 @@ public J.MethodInvocation visitMethodInvocation(J.MethodInvocation method, Execu
         }
 
         @Override
-        public J.MemberReference visitMemberReference(J.MemberReference memberRef, ExecutionContext ctx) {
-            J.MemberReference m = super.visitMemberReference(memberRef, ctx);
+        public J visitMemberReference(J.MemberReference memberRef, ExecutionContext ctx) {
+            J.MemberReference m = (J.MemberReference) super.visitMemberReference(memberRef, ctx);
             Expression containing = memberRef.getContaining();
             if (!isAlreadyStaticCallOnTargetType(containing, memberRef) &&
                 methodMatcher.matches(memberRef)) {
@@ -195,5 +195,62 @@ public J.MemberReference visitMemberReference(J.MemberReference memberRef, Execu
             }
             return m;
         }
+
+        @Override
+        public J visitNewClass(J.NewClass newClass, ExecutionContext ctx) {
+            J.NewClass n = (J.NewClass) super.visitNewClass(newClass, ctx);
+            if (n.getBody() != null || n.getEnclosing() != null) {
+                return n;
+            }
+            if (methodMatcher.matches(n)) {
+                String methodName;
+                JavaType.Method transformedType = null;
+                if (n.getConstructorType() != null) {
+                    methodName = n.getConstructorType().getConstructorName();
+                    if (methodName == null) {
+                        return n;
+                    }
+                    maybeRemoveImport(n.getConstructorType().getDeclaringType());
+                    transformedType = transformMethodType(n.getConstructorType())
+                            .withName(methodName);
+                } else {
+                    return n;
+                }
+
+                maybeAddImport(fullyQualifiedTargetTypeName, !matchUnknownTypes);
+
+                J.Identifier selectId = new J.Identifier(
+                        randomId(),
+                        n.getPrefix(),
+                        Markers.EMPTY,
+                        emptyList(),
+                        classType.getClassName(),
+                        classType,
+                        null
+                );
+
+                J.Identifier nameId = new J.Identifier(
+                        randomId(),
+                        Space.EMPTY,
+                        Markers.EMPTY,
+                        emptyList(),
+                        methodName,
+                        transformedType,
+                        null
+                );
+
+                return new J.MethodInvocation(
+                        randomId(),
+                        Space.EMPTY,
+                        Markers.EMPTY,
+                        JRightPadded.build(selectId),
+                        null,
+                        nameId,
+                        n.getPadding().getArguments(),
+                        transformedType
+                );
+            }
+            return n;
+        }
     }
 }